This scorching hot nightmare planet just opened up avenues for finding alien life – Astronomy Magazine

On the list of exoplanets that could hold life, GJ 1132b wouldnt come near making the cut. Its a super-Earth whose upper atmosphere reaches 500 degrees Fahrenheit (260 degrees Celcius), meaning it only gets hotter as you move down. Its barely a hair away from its star, completing a year in 1.6 Earth days.

Life is incredibly unlikely to survive there. Yet it may be one of the most important planets to come along in the search for life. So whys that?

Well, its because it has an atmosphere at all.

GJ 1132b orbits an M-dwarf star. M-dwarfs are the most numerous stars known in the universe, but also some of the most turbulent. While they can last trillions of years, the first few billion years of their lives are spent expelling violent flare events.

Most of these M-dwarfs likely have planets, and a handful of known planets around these stars are in the habitable zone. These early flare events may sweep away those atmospheres, leaving what could have held liquid pools of water and an Earth-like atmosphere instead barren rocks.

And yet GJ 1132b has an atmosphere, according to research from the European Southern Observatory and the Max Planck Institute. The atmosphere appears to have abundant water vapor and methane with a similar thickness to that of Venus.

The research, published in The Astronomical Journal, suggests that planets around M-dwarf stars can retain atmospheres even after their turbulent early years. GJ 1132b, which is about 39 light years away, is considered an older planet. Thus, other M-dwarf planets might be able to retain their atmospheres, and planets in the habitable zone could have a way to actually host life rather than showing false promise.

Instruments like the James Webb Space Telescope may be able to glance at other M-dwarf planets to see if atmospheric retention is common or if 1132b is an outlier.

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This scorching hot nightmare planet just opened up avenues for finding alien life - Astronomy Magazine

Solar Eclipse Featured at Astronomy Day on April 29 – YubaNet

The solar eclipse shot was taken by David Buchla off the coast of Tahiti from a cruise ship on July 11, 2010. Details are: Canon EOS 5D Mk 2 camera with a Canon 300 mm f2.8 lens with 1.4 multiplier for an equivalent focal length of 420 mm.

NEVADA CITY, Calif. April 6, 2017 The Nevada County Astronomy Club and the Madelyn Helling Library host Astronomy Day on Saturday, April 29, 2017 from 11 am to 3 pm. Astronomy Day features numerous educational exhibits about our place in the universe. This years theme, Eclipses includes an introduction to this summers solar eclipse. It will be the first in the continental US since February 26, 1979.

This years eclipse promises to be widely visible as it crosses the United States. Astronomy Day attendees will learn more about this spectacular event during the Solar Eclipse lecture that will take place in the new Marian E. Gallaher Amphitheater at the Madelyn Helling Library, 980 Helling Way in Nevada City, California.

Astronomy Day is an annual event established to highlight the science as a fun and educational hobby and to bring awareness to our amazing universe. It isnt necessary to have a telescope to appreciate the night sky and to learn more about it.

Nevada County Astronomers hold regular meeting on topics of general interest and schedule events to share their knowledge with schools and the public.

Astronomy Day features fun activities for the whole family. The highlight of the day is a Star Lab planetarium show, The Color of Stars. The presentations are hosted by long time astronomer Larry Harrison, an expert in conducting these shows for schools and community groups.

The planetarium is a large inflatable dome that offers visitors a chance to see the night sky in a dark environment. Regular shows will be given from noon to 3 pm; no tickets or reservation required.

Solar telescopes will be set up for safe viewing the sun (weather permitting) in both white light and hydrogen-alpha light. Visitors will be able to make their own star wheels to help navigate the night sky. Star wheels show constellations that are in the sky at any time and date. Another popular activity for kids is the Hands-on Science exhibit and the Demonstration Science tables. Displays include a wide variety of astronomy related topics from auroras, moon exploration, the New Horizon mission to Pluto, eclipses and much more. Several talks will be given in the afternoon including one on the upcoming eclipse.

Outside activities include a planet walk with a full-scale model of the solar system out to Mars. The model helps persons taking the walk understand how enormous our solar system really is. Everyone is welcome and there is no charge. For more information and a schedule, go to http://www.ncastronomers.org.

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Solar Eclipse Featured at Astronomy Day on April 29 - YubaNet

Could Mysterious Fast Radio Bursts Be Powering Extragalactic Light Sails? – Sci-News.com

Fast radio bursts (FRBs) powerful radio flashes lasting just milliseconds, with mysterious origins that continue to be a matter of debate could be evidence of advanced alien technology, new research from Harvard suggests. Specifically, FRBs might be leakage from transmitters powering giant light sail probes in galaxies other than our own.

An artists illustration of a light-sail powered by a radio beam (red) generated on the surface of an exoplanet. The leakage from such beams as they sweep across the sky would appear as FRBs. Image credit: M. Weiss / CfA.

FRBs are mysterious and rarely detected bursts of radio emission that have durations of milliseconds and exhibit the characteristic dispersion sweep of radio pulsars.

These events emit as much energy in one millisecond as the Sun emits in 10,000 years, but the physical phenomenon that causes them is unknown.

The first FRB was discovered in 2007, although it was actually observed some six years earlier, in archival data from a pulsar survey of the Magellanic Clouds.

Only 18 FRBs have been detected to date. Most give off only a single burst and do not flash repeatedly.

They are inferred to originate from distant galaxies, billions of light-years away.

Avi Loeb, the Chair of the Astronomy Department and the Frank B. Baird Jr. Professor of Science at Harvard University, and his colleague at Harvard, Manasvi Lingam, examined the feasibility of creating a radio transmitter strong enough for it to be detectable across such immense distances.

The team found that, if the transmitter were solar powered, the sunlight falling on an area of an exoplanet twice the size of the Earth would be enough to generate the needed energy.

Such a vast construction project is well beyond our technology, but within the realm of possibility according to the laws of physics.

The researchers also considered whether such a transmitter would be viable from an engineering perspective, or whether the tremendous energies involved would melt any underlying structure.

Again, they found that a water-cooled device twice the size of Earth could withstand the heat.

They then asked, why build such an instrument in the first place?

They argue that the most plausible use of such power is driving interstellar light sails.

The amount of power involved would be sufficient to push a payload of a million tons, or about 20 times the largest cruise ships on Earth.

Thats big enough to carry living passengers across interstellar or even intergalactic distances, Dr. Lingam said.

To power a light sail, the transmitter would need to focus a beam on it continuously.

Observers on Earth would see a brief flash because the sail and its host planet, star and galaxy are all moving relative to us.

As a result, the beam sweeps across the sky and only points in our direction for a moment.

Repeated appearances of the beam, which were observed but cannot be explained by cataclysmic astrophysical events, might provide important clues about its artificial origin.

FRBs are exceedingly bright given their short duration and origin at great distances, and we havent identified a possible natural source with any confidence. An artificial origin is worth contemplating and checking, said Prof. Loeb, who also chairs the Advisory Committee for the Breakthrough Starshot Initiative and serves as the Science Theory Director for all Initiatives of the Breakthrough Prize Foundation.

He admits that this work is speculative. When asked whether he really believes that any fast radio bursts are due to aliens, he replied, Science isnt a matter of belief, its a matter of evidence. Deciding whats likely ahead of time limits the possibilities. Its worth putting ideas out there and letting the data be the judge.

The paper reporting this work has been accepted for publication in the Astrophysical Journal Letters, but has been published on arXiv.org ahead of time.

_____

Manasvi Lingam & Abraham Loeb. 2017. Fast Radio Bursts from Extragalactic Light Sails. ApJL, in press; arXiv: 1701.01109

This article is based on a press-release from the Harvard-Smithsonian Center for Astrophysics.

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Could Mysterious Fast Radio Bursts Be Powering Extragalactic Light Sails? - Sci-News.com

BREAKING NEWS: Scott Pruitt, head of EPA, doesn’t think carbon dioxide is the main driver of global warming – Blastr

[Credit: Shutterstock / Barnaby Chambers]

Hot on the heels of my post earlier today about the reality of global warming comes this jaw-dropper: Scott Pruitt, who was recently approved by the Senate to run the United States Environmental Protection Agency (EPA), says that carbon dioxide is not the main cause of global warming.

Holy. Wow.

In a CNBC interview, when asked, Do you believe that its been proven that CO2 is the primary control knob for climate? he replied this way:

No, I think that measuring with precision human activity on the climate is something very challenging to do and theres tremendous disagreement about the degree of impact. So no, I would not agree that its a primary contributor to the global warming that we see.

This is science denialism at a stunning level. And its incredibly disingenuous, too. Note his phrasing: Hes saying that disagreement about the amount of human-caused warming means CO2 is not the primary driver of warming. Thats like saying, I dont know if theres a traffic jam at the corner of Main and 1st street or Main and 2nd, therefore cars dont exist.

Thats a classic denial method of distraction, sowing confusion about one issue to downplay another. Not only that, its utter baloney. We know for a fact that carbon dioxide is a greenhouse gas, and the main driver for the increased global warming weve seen over the past few decades. We also know for a fact that all or nearly all of that warming weve seen is caused by human activity.

The science behind greenhouse gases is pretty simple (and in fact understood for a century or so). A gas like carbon dioxide is transparent to visible light. Sunlight passes right by CO2 in the air, and hits the ground, warming it up. A warm object emits infrared light, so the ground radiates that absorbed energy from sunlight back into the sky. But CO2 is not transparent to infrared; it absorbs some of it, trapping a little bit of extra heat on Earth.

There are other greenhouse gases, including water vapor and methane. But, in general, the amounts of these gases in the atmosphere are in balance; water vapor condenses to form liquid water at about the same rate it vaporizes, so the amount in the air is steady. Methane is a very fragile molecule, and doesnt last long once its in the atmosphere (ironically, it breaks down into carbon dioxide and water). So, while these are actually stronger greenhouse gases per molecule than CO2, they are in balance in the air, and dont contribute much to rising temperatures.

The reason CO2 is the main driver of global warming is that we humans are producing prodigious quantities of it and dumping it into the air. How much? 40 billion tons per year. Yes, billion. Thats far more than any other natural source on the planet (even a big volcanic eruption puts out far less than that, despite claims by many deniers).

Thats why were getting hotter. Its the extra CO2 in the air over time thats trapping more heat from sunlight, warming us up. If we werent putting that extra carbon dioxide in the atmosphere we wouldnt be experiencing global warming as we are. Also, CO2 is a very stable molecule, so any of it we put in the air stays there, lasting for decades or even centuries.

As to Pruitts second point, computer models that take into account all known physical factors show that humans are not only the main cause of warming, but that we may be causing all of it. Like 100%.

The graphic shows this; various models using different methods all show that humans are behind the vast majority of extra warming we see. Natural factors cause very little. In fact, many natural factors actually cool the planet, but were so vigorously churning out CO2 that were actually reversing that! Thats how humans can actually cause more than 100% of the warming.

The confusion Pruitt is sowing is due to a very minor point: The question of just how much temperatures go up as CO2 increases. If you double the CO2 in the air, for example, does the temperature go up 2 Celsius, or 3 or 4? This is a complicated question, because in the short term the temperature may only go up a degree or so, but over time an equilibrium is reached that can be much higher, like 3-4. But no matter what, Pruitt is still bearing false witness: We know the temperature is going up, and we know its from CO2, and we know its the extra CO2 were generating thats doing it.

So, everything Pruitt said in that short answer was complete nonsense. I just wish it were unexpected; its been clear for some time that nearly every single person Donald Trump has nominated to a position of power denies global warming.

But thats why this is so very serious. Pruitt is the head of the EPA, the agency created to make sure we humans dont screw up our environment. The EPA was created under Nixon and has been amazingly successful at cleaning up the disasters humans have left behind us as our technology grows. Its been vital in preventing future disasters, too. This includes the effects of global warming. Thats why the EPA classified CO2 as a pollutant; that way it can be regulated so that we dont pour even more of it into the air by burning fossil fuels.

And that is why so many scientists are up in arms over the Trump administration's bizarre and terrible appointees to science agencies, like Pruitt. They arent just ignorant of basic science;theyre openly antagonistic toward it. And thats why we must continue to speak up, make our voices heard, and do what we can to prevent these people for destroying the one planet weve got.

They want to turn up the heat on Earth? Then we must turn the heat up on them.

Continued here:

BREAKING NEWS: Scott Pruitt, head of EPA, doesn't think carbon dioxide is the main driver of global warming - Blastr

Chinese astronomy – Wikipedia

Astronomy in China has a very long history, with historians indicating that the Chinese were the most persistent and accurate observers of celestial phenomena anywhere in the world before the Arabs.[1] Star names later categorized in the twenty-eight mansions have been found on oracle bones unearthed at Anyang, dating back to the middle Shang Dynasty (Chinese Bronze Age), and the mansion (xi:) system's nucleus seems to have taken shape by the time of the ruler Wu Ding (1339-1281 BC).[2]

Detailed records of astronomical observations began during the Warring States period (fourth century BC) and flourished from the Han period onward. Chinese astronomy was equatorial, centered as it was on close observation of circumpolar stars, and was based on different principles from those prevailing in traditional Western astronomy, where heliacal risings and settings of zodiac constellations formed the basic ecliptic framework.[3]

Some elements of Indian astronomy reached China with the expansion of Buddhism after the Eastern Han Dynasty (25220 AD), but the most detailed incorporation of Indian astronomical thought occurred during the Tang Dynasty (618-907), when numerous Indian astronomers took up residence in the Chinese capital, and Chinese scholars, such as the great Tantric Buddhist monk and mathematician Yi Xing, mastered its system. Islamic astronomers collaborated closely with their Chinese colleagues during the Yuan Dynasty, and, after a period of relative decline during the Ming Dynasty, astronomy was revitalized under the stimulus of Western cosmology and technology after the Jesuits established their missions. The telescope was introduced in the seventeenth century. In 1669, the Peking observatory was completely redesigned and refitted under the direction of Ferdinand Verbiest. Today, China continues to be active in astronomy, with many observatories and its own space program.

One of the main functions was for the purpose of timekeeping. The Chinese used a lunisolar calendar, but, because the cycles of the sun and the moon are different, intercalation had to be done.

The Chinese calendar was considered to be a symbol of a dynasty. As dynasties would rise and fall, astronomers and astrologers of each period would often prepare a new calendar to be made, with observations for that purpose.

Astrological divination was also an important part of astronomy. Astronomers took careful note of "guest stars", which suddenly appeared among the fixed stars. The supernova that created the Crab Nebula observed in 1054, now known as the SN 1054, is an example of a guest star observed by Chinese astronomers, recorded also by the Arab astronomers, although it was not recorded by their European contemporaries. Ancient astronomical records of phenomena like comets and supernovae are sometimes used in modern astronomical studies.

The Chinese developed three different cosmological models. The Gai Tian, or hemispherical dome, model conceived the heavens as a hemisphere lying over a dome-shaped earth. The second cosmological model, associated with the Hun Tian school, saw the heavens as a celestial sphere not unlike the spherical models developed in the Greek and Hellenistic traditions. The third cosmology, associated with the Xuan Ye school, viewed the heavens as infinite in extent and the celestial bodies as floating about at rare intervals, and "the speed of the luminaries depends on their individual natures, which shows they are not attached to anything."[5]

The divisions of the sky began with the Northern Dipper and the 28 mansions.

In 1977, a lacquer box was excavated from the tomb of Yi, the marquis of Zeng, in Suixian, Hubei Province. Names of the 28 lunar mansions were found on the cover of the box, proving that the use of this classification system was made before 433 BC.

As lunar mansions have such an ancient origin, the meanings of most of their names have become obscure. Even worse, the name of each lunar mansion consists of only one Chinese word, the meaning of which could vary at different times in history. The meanings of the names are still under discussion.

Besides the 28 lunar mansions, most constellations are based on the works of Shi Shen-fu and Gan De, who were astrologists during the period of Warring States (481 BC - 221 BC) in China.

In the late period of the Ming Dynasty, the agricultural scientist and mathematician Xu Guangqi (1562 - 1633 AD) introduced 23 additional constellations near to the Celestial South Pole, which are based on star catalogues from the West (see Matteo Ricci).

In the fourth century BC, the two Chinese astronomers responsible for the earliest information going into the star catalogues were Shi Shen and Gan De of the Warring States period.[6]

These books appeared to have lasted until the sixth century, but were lost after that.[6] A number of books share similar names, often quoted and named after them. These texts should not be confused with the original catalogues written by them. Notable works that helped preserve the contents include:

Wu Xian () has been one of the astronomers in debate. He is often represented as one of the "Three Schools Astronomical tradition" along with Gan and Shi.[11] The Chinese classic text Star Manual of Master Wu Xian () and its authorship is still in dispute, because it mentioned names of twelve countries that did not exist in the Shang Dynasty, the era of which it was supposed to have been written. Moreover, it was customary in the past for the Chinese to forge works of notable scholars, as this could lead to a possible explanation for the inconsistencies found. Wu Xian is generally mentioned as the astronomer who lived many years before Gan and Shi.

The Han Dynasty astronomer and inventor Zhang Heng (78-139AD) not only catalogued some 2500 different stars, but also recognized more than 100 different constellations. Zhang Heng also published his work Ling Xian, a summary of different astronomical theories in China at the time. In the subsequent period of the Three Kingdoms (220-280AD), Chen Zhuo () combined the work of his predecessors, forming another star catalogue. This time, 283 constellations and 1464 stars were listed. The astronomer Guo Shoujin of the Yuan Dynasty (1279-1368AD) created a new catalogue, which was believed to contain thousands of stars. Unfortunately, many of the documents of that period were destroyed, including that of Shoujin. Imperial Astronomical Instruments () was published in 1757 and contains 3083 stars exactly.

The Chinese drew many maps of stars in the past centuries. It is debatable as to which counts as the oldest star maps, since pottery and old artifacts can also be considered star maps. One of the oldest existent star maps in printed form is from Su Song's (1020-1101AD) celestial atlas of 1092AD, which was included in the horological treatise on his clocktower. The most famous one is perhaps the Dunhuang map found in Dunhuang, Gansu. Uncovered by the British archaeologist Marc Aurel Stein in 1907, the star map was brought to the British Museum in London. The map was drawn on paper and represents the complete sky, with more than 1,350 stars. Although ancient Babylonians and Greeks also observed the sky and catalogued stars, no such complete record of the stars may exist or survive. Hence, this is the oldest chart of the skies at present.

According to recent studies, the map may date the manuscript to as early as the seventh century AD (Tang Dynasty). Scholars believe the star map dating from 705 to 710AD, which is the reign of Emperor Zhongzong of Tang. There are some texts (Monthly Ordinances, ) describing the movement of the sun among the sky each month, which was not based on the observation at that time.

Chinese astronomers recorded 1,600 observations of solar and lunar eclipses from 750 BC.[12] The ancient Chinese astronomer Shi Shen (fl. fourth century BC) was aware of the relation of the moon in a solar eclipse, as he provided instructions in his writing to predict them by using the relative positions of the moon and the sun.[13] The radiating-influence theory, where the moon's light was nothing but a reflection of the sun's, was supported by the mathematician and music theorist Jing Fang (7837BC), yet opposed by the Chinese philosopher Wang Chong (2797AD), who made clear in his writing that this theory was nothing new.[14] Jing Fang wrote:

The moon and the planets are Yin; they have shape but no light. This they receive only when the sun illuminates them. The former masters regarded the sun as round like a crossbow bullet, and they thought the moon had the nature of a mirror. Some of them recognized the moon as a ball too. Those parts of the moon which the sun illuminates look bright, those parts which it does not, remain dark.[15]

The ancient Greeks had known this as well, since Parmenides and Aristotle supported the theory of the moon shining because of reflected light.[15] The Chinese astronomer and inventor Zhang Heng (78139AD) wrote of both solar eclipse and lunar eclipse in the publication of Ling Xian (), 120AD:

The sun is like fire and the moon like water. The fire gives out light and the water reflects it. Thus the moon's brightness is produced from the radiance of the sun, and the moon's darkness (pho) is due to (the light of) the sun being obstructed (pi). The side which faces the sun is fully lit, and the side which is away from it is dark. The planets (as well as the moon) have the nature of water and reflect light. The light pouring forth from the sun (tang jih chih chhung kuang) does not always reach the moon owing to the obstruction (pi) of the earth itselfthis is called 'an-hs', a lunar eclipse. When (a similar effect) happens with a planet (we call it) an occulation (hsing wei); when the moon passes across (kuo) (the sun's path) then there is a solar eclipse (shih).[16]

The later Song Dynasty scientist Shen Kuo (10311095) used the models of lunar eclipse and solar eclipse in order to prove that the celestial bodies were round, not flat. This was an extension of the reasoning of Jing Fang and other theorists as early as the Han Dynasty. In his Dream Pool Essays of 1088AD, Shen related a conversation he had with the director of the Astronomical Observatory, who had asked Shen if the shapes of the sun and the moon were round like balls or flat like fans. Shen Kuo explained his reasoning for the former:

If they were like balls they would surely obstruct each other when they met. I replied that these celestial bodies were certainly like balls. How do we know this? By the waxing and waning of the moon. The moon itself gives forth no light, but is like a ball of silver; the light is the light of the sun (reflected). When the brightness is first seen, the sun (-light passes almost) alongside, so the side only is illuminated and looks like a crescent. When the sun gradually gets further away, the light shines slanting, and the moon is full, round like a bullet. If half of a sphere is covered with (white) powder and looked at from the side, the covered part will look like a crescent; if looked at from the front, it will appear round. Thus we know that the celestial bodies are spherical.[17]

When he asked Shen Kuo why eclipses occurred only on an occasional basis while in conjunction and opposition once a day, Shen Kuo wrote:

I answered that the ecliptic and the moon's path are like two rings, lying one over the other, but distant by a small amount. (If this obliquity did not exist), the sun would be eclipsed whenever the two bodies were in conjunction, and the moon would be eclipsed whenever they were exactly in position. But (in fact) though they may occupy the same degree, the two paths are not (always) near (each other), and so naturally the bodies do not (intrude) upon one another.[17]

The earliest development of the armillary sphere in China goes back to the 1st century BCE.,[18] as they were equipped with a primitive single-ring armillary instrument.This would have allowed them to measure the north polar distance (, the Chinese form of declination) and measurement that gave the position in a hsiu (, the Chinese form of right ascension).[19]

During the Western Han Dynasty (202BC-9AD), additional developments made by the astronomers Luo Xiahong (), Xiangyu Wangren, and Geng Shouchang () advanced the use of the armillary in its early stage of evolution. In 52BC, it was the astronomer Geng Shou-chang who introduced the fixed equatorial ring to the armillary sphere.[19] In the subsequent Eastern Han Dynasty (23-220 AD) period, the astronomers Fu An and Jia Kui added the elliptical ring by 84AD.[19] With the famous statesman, astronomer, and inventor Zhang Heng (78-139AD), the sphere was totally completed in 125AD, with horizon and meridian rings.[19] It is of great importance to note that the world's first hydraulic (i.e., water-powered) armillary sphere was created by Zhang Heng, who operated his by use of an inflow clepsydra clock (see Zhang's article for more detail).

Designed by famous astronomer Guo Shoujing in 1276AD, it solved most problems found in armillary spheres at that time.

The primary structure of abridged armilla contains two large rings that are perpendicular to each other, of which one is parallel with the equatorial plane and is accordingly called "equatorial ring", and the other is a double ring that is perpendicular to the center of the equatorial ring, revolving around a metallic shaft, and is called "right ascension double ring".

The double ring holds within itself a sighting tube with crosshairs. When observing, astronomers would aim at the star with the sighting tube, whereupon the star's position could be deciphered by observing the dials of the equatorial ring and the right ascension double ring.

A foreign missionary melted the instrument in 1715AD. The surviving one was built in 1437AD and was taken to what is now Germany. It was then stored in a French Embassy in 1900, during the Eight-Nation Alliance. Under the pressure of international public discontent, Germany returned the instrument to China. In 1933, it was placed in Purple Mountain Observatory, which prevented it from being destroyed in the Japanese invasion. In the 1980s, it had become seriously eroded and rusted down and was nearly destroyed. In order to restore the device, the Nanjing government spent 11 months to repair it.

Besides star maps, the Chinese also made celestial globes, which show stars' positions like a star map and can present the sky at a specific time. Because of its Chinese name, it is often confused with the armillary sphere, which is just one word different in Chinese ( vs. ).

According to records, the first celestial globe was made by Geng Shou-chang () between 70BC and 50BC. In the Ming Dynasty, the celestial globe at that time was a huge globe, showing the 28 mansions, celestial equator and ecliptic. None of them have survived.

Celestial globes were named ("Miriam celestial bodies") in the Qing Dynasty. The one in Beijing Ancient Observatory was made by Belgian missionary Ferdinand Verbiest () in 1673AD. Unlike other Chinese celestial globes, it employs 360 degrees rather than the 365.24 degrees (which is a standard in ancient China). It is also the first Chinese globe that shows constellations near to the Celestial South Pole.

The inventor of the hydraulic-powered armillary sphere was Zhang Heng (78-139AD) of the Han Dynasty. Zhang was well known for his brilliant applications of mechanical gears, as this was one of his most impressive inventions (alongside his seismograph to detect the cardinal direction of earthquakes that struck hundreds of miles away).

Started by Su Song () and his colleagues in 1086AD and finished in 1092AD, his large astronomical clock tower featured an armillary sphere (), a celestial globe () and a mechanical chronograph. It was operated by an escapement mechanism and the earliest known chain drive. However, 35 years later, the invading Jurchen army dismantled the tower in 1127AD upon taking the capital of Kaifeng. The armillary sphere part was brought to Beijing, yet the tower was never successfully reinstated, not even by Su Song's son.

Fortunately, two versions of Su Song's treatise written on his clock tower have survived the ages, so that studying his astronomical clock tower is made possible through medieval texts.

The polymath Chinese scientist Shen Kuo (10311095) was not only the first in history to describe the magnetic-needle compass, but also made a more accurate measurement of the distance between the pole star and true north that could be used for navigation. Shen achieved this by making nightly astronomical observations along with his colleague Wei Pu, using Shen's improved design of a wider sighting tube that could be fixed to observe the pole star indefinitely. Along with the pole star, Shen Kuo and Wei Pu also established a project of nightly astronomical observation over a period of five successive years, an intensive work that even would rival the later work of Tycho Brahe in Europe. Shen Kuo and Wei Pu charted the exact coordinates of the planets on a star map for this project and created theories of planetary motion, including retrograde motion.

Buddhism first reached China during the Eastern Han Dynasty, and translation of Indian works on astronomy came to China by the Three Kingdoms era (220265CE). However, the most detailed incorporation of Indian astronomy occurred only during the Tang Dynasty (618-907), when a number of Chinese scholarssuch as Yi Xingwere versed both in Indian and Chinese astronomy. A system of Indian astronomy was recorded in China as Jiuzhi-li (718CE), the author of which was an Indian by the name of Qutan Xidaa translation of Devanagari Gotama Siddhathe director of the Tang dynasty's national astronomical observatory.[20]

The astronomical table of sines by the Indian astronomer and mathematician Aryabhatan was translated into the Chinese astronomical and mathematical book Treatise on Astrology of the Kaiyuan Era (Kaiyuan Zhanjing), compiled in 718AD during the Tang Dynasty.[10] The Kaiyuan Zhanjing was compiled by Gautama Siddha, an astronomer and astrologer born in Chang'an, and whose family was originally from India. He was also notable for his translation of the Navagraha calendar into Chinese.

Islamic influence on Chinese astronomy was first recorded during the Song dynasty when a Hui Muslim astronomer named Ma Yize introduced the concept of 7 days in a week and made other contributions.[21]

Islamic astronomers were brought to China in order to work on calendar making and astronomy during the Mongol Empire and the succeeding Yuan Dynasty.[22][23] The Chinese scholar Yel Chucai accompanied Genghis Khan to Persia in 1210 and studied their calendar for use in the Mongol Empire.[23]Kublai Khan brought Iranians to Beijing to construct an observatory and an institution for astronomical studies.[22]

Several Chinese astronomers worked at the Maragheh observatory, founded by Nasir al-Din al-Tusi in 1259 under the patronage of Hulagu Khan in Persia.[24] One of these Chinese astronomers was Fu Mengchi, or Fu Mezhai.[25]

In 1267, the Persian astronomer Jamal ad-Din, who previously worked at Maragha observatory, presented Kublai Khan with seven Persian astronomical instruments, including a terrestrial globe and an armillary sphere,[26] as well as an astronomical almanac, which was later known in China as the Wannian Li ("Ten Thousand Year Calendar" or "Eternal Calendar"). He was known as "Zhama Luding" in China, where, in 1271,[25] he was appointed by Khan as the first director of the Islamic observatory in Beijing,[24] known as the Islamic Astronomical Bureau, which operated alongside the Chinese Astronomical Bureau for four centuries. Islamic astronomy gained a good reputation in China for its theory of planetary latitudes, which did not exist in Chinese astronomy at the time, and for its accurate prediction of eclipses.[25]

Some of the astronomical instruments constructed by the famous Chinese astronomer Guo Shoujing shortly afterwards resemble the style of instrumentation built at Maragheh.[24] In particular, the "simplified instrument" (jianyi) and the large gnomon at the Gaocheng Astronomical Observatory show traces of Islamic influence.[27] While formulating the Shoushili calendar in 1281, Shoujing's work in spherical trigonometry may have also been partially influenced by Islamic mathematics, which was largely accepted at Kublai's court.[28] These possible influences include a pseudo-geometrical method for converting between equatorial and ecliptic coordinates, the systematic use of decimals in the underlying parameters, and the application of cubic interpolation in the calculation of the irregularity in the planetary motions.[27]

Emperor Taizu (r. 1368-1398) of the Ming Dynasty (13281398), in the first year of his reign (1368), conscripted Han and non-Han astrology specialists from the astronomical institutions in Beijing of the former Mongolian Yuan to Nanjing to become officials of the newly established national observatory.

That year, the Ming government summoned for the first time the astronomical officials to come south from the upper capital of Yuan. There were fourteen of them. In order to enhance accuracy in methods of observation and computation, Emperor Taizu reinforced the adoption of parallel calendar systems, the Han and the Hui. In the following years, the Ming Court appointed several Hui astrologers to hold high positions in the Imperial Observatory. They wrote many books on Islamic astronomy and also manufactured astronomical equipment based on the Islamic system.

The translation of two important works into Chinese was completed in 1383: Zij (1366) and al-Madkhal fi Sina'at Ahkam al-Nujum, Introduction to Astrology (1004).

In 1384, a Chinese astrolabe was made for observing stars based on the instructions for making multi-purposed Islamic equipment. In 1385, the apparatus was installed on a hill in northern Nanjing.

Around 1384, during the Ming Dynasty, Emperor Zhu Yuanzhang ordered the Chinese translation and compilation of Islamic astronomical tables, a task that was carried out by the scholars Mashayihei, a Muslim astronomer, and Wu Bozong, a Chinese scholar-official. These tables came to be known as the Huihui Lifa (Muslim System of Calendrical Astronomy), which was published in China a number of times until the early 18th century,[29] though the Qing Dynasty had officially abandoned the tradition of Chinese-Islamic astronomy in 1659.[30] The Muslim astronomer Yang Guangxian was known for his attacks on the Jesuit's astronomical sciences.

The introduction of Western science to China by Jesuit priest astronomers was a mixed blessing during the late sixteenth century and early seventeenth century.

The telescope was introduced to China in the early seventeenth century. The telescope was first mentioned in Chinese writing by Emanuel Diaz (Yang MaNuo), who wrote his Tian Wen Le in 1615.[31] In 1626, Johann Adam Schall von Bell (Tang Ruowang) published the Chinese treatise on the telescope known as the Yuan Jing Shuo (The Far-Seeing Optic Glass).[32] The Chongzhen Emperor (, r. 16271644) of the Ming dynasty acquired the telescope of Johannes Terrentius (or Johann Schreck; Deng Yu-han) in 1634, ten years before the collapse of the Ming Dynasty.[31] However, the impact on Chinese astronomy was limited.

The Jesuit China missions of the sixteenth and seventeenth centuries brought Western astronomy, then undergoing its own revolution, to China. After the Galileo affair early in the seventeenth century, the Roman Catholic Jesuit order was required to adhere to geocentrism and ignore the heliocentric teachings of Copernicus and his followers, even though they were becoming standard in European astronomy.[33] Thus, the Jesuits initially shared an Earth-centered and largely pre-Copernican astronomy with their Chinese hosts (i.e., the Ptolemaic-Aristotelian views from Hellenistic times).[33] The Jesuits (such as Giacomo Rho) later introduced Tycho's geoheliocentric model as the standard cosmological model.[34] The Chinese often were fundamentally opposed to this as well, since the Chinese had long believed (from the ancient doctrine of Xuan Ye) that the celestial bodies floated in a void of infinite space.[33] This contradicted the Aristotelian view of solid concentric crystalline spheres, where there was not a void, but a mass of air between the heavenly bodies.[33]

Of course, the views of Copernicus, Galileo, and Tycho Brahe would eventually triumph in European science, and these ideas slowly leaked into China despite Jesuit efforts to curb them in the beginning. In 1627, the Polish Jesuit Michael Boym (Bu Mige) introduced Johannes Kepler's Copernican Rudolphine Tables with much enthusiasm to the Ming court at Beijing.[31] In Adam Schall von Bell's Chinese-written treatise of Western astronomy in 1640, the names of Copernicus (Ge-Bai-Ni), Galileo (Jia-li-le), and Tycho Brahe (Di-gu) were formally introduced to China.[35] There were also Jesuits in China who were in favor of the Copernican theory, such as Nicholas Smogulecki and Wenceslaus Kirwitzer.[31] However, Copernican views were not widespread or wholly accepted in China during this time.

Ferdinand Augustin Hallerstein (Liu Songling) created the first spherical astrolabe as the Head of the Imperial Astronomical Bureau from 1739 until 1774. The former Beijing Astronomical observatory, now a museum, still hosts the armillary sphere with rotating rings, which was made under Hallersteins leadership and is considered the most prominent astronomical instrument.

While in Japan, the Dutch aided the Japanese with the first modern observatory of Japan in 1725, headed by Nakane Genkei, whose observatory of astronomers wholly accepted the Copernican view.[36] In contrast, the Copernican view was not accepted in mainstream China until the early nineteenth century, with the Protestant missionaries such as Joseph Edkins, Alex Wylie, and John Fryer.[36]

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Chinese astronomy - Wikipedia

Rosliston Astronomy Group hit observatory fund-raising target of 20000 – Burton Mail

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A new community-use observatory will be built this summer after a South Derbyshire astronomy group hit their fund-raising target. Rosliston Astronomy Group have been working tirelessly to raise the 20,000 needed to build the new observatory that will allow people young and old to discover the wonders of the universe.

Already boosted by a 10,000 grant from the South Derbyshire Community Partnership Fund, the amateur astronomers just needed to raise the other half and have now achieved their goal.

All this means that work can begin in earnest within the grounds of Rosliston Forestry Centre as early as this summer. Astronomy group treasurer Heather Lomas said she was "thrilled" that they had hit their target.

Members plan to invite schools, groups and individuals to visit the new centre to learn about and explore the universe.

The new observatory will make the stars and the universe accessible to the community

Mrs Lomas said: "It's a huge relief to get to the target and we're hugely grateful for all the support that we've received.

"Gaining the last few thousand pounds was tough but Derbyshire County Council helped us out with the last bit and now it's all systems go. We're hoping that building can begin in either June or July and it will be a great facility for us to share with the community, the elderly, local schools and other community groups."

Events like an astronomical talk hosted by Professor Ian Morison at the Pirelli Stadium were key in helping the group to reach their fund-raising total.

The site for the new observatory is in a 'dark sky' part of Rosliston Forestry Centre meaning it should provide a great view of the stars and beyond. Mrs Lomas believes the venue will be a "huge asset" to the area and will allow the group to inspire and educate people from South Derbyshire and beyond.

She added: "We are still looking to raise more funds the money we have will pay for the building, but now we're looking towards getting new equipment for inside. "We want to be able to share what we have with the community and really inspire people and help them to enjoy the night sky."

Anyone who would like to support the project further can contact Mrs Lomas by email at hlbluelilac@googlemail.com

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Rosliston Astronomy Group hit observatory fund-raising target of 20000 - Burton Mail

Astronomy Cast Ep. 443: Destroy and Rebuild Pt. 7: Tsunamis … – Universe Today


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Astronomy Cast Ep. 443: Destroy and Rebuild Pt. 7: Tsunamis ...
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Surf's up! Today we're going to be talking about one of the most devastating natural disasters out there: tsunamis. We're talking huge waves that wreck the.

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Astronomy Cast Ep. 443: Destroy and Rebuild Pt. 7: Tsunamis ... - Universe Today

Smithsonian Air & Space Magazine features Clancy teacher’s astronomy photos – Helena Independent Record

This week, the Smithsonian's Air & Space Magazine features the night sky astronomy photos of Clancy School science teacher Ryan Hannahoe.

Clancy School science teacher Ryan Hannahoe

Hannahoe, who is also director of the Montana Learning Center at Canyon Ferry Lake, got hooked on gazing at the night sky as a kid and built a telescope while a student at Schuylkill Valley Middle School in Leesport, Pennsylvania.

He and the telescope won the Astronomy Award at the Regional Science & Engineering Fair in Reading, Pennsylvania.

During college at Montana State University, Hannahoe spent the summer working at the NASA Goddard Space Flight Center teaching others about the James Webb Space Telescope, the successor of the Hubble telescope. Its launch date is set for October 2018.

In MSU news articles, Hannahoe said it will allow scientists to see to the beginning of the universe... how galaxies formed.

For some of the photos featured this week, Hannahoe took 30 to 50 hours of exposures and then layered them on top of each other to give a clear image.

All the photos Im posting are all taken remotely from either an Australian or New Mexico site, he said. Hes been doing digital astrophotography since 2001.

This is the second time Hannahoe's photos are featured in the Smithsonian's Air & Space Magazine. The first time was in 2011. He's also had three NASA astronomy pictures of the day.

The photos are posted March 6-12, with three to four featured daily. The posting also contains a log of all the images.

Other astronomy-related projects hes doing include building an observatory at his house and chasing down the total solar eclipse this August, probably in Rexburg, Idaho.

A total solar eclipse is a once-in-a-lifetime event," he said. "We haven't had a total solar eclipse in this part of the country since 1979."

Considered one of the most photographed objects in the sky, the Horsehead Nebula resides 1,500 light-years from Earth in the constellation of Orion. This dark nebula represents a cloud of dust and non-luminous gas that appears to represent a horses head. Williamina Fleming, one of the most renowned female astronomers ever, became the first person to observe the horse head-like structure on a photographic plate.

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Smithsonian Air & Space Magazine features Clancy teacher's astronomy photos - Helena Independent Record

No, aliens haven’t invaded Saturn: It’s Pan, the flying saucer moon! – Blastr

[Credit: NASA/JPL-Caltech/Space Science Institute]

The Cassini spacecraft never fails to amaze. Even after 13 years of orbiting Saturn, it can still send back images to Earth that stun. Want proof? Check out this astonishing picture of Saturns moon Pan:

What the what? We knew it was weirdly shaped from earlier images maybe like a walnut or a flying saucer but these new ones are still shocking. Look at it: It has a ridge along its equator thats several kilometers high! Heck, its not a ridge, its a brim.

Except its not. Its more like a sand dune. Made of ice. An ice dune. An ice dune that circles the moon.

OK, enough teasing. Heres whats what:

Pan is a wee little thing as moons go, only about 35 kilometers across its long axis. It actually is rather walnut-shaped, and it orbits Saturn inside the A ring, the brightest of the planets main rings. Theres a gap in the ring, called the Encke Gap, and Pan orbits right in the center of the gap. Thats no coincidence: The gravity of the moon, though feeble, is enough to clear out ice particles in the ring, carving the 325-km-wide gap.

In 1985, astronomers predicted there was a moon in the Encke Gap because the edges of the gap were seen to be wavy in Voyager probe images. A moon on a very slightly eccentric (non-circular) or tilted orbit could cause ripples like that, and sure enough, Pan was discovered in 1990 by an astronomer looking at old Voyager 1 images from 1981. Pans orbit is not tilted, but it is very slightly elliptical. As it moves closer to one edge of the gap or the other, it draws up waves in the particles (this phenomenon was recently seen in jaw-dropping detail when Cassini looked at the tiny moon Daphnis).

More recent Cassini images taken from a long distance showed Pan to be weird. These new, much higher-resolution images we see now are thanks to Cassinis new orbit, which takes it over the poles of Saturn and then diving down to just outside the main rings. This brings the spacecraft closer to the moons embedded in the rings, allowing us to get far more detailed shots. This is the closest Cassini has ever been to Pan, and these are the best images humans have ever seen of it.

Because Pan orbits inside the rings, it can gravitationally attract the tiny ice particles that make up the rings, and pull them onto its surface. Now, despite being hundreds of thousands of kilometers wide, the rings of Saturn are incredibly thin, in places only just 10 meters thick! Thats the height of a two-story house*, for some perspective.

Because Pan orbits exactly in the plane of the rings, when it pulls in the ice the particles land on its equator, all around the moon. This stuff piles up. On Earth, this would make on low, long ridge, because Earths gravity is strong, and the particles would slump if they piled up past a certain height.

But Pans gravity is very weak, just one-ten thousandth as strong as Earths. You could easily throw a baseball off the surface and have it leave the moon forever. Because of that teeny force, the ring particles can pile up to tremendous height without slumping. The result is a slightly triangular wall that reaches more than seven kilometers off the surface in some places! Thats higher than any Rocky Mountain, and yet it presents a nearly vertical face. Its a continuous, sinuous cliff as tall as a mountain ringing (haha) the moon.

Interestingly, you can see a few craters in the ridge. That surprised me; Id expect it to be very fragile. Perhaps very low speed collisions with bigger objects carved out those impact craters. I expect scientists will be able to use these craters to estimate how compacted the ridge is, and how well the ring particles adhere to each other. At the top left, you can see a bright streak along the top of the ridge; Im guessing thats from the particles slipping, causing a minor slide of material.

The moon, itself, shows some of that, too. Im no planetary scientist, but there are some obvious conclusions to draw with an experienced eye. There are very few craters, indicating the surface is young if it were old, wed see lots of craters from impacts over time. This strongly implies that the entire surface of the moon has a layer of ice or dust on it, falling slowly from Saturns environment. Those long steps you can see criss-crossing it are probably where the material has slipped: moonslides.

What a sight that would be to see in action! In that low gravity, such a slide would take a long time to play out, like watching an avalanche in slow motion. [Update (March 10, 2017 at 16:30 UTC): It just occured to me that the moon may be covered in smaller particles due to material on the ridge sliding down. It seems obvious in retrospect, and my apologies for not thinking of it when I inititally wrote this post!]

By the way, Pan isnt alone. Another moonlet, Atlas, shows the same sort of very tall ridge, making them both look like Klaatus spaceship. In that image, you can actually see that Atlas appears to be buried under ring particles even more than Pan is.

If youre wondering why were only getting these close-ups of Pan now, after 13 years of Saturn-gazing, its because the Cassini mission is coming to an end. Its running out of fuel to make maneuvers, and the engineers dont want it to accidentally impact a moon and contaminate it. So, in September they will command it to drop into the atmosphere of Saturn, itself, sending back data as it plunges to its death.

Thats bittersweet, to be sure, but it also allows the Cassini team to take more risks, including setting up these ring-diving orbits. Over the next few months well be seeing more spectacular images like these, and I have to admit it brings me some cheer. After all these years of sending back wonders from a billion kilometers away, Cassini is going out in an orgy of observations, and well reap the benefits of its demise.

Correction (March 10, 2017 at 16:50 UTC): I originally wrote that ten meters is a one-story house, but it's more like two if you include a peaked roof.

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No, aliens haven't invaded Saturn: It's Pan, the flying saucer moon! - Blastr

Hubble solves the mystery bulge at the center of the Milky Way – Astronomy Magazine

The Milky Way appears as a relatively flat structure when viewed along its plane in visible light. Gamma-ray emission, however, paints a different picture: two huge structures billowing outward from the galaxys bulge like an enormous hourglass. Named the Fermi Bubbles, these structures are the result of the Milky Ways supermassive black hole gorging itself on interstellar gas in the past. Using the Hubble Space Telescope (HST), astronomers have now determined just when these structured formed.

A team of astronomers led by Rongmon Bordoloi of the Massachusetts Institute of Technology has used distant quasars to trace the structure and motion of the northern Fermi Bubble, which rises 23,000 light-years above the plane of the Milky Way and contains enough cool gas to create 2 million Sun-size stars. By observing the ultraviolet light from 46 quasars with the Cosmic Origins Spectrograph (COS) on HST (and adding one quasar observation with HSTs Space Telescope Imaging Spectrograph), the team mapped out the motions of cool gas within the bubble to pin down its age: 6 to 9 million years.

Most galaxies contain a supermassive black hole at the center, and our Milky Way is no exception. Sgr A* resides in the Milky Ways bulge and has a mass equivalent to 4.5 million solar masses. Today, Sgr A* is relatively quiet, accreting slowly as the galaxy ages. By contrast, quasars are young, massive supermassive black holes at the centers of galaxies in the early universe, sucking down huge amounts of gas and dust that shine brightly as the material is funneled into an accretion disk before finally passing into the black hole. Like these younger black holes, astronomers believe that our own supermassive black hole was once more active, at a time when the galaxy was still forming and material was more plentiful for accretion.

Sometimes, though, material doesnt actually make it all the way into the black hole. Matter can escape along the black holes spin axis, exiting the area and often the galaxy altogether as huge outflows that span tens or hundreds of thousands of light-years. The Milky Ways Fermi Bubbles are such an outflow; they were discovered in 2015 and named after NASAs Fermi Gamma-Ray Telescope, which spotted them.

Learning more about the origins of these outflows requires information about their motion. We have traced the outflows of other galaxies, but we have never been able to actually map the motion of the gas, said Bordoloi in a press release announcing his groups results. The work also appeared in the January 10, 2017 edition of The Astrophysical Journal. The only reason we could do it here is because we are inside the Milky Way. This vantage point gives us a front-row seat to map out the kinematic structure of the Milky Way outflow.

As the quasars light travels through the bubble to reach Earth, it highlights the gas in bubble itself, allowing astronomers to determine information such as its chemical composition, temperature, and motion. The cool gas in the northern Fermi Bubble, which contains elements such as silicon and carbon, was clocked at 2 million miles per hour (3 million kph) an reaches temperatures of 17,700 degrees Fahrenheit (9,800 degrees Celsius).

Such cool gas is actually likely gas from the disk of the galaxy that has been swept up by and integrated into the outflow itself, which has temperatures of up to 18 million degrees F (nearly 10 million degrees C). It is these high temperatures that cause the gas to shine in energetic light, such as gamma rays.

Once the gas motion its direction of movement and velocity was measured, astronomers used this data to turn back the clock and pinpoint when the gas started moving. This origin is also the last known big meal enjoyed by Sgr A*, which hasnt managed to suck down such a significant amount of matter ever since.

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Hubble solves the mystery bulge at the center of the Milky Way - Astronomy Magazine

Seeing the Treasures of Messier’s List with Mobile Astronomy Apps – Space.com

The March evening sky features many of the beautiful objects in the Messier List, a catalog of "nuisance objects" compiled by comet hunter Charles Messier in the late 1700s. His first object, M1, is the Crab Nebula, the faint remnant of a star that exploded in a supernova that was visible in daylight in 1054. Your astronomy app can help you find it.

If you spend any time with astronomers, sooner or later, you'll hear them use the phrase "M" something or other such as "M42" or "M31." They are referencing deep-sky objects from a list that was compiled by French astronomer Charles Messier during the 1770s. Messier was a lifelong comet hunter. On clear, moonless evenings, he swept the dark skies over Paris, looking for their telltale fuzzy smudges.

Unfortunately for him, his searches frequently turned up objects that were comet-like in appearance, but altogether different nebulas, star clusters and distant galaxies whose true natures were unknown at the time. To avoid being fooled again by these "nuisances," he recorded their appearance and location, and shared the information with fellow comet chasers.

With help from Messier's contemporaries, the list grew into a veritable treasure trove of celestial treats for amateur astronomers. All of them are observable with backyard telescopes and binoculars under dark skies, and quite a few are visible with unaided eyes. In this edition of Mobile Astronomy, we'll focus on the Messier List and how you can see the objects yourself and learn more about them with the help of your favorite astronomy app. We'll even tell you how to spot all 110 of them in a single night! [Messier 47: Blue Stars Sparkle in Spectacular Deep Space Star Cluster]

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Every year, new comets appear in the sky, and they brighten as their gas and dust are released by the warmth of the sun as they enter the inner solar system from the frigid realm beyond Neptune's orbit. They appear as fuzzy, glowing objects that move across the sky against the distant, fixed stars. Discovering a new comet has always been a prestigious honor, and doing so brings fame and accolades from fellow astronomers not to mention the honor of having one's name immortalized! Canadian astronomer David Levy has discovered almost two dozen comets and continues to search from his home in Arizona. On the other side of the globe, prolific amateur astronomer Terry Lovejoy of Queensland, Australia, has discovered five.

It's becoming harder for amateur astronomers to beat the modern automated comet-hunting telescopes, but that was not so in early days of telescope astronomy. In 1705, Edmond Halley calculated that the bright comet that now bears his name would return around 1758, and the chase was on to be the first person to spot it. Messier was a junior astronomer working at the Marine Observatory at the Hotel de Cluny in Paris. In mid-1757, he began searching for the comet in the areas they were most likely to be the sky. On Jan. 21, 1759, he saw it but he was second to a German amateur astronomer, who had glimpsed it a few weeks beforehand.

Still, Messier was hooked. He continued searching for comets by sweeping the skies on clear, moonless nights. His 4-inch-aperture (100 mm) telescope was only slightly larger than most beginner telescopes in use today. The sky was still largely uncharted then, except for the prominent stars labeled on the published paper atlases. On Aug. 28, 1758, he spotted a possible comet in the constellation Taurus, but it didn't move from night to night. He decided to catalog these uncharted imposters, starting with this first object, which we now know as the Crab Nebula, or Messier 1.

Charles Messier (1730-1817) compiled his catalog of uncharted comet-like "nebulas" between 1758 and 1781. The French Academy of Sciences published the list for the benefit of the comet hunters of the day, but modern amateur astronomers delight in its treasures. The first page of the third edition, showing Messier 1 through 5, is presented on the right.

In 1771, after compiling 45 objects with descriptive notes and coordinates, Messier submitted the list to the French Academy of Sciences, and it was published in 1774. Some objects were contributed by Messier, and the rest were added by his contemporaries Pierre Mchain, Barnabus Oriani and Nicolas Louis de Lacaille. Their final list, published in 1784, contained 103 objects. Between 1947 and 1967, seven more objects were added by astronomers Helen Sawyer Hogg, Owen Gingerich and Kenneth Glyn Jones on the basis that they were mentioned in Messier's notes but that he either forgot them or had planned to add them later.

Virtually every astronomy sky-charting app will include the 110 objects, referring to them collectively as the Messier List or the Messier Catalog. The objects will be designated by their "M-codes" M1 through M110 (or Messier 1 through Messier 110). Amateur astronomers refer to the group as the Messiers. Because they are so famous, most of the objects also have proper names, like the Whirlpool Galaxy, the Pleiades and the Beehive Cluster. They run the gamut of deep-sky objects. Let's take a look at what's inside. [Spectacular Photos of Nebulas in Deep Space]

All but two items in the Messier List are deep-sky objects a label that covers any celestial object outside our solar system that isn't an individual star or small multiple-star system. Broken down by type, the list contains 40 galaxies, 57 star clusters, nine nebulas, the Crab Nebula supernova remnant, a rich patch of Milky Way stars, a double star and a star grouping. It's not clear why Messier chose to include the last two non-deep-sky objects, why he included some that would never have been confused with a comet or why he left out some other great objects. Let's describe what the object types are and where they typically occur in the sky.

A gallery of all 110 deep-sky objects in the Messier List, starting with Messier 1 at upper left. The collection includes a sampling of nearly every type of deep-sky object, including galaxies, nebulas, and star clusters.

To put things into context, the Milky Way is the band of light that stretches across the night sky. It represents the flattened disk of our home galaxy projected onto the sky. Open clusters are irregular knots containing dozens to thousands of stars that populate the spiral arms that form the plane of our galaxy. In the night sky, most of them are located within or near the Milky Way, and some have nebulosity surrounding them. Globular clusters are spherical collections of up to a million very old stars. These ancient clusters orbit our galaxy's core like swarms of bees, so they are generally located away from the Milky Way.

Nebulas are concentrations of gas in our galactic plane. They come in four types. Emission nebulas are composed of ionized hydrogen gas glowing with a pinkish light triggered by radiation from nearby stars. Reflection nebulasDark nebulas are dense clouds of interstellar dust that obscure the stars beyond them they look like a hole in space. And planetary nebulas are the spherical corpses of sun-like stars that have ejected their outer shells. The white dwarf star in their center makes the gases glow. These spectacular objects have dim, planet-like disks, and exhibit a variety of colors and internal structures. They can be found anywhere in the sky, but there are more near the plane of the galaxy where most of the galaxy's stars are.

Distant galaxies are distributed all over the sky, but we cannot observe the ones hidden behind the stars, gas and dust of our own galaxy. As a result, the Messier List galaxies are mainly located away from the plane of the Milky Way. They come in shapes ranging from featureless ellipsoids to flat disks surrounded by well-defined, curving spiral arms. When the galaxy is oriented edge-on to our line of sight (or close to it), all of its light is concentrated into a smaller area of the sky, making it appear brighter. Some galaxies feature dark dust rims that divide them in two. Galaxies that are oriented face-on to Earth are generally much dimmer, but they cover a larger area of sky and are among the most spectacular. [Galactic Evolution: How Galaxies Are Classified by Type (Infographic)]

Messier 1, also called the Crab Nebula, is none of the above. The Crab Nebula, located in the constellation Taurus, is the still-expanding remnant of a massive star that ended its life in a spectacular supernova explosion. The light from the event reached Earth on July 4, 1054, and it was so bright that it could be seen in daylight for many days, and then as a bright nighttime object for several years all chronicled by Chinese astronomers who observed it at the time. By Messier's era, the object would have been much dimmer and would have looked very comet-like. Now, 250 years later, it has dimmed further and is one of the toughest Messiers to see.

For four of the objects M47, M48, M91 and M102 modern astronomers failed to find anything comet-like where Messier indicated. Most of the missing objects have been explained as transcription errors, and the actual objects are located in different areas. Your astronomy app will have the complete corrected set.

Part of the fun of enjoying the Messier objects is sketching and imaging them. At left is Charles Messier's original drawing of the Orion Nebula, Messier 42. On the right is an image taken through a telescope using a DLSR camera by Rick Foster of Markham, Ontario.

On any given evening, at least some of the Messier List objects are observable from mid-northern latitudes. Many of them can be seen with unaided eyes, but magnification aids viewing for all of them. In fact, several of the objects cover too much sky for a telescope's narrow field of view. For these objects, binoculars of any size work best.

Many of the objects are dim, so you'll want to search for them on a moonless night, away from artificial lights. To preserve your eyes' sensitivity to dim light, turn your device's screen brightness to minimum, and enable the red-screen mode in the app. Better still, buy some red film and cut it to cover your device's screen. That way, phone calls or notifications won't pop up with bright white light. Messier 31, also known as the Andromeda Galaxy, is six moon diameters across from our viewpoint on Earth. It's brighter in the center and dims toward the edges. As your eyes adjust to the darkness, you'll see more of it.

When you open the search menu in SkySafari 5, the Messier List objects are included for you. The objects visible in your sky are bolded. If you sort the list by Visual Magnitude, the objects that are brightest and easiest to see will be listed first. In your astronomy app's sky chart, the deep-sky objects will use coded symbols representing the different object types.

Your astronomy app should contain the Messier objects under a separate listing. In addition to the Messier designation, the app will give the proper name and an NGC (New General Catalog) number. The NGC is the master catalog of 7,840 deep-sky objects covering the entire sky.

In the SkySafari 5 app, open the Search menu, and scroll to Messier Objects. The ones currently in the sky are bolded, so use the time control panel to ensure that the app is set to the time you are observing. By default, the display order is by Catalog Number, but I recommend switching to Visual Magnitude, which will bring the easier-to-see objects to the top of the list. If you wish to see where they are in the sky, tap the Settings and enable Highlight Objects. When you exit the Search menu, blue circles will be drawn around every Messier object. You might be surprised by how many there are!

To get you started, here are some Messier objects for each type of deep-sky object. Your app will contain a complete description of each object. Just like the constellations, Messier objects return annually during the same season. Be sure to check the app every now and again to see which new objects are visible during the course of the year.

M1 (Crab Nebula), faint supernova remnant in Taurus; telescope

M13 (Hercules Cluster), bright globular cluster in Hercules; binoculars/telescope

M31 (Andromeda Galaxy), spiral galaxy in Andromeda; naked eye/binoculars

M42 (Orion Nebula), emission/reflection nebula in Orion; binoculars

M45 (The Pleiades), open cluster in Taurus; naked eye/binoculars

M57 (Ring Nebula), planetary nebula in Lyra (rises before midnight); telescope

The SkySafari 5 app can display circles around classes of objects, including all the Messiers. This image shows the evening sky at 8 p.m. on March 27, 2017, the last evening of Messier Marathon season, when all 110 objects can be viewed in a single night. To do the marathon, you will need to observe the galaxies Messier 74 and Messier 77 (aka, Cetus A) first, before they set.

Take your time to enjoy each object. Take long looks, to tease out details. And remember to breathe your eyes function better when oxygenated. Many people enjoy sketching the objects with a pencil and paper, or photographing them through the eyepiece. If you gain access to stronger binoculars or a larger telescope in the future, take another look. More details and colors will be revealed. After you come back inside, look at the high-resolution color images available in the app or online, to get a better appreciation for what you saw. If you're hooked on Messiers, there are plenty of free apps devoted to them the images make terrific home screens!

In his list, Messier included only the objects that he could see from France, and only the ones bright enough for his modest telescope to see. There are dozens of objects seen only from the southern latitudes that certainly would have qualified for inclusion, had he been in the right location to look. In December 1995, English astronomer Sir Patrick Moore published his own list of 109 additional objects called the Caldwell List (his middle name). It encompasses the entire sky, with the objects in numerical order, from the north celestial pole to the south.

By the end of his life, Messier had discovered 15 comets, 12 bearing his name. His comets are long gone, but the objects in his list of "nuisances" are spectacular showpieces for stargazers, and a perfect way for beginners to sample the best of the night sky. Here's hoping you are inspired to take advantage of his efforts and enjoy his legacy for yourself.

As it happens, early spring ;is the only time of the year when its possible to observe every object in the Messier List in a single night from dusk to dawn. Astronomers call this challenge the Messier Marathon. To allow for seeing the fainter objects, pick a moonless evening on, or just before, the new moon (this year its March 27) and check for clear weather all night. Fuel up with snacks and drinks youll be awake all night! Pick a site free from lights with open sightlines. You can use your app to preview where the objects will be at different times through the night. (Heres a website with some tips.)

First, you'll need to catch the objects that set in the west after sunset, including M77 and M74. Then, you can work your way across the sky from west to east. As you do so, more objects will rise in the east. As dawn starts to break around 6 a.m., the last object, M30, will rise in the east, so it might be difficult to see. Part of the trick is to be organized and efficient. Check this site for a recommended viewing order.

The Messier Marathon is a rite of passage for astronomers, but not everyone is a fan. Astronomy author Stephen James O'Meara likens it to sprinting through the Louvre, glimpsing the paintings. Some skywatchers use computerized GoTo telescopes to make it easier, while a few seasoned pros can find the objects manually! It will likely take you several attempts. I wish you luck!

In a future edition of Mobile Stargazing, we'll dive into the Caldwell List objects. In the meantime, keep looking up!

Editor's note: Chris Vaughan is an astronomy public outreach and education specialist, and operator of the historic 1.88-meter David Dunlap Observatory telescope. You can reach him via email, and follow him on Twitter as @astrogeoguy, as well as on Facebook and Tumblr.

This article was provided by Simulation Curriculum, the leader in space science curriculum solutions and the makers of the SkySafari app for Android and iOS. Follow SkySafari on Twitter @SkySafariAstro. Follow us @Spacedotcom, Facebook and Google+. Original article onSpace.com.

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Seeing the Treasures of Messier's List with Mobile Astronomy Apps - Space.com

SARAH WILD: SA’s astronomy centres to become one constellation – Business Day (registration)

Vodafone donated a 32m dish outside Accra to the Ghanaian government for radio astronomy.

A major impetus for the African VLBI Network is to develop radio astronomers and engineers in African countries, particularly the eight African SKA partner countries that are scheduled to house small SKA sites of their own.

"If youre sitting with a birds eye view [of radio astronomy projects] in the Department of Science and Technology, it makes sense. It makes no sense to have initiatives dotted around," says Adam.

However, there were concerns over the absorption of HartRAO into SKA SA, even though they will both be included into the SARAO.

HartRAO began life in 1961 as the US National Aeronautics and Space Administrations Deep Space Station 51 and was instrumental in tracking probes outside Earths orbit. It specialises in VLBI and a type of science called geodesy, which measures various aspects of Earth, such as continental drift or its distance from the moon.

"As with any merger, there would be concerns. These we have addressed through constructive dialogue during the merger process," says Prof Ludwig Combrinck, acting MD at HartRAO.

These sentiments were echoed by Adam and Chetty, who say the countrys geodesy specialisation will be maintained and preserved.

"With there being a strong political imperative to grow astronomy broadly in SA, not just in the Western Cape and Northern Cape, the location of HartRAO in Gauteng ensures that it has a unique role to play," says Chetty.

He says HartRAO is crucial for training, especially African partner country training.

Initially, the SKA SA was driven from within HartRAO, but eventually became too large to be contained by the small radio astronomy facility.

This amalgamation shows how sprawling radio astronomy has become in SA. From a single dish in the hills of Hartebeesthoek, about an hours drive from Pretoria, radio astronomy is attracting scientists and students from all over the world.

This high-technology scientific discipline now employs hundreds of people across the country, trains students inside and outside SA and is responsible for building infrastructure worth billions of rand.

"The setting up of SARAO indicates the transitioning of SKA SA from an engineering project to a scientific institution, an astronomy observatory," says Chetty.

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SARAH WILD: SA's astronomy centres to become one constellation - Business Day (registration)

Ancient stardust sheds light on the first stars – Astronomy Now Online

This artists impression shows what the very distant young galaxy A2744_YD4 might look like. Observations using ALMA have shown that this galaxy, seen when the Universe was just 4% of its current age, is rich in dust. Such dust was produced by an earlier generation of stars and these observations provide insights into the birth and explosive deaths of the very first stars in the Universe. Credit: ESO/M. Kornmesser

Astronomers have used ALMA to detect a huge mass of glowing stardust in a galaxy seen when the Universe was only four percent of its present age. This galaxy was observed shortly after its formation and is the most distant galaxy in which dust has been detected. This observation is also the most distant detection of oxygen in the Universe. These new results provide brand-new insights into the birth and explosive deaths of the very first stars.

An international team of astronomers, led by Nicolas Laporte of University College London, have used theAtacama Large Millimeter/submillimeter Array(ALMA) to observe A2744_YD4, the youngest and most remote galaxy ever seen by ALMA. They were surprised to find that this youthful galaxy contained an abundance of interstellar dust dust formed by the deaths of an earlier generation of stars.

Follow-up observations using the X-shooterinstrument on ESOs Very Large Telescopeconfirmed the enormous distance to A2744_YD4. The galaxy appears to us as it was when the Universe was only 600 million years old, during the period when the first stars and galaxies were forming.

Not only is A2744_YD4 the most distant galaxy yet observed by ALMA, comments Nicolas Laporte, but the detection of so much dust indicates early supernovae must have already polluted this galaxy.

Cosmic dust is mainly composed of silicon, carbon and aluminium, in grains as small as a millionth of a centimetre across. The chemical elements in these grains are forged inside stars and are scattered across the cosmos when the stars die, most spectacularly in supernova explosions, the final fate of short-lived, massive stars. Today, this dust is plentiful and is a key building block in the formation of stars, planets and complex molecules; but in the early Universe before the first generations of stars died out it was scarce.

The observations of the dusty galaxy A2744_YD4 were made possible because this galaxy lies behind a massive galaxy cluster called Abell 2744. Because of a phenomenon called gravitational lensing, the cluster acted like a giant cosmic telescope to magnify the more distant A2744_YD4 by about 1.8 times, allowing the team to peer far back into the early Universe.

The ALMA observations also detected the glowing emission of ionised oxygen from A2744_YD4. This is the most distant, and hence earliest, detection of oxygen in the Universe, surpassing another ALMA resultfrom 2016.

The detection of dust in the early Universe provides new information on when the first supernovae exploded and hence the time when the first hot stars bathed the Universe in light. Determining the timing of this cosmic dawn is one of the holy grails of modern astronomy, and it can be indirectly probed through the study of early interstellar dust.

The team estimates that A2744_YD4 contained an amount of dust equivalent to 6 million times the mass of our Sun, while the galaxys total stellar mass the mass of all its stars was 2 billion times the mass of our Sun. The team also measured the rate of star formation in A2744_YD4 and found that stars are forming at a rate of 20 solar masses per year compared to just one solar mass per year in the Milky Way.

This rate is not unusual for such a distant galaxy, but it does shed light on how quickly the dust in A2744_YD4 formed, explains Richard Ellis (ESO and University College London), a co-author of the study. Remarkably, the required time is only about 200 million years so we are witnessing this galaxy shortly after its formation.

This means that significant star formation began approximately 200 million years before the epoch at which the galaxy is being observed. This provides a great opportunity for ALMA to help study the era when the first stars and galaxies switched on the earliest epoch yet probed. Our Sun, our planet and our existence are the products 13 billion years later of this first generation of stars. By studying their formation, lives and deaths, we are exploring our origins.

With ALMA, the prospects for performing deeper and more extensive observations of similar galaxies at these early times are very promising, says Ellis.

And Laporte concludes: Further measurements of this kind offer the exciting prospect of tracing early star formation and the creation of the heavier chemical elements even further back into the early Universe.

Continued here:

Ancient stardust sheds light on the first stars - Astronomy Now Online

If we assume global warming is a hoax, what should we expect to see? – Blastr

[Credit: Shutterstock/boscorelli]

I will ask you to indulge me for a moment in a thought experiment. Its not hard, and it leads to a startlingly simple yet powerful conclusion, one I think you may find both important and terribly useful.

Still, it starts with a big ask, so forgive me. And that is: Lets make an assumption, one youve heard many times before. Lets say that global warming is a hoax.

I know, I know. But go with this, here. So, yes, lets say that climate change deniers people like House Science, Space, and Technology Committee chairman Lamar Smith, Senator James Inhofe, and even Donald Trumphimself are right. Whatever the reasons (Chinese hoax, climatologist cabal clamoring colossal cash, carbon dioxide isnt a powerful greenhouse gas, or just a liberal conspiracy), lets say that the Earth is not warming up.

In that case, the temperatures we see today on average should be much like the ones we saw, say, 20 years ago. Or 50. Sure, youd see fluctuations. In a given spot on a given day the temperature in 1968 might have been a degree warmer than it was in 1974, or three degrees cooler than in 2010. But what youd expect is that over time, a graph showing the temperature would be pretty much flat, with lots of short-term spikes up and down.

Now, statistically speaking, you expect some records to be broken every now and again. Over time, every few years for a given day youd get a record high, and every few years a record low. The details will change from place to place and time to time, but again, if the average temperature trend is flat, unchanging, then you would expect to see just as many record cold days as record warm days. There might be small deviations, like, say, a handful of more cool than warm days, but the difference would be very small depending on how many days you look at.

Its like flipping a coin. On average, you should get a 50/50 split between heads and tails. But if you flip it 10 times, say, you wouldnt be shocked to see seven heads and three tails. But if you flip it a thousand times, youd really expect to see a very even split. Seeing 700 heads and 300 tails would be truly extraordinary.

So, if we remind ourselves of our basic assumption global warming isnt realthen we expect there to be as many record high days as there are record lows. Simple statistics.

So, what do we see?

Guy Walton, a meteorologist in Georgia, took a look at the data from the NOAAs National Centers for Environmental Information. Whenever a weather station in the US breaks a record, high or low, its catalogued (Walton has more info on this at the link above). He found something astonishing: For February 2017, the number of record highs across the US recorded was 6,201.

The number of record lows? 128.

Thats a ratio of over 48:1. In just one month.

Again, if temperatures were flat over time, and record highs and lows were random fluctuations, youd expect a ratio much closer to 1:1. In other words, out of 6329 records set in total, youd expect there to be about 3165 record highs, and 3165 record lows.

For fans of statistics, with a total of 6329 records broken, one standard deviation is the square root of that, or about 80. So, sure, something like 3265 highs and 3064 lows wouldnt be too unusual. If you start to see more of an imbalance than that, it would be weird.

Seeing 6201 record highs to 128 lows is very, very, very weird. Like, zero chance of that happening by accident.

Now, Phil, I can hear you thinking, thats just for the US (2% of the planet) over one month. And youve told us before that weather isnt climate; weather is what you expect now, climate is what you expect over long periods of time. So, maybe this is a fluke?

Walton notes that, if you look at records in the US going back to the 1920s, the six highest ratios of record highs to lows all occur since the 1990s. Huh.

And making this more global, a pair of Australian scientists looked at their countrys data, and found that their ratios were about even...until the 1960s. After that, highs always outnumber lows. From 2000-2014, record highs outnumbered lows there by 12:1.

The University Corporation for Atmospheric Research collated data from 1800 stations across the US and binned the data by decade by decade, which is a huge sample; any deviation from a 1:1 ratio would be extraordinary over that timescale.

They found this:

Huh. Not only are there more record highs than lows, the ratio between the two is getting higher with time.

So, looking back at our initial assumption the Earth isnt warming, and temperatures are flat theres a conclusion these data are screaming at us: That assumption is completely and utterly wrong.

And of course, all the evidence backs this up. All of it. Earths temperature is increasing. Thats because of the 40 billion tons of extra carbon dioxide humans put into the atmosphere every year (the amount we will see this year, expected to top 410 parts per million, has never been seen before in history as long as humans have walked the Earth). This CO2 allows sunlight to warm the Earth, but prevents all of it from escaping so that a little bit of extra heat remains behind, and thats warming our planet.

Over time, were getting hotter. 2014 was a record hot year, beaten by 2015, itself beaten by 2016. In fact, 15 of the 16 hottest years ever recorded have been from 2001 2016. Thats exactly what youd expect if we were getting warmer, and that means our initial assumption of hoaxery was dead wrong.

The science on this is so basic, the evidence of this so overwhelming, that not a single national science academy disputes or denies the scientific consensus around human-caused climate change, and also the overwhelming majority of scientists who study climate do, too.

Maybe you should listen to them, and not politicians who seem ideologically opposed to the science.

Or, you could flip a coin. But if it comes up science dozens of times more often than anti-science, well and forgive me if I sound like a broken record the conclusion is obvious.

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If we assume global warming is a hoax, what should we expect to see? - Blastr

Kepler provides more information about TRAPPIST-1 – Astronomy Magazine

Earlier this month, a team including the European Southern Observatory and NASAs Spitzer telescope team announced that the previously-discovered TRAPPIST-1 hosts seven potentially habitable Earth-size planets. (It was once thought to only have three.)

As it turns out, NASAs Kepler space telescope has also been observing TRAPPIST-1 since December 2016 and now that data is available.

Kepler studied the dwarf stars change in brightness due to transitioning planets for 74 days during a period known as the K2 Campaign 12. That research period gave researchers the longest, near continuous set of observations of the dwarf star yet. The information will help teams look at the planets gravitational interactions as well as continue the search for even more undiscovered planets.

However, Kepler almost missed the opportunity to study TRAPPIST-1. Before news broke in May 2016 about the planets orbiting TRAPPIST-1, Kepler was set to study a different region of space. Once they learned about the planets, though, the teams at NASA and Ball Aerospace & Technologies Corp. worked quickly to rework calculations and commands so the spacecrafts operating system would adjust for Campaign 12 and study the new star system.

In a press release, Michael Haas, science office director for the Kepler and K2 missions at Ames said scientists were excited about the opportunity to study TRAPPIST-1 and had submitted proposals for specific targets of interest in that field.

The unexpected opportunity to further study the TRAPPIST-1 system was quickly recognized and the agility of the K2 team and science community prevailed once again, Haas said.

The K2 mission lasted from December 15, 2016 to March 4, 2017 and provided researchers will information to work with in measuring the planets, working out the orbits, attempting to figure out the mass of the farthest planet, and to learn more about the magnetic activity of TRAPPIST-1.

"Scientists and enthusiasts around the world are invested in learning everything they can about these Earth-size worlds," said Geert Barentsen, K2 research scientist at NASA's Ames Research Center at Moffett Field, California. "Providing the K2 raw data as quickly as possible was a priority to give investigators an early look so they could best define their follow-up research plans. We're thrilled that this will also allow the public to witness the process of discovery."

Any measurement updates and additional discoveries in the K2 data will help astronomers plan for follow-up studies of TRAPPIST-1 world using NASAs James Webb Space Telescope.

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Kepler provides more information about TRAPPIST-1 - Astronomy Magazine

Crowdfunded pocket-sized astronomy camera is all set to ship to backers – Mashable


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Crowdfunded pocket-sized astronomy camera is all set to ship to backers
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The Tiny1 from Singapore startup TinyMOS blew through its Indiegogo fundraising campaign in July last year to raise nearly $430,000 over three times its goal. SEE ALSO: Taking underwater photos with your iPhone just got way easier. When we saw an ...

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Crowdfunded pocket-sized astronomy camera is all set to ship to backers - Mashable

This is where stardust comes from – Astronomy Magazine

The Atacama Large Millimeter/submillimeter Array(ALMA)in the Chilean Andes has made several groundbreaking discoveries since it was brought online in 2011. Able to image the sky in millimeter and submillimeter wavelengths, ALMA can spot emission associated with molecular gas and dust, which are cold and can be difficult or impossible to see at other wavelengths. Using this ability, ALMA has identified dust and gas in a galaxy that formed when our universe was only about 4 percent of its current age.

The galaxy is called A2744_YD4, and its the most distant galaxy ever found by ALMA. It sits at a redshift of 8.38, which is associated with a time when the universe was just 600 million years old.

Redshift measures the amount by which a distant objects light is stretched by the expansion of the universe. Objects with a higher redshift are farther away, and thus we are looking at them as they appeared in the past. In the very nearby universe, objects have a redshift of nearly zero; high-redshift objects, such as A2744_YD4 with its redshift of 8.38, are extremely far away (the exact distance depends on the expansion history of the universe). Its also important to note that redshift is not linear redshifts of 0-1 are considered relatively nearby, while redshifts of 8-9 are some of the farthest objects we can currently see as we look back to the very early universe. The cosmic microwave background was produced at a redshift of about 1,000.

A2744_YD4s cosmological timestamp, as given by its redshift, falls within the estimated age range for the Epoch of Reionization, which occurred somewhere around a redshift of 10, when the universe was about 400 million years old. The Epoch of Reionization is when the universes first luminous sources stars, quasars, and galaxies turned on and ionized neutral hydrogen atoms (that is, knocked their electrons away). Neutral hydrogen is opaque to short wavelengths of light, which means that it absorbs these wavelengths easily so the light cannot pass through. As neutral hydrogen throughout the universe was ionized, however, light could finally travel vast distances.

The detection of A2744_YD4 and its properties, which was made by an international team of astronomers led by Nicolas Laporte of University College London, is remarkable for several reasons.

A2744_YD4 is full of dust. In the press release accompanying the announcement, Laporte explained that the detection of so much dust indicates early supernovae must have already polluted this galaxy. Supernovae are the end result of massive stars, which blow away much of their interiors explosively as they die. Among the material blown away is dust, which is made up of elements such as aluminum, silicon, and carbon, and is spread across galaxies by these explosions. This dust is an integral component of todays stars (like our Sun) and the planets surrounding them. In the very early universe, however, this dust was scarce, simply because the process of its creation and dispersion via supernovae hadnt had much time to complete.

But in A2744_YD4, this process has apparently had enough time to progress. A2744_YD4 produces stars at a rate of 20 solar masses per year, which is a full 20 times the rate of our Milky Ways comparatively paltry star formation rate of 1 solar mass per year. Based upon this rate, the group estimated that only about 200 million years were needed to form the dust seen in A2744_YD4.

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This is where stardust comes from - Astronomy Magazine

Pulsars may be churning out small reserves of antimatter – Astronomy Magazine

We live in a universe dominated by normal matter. This wasnt always true right after the Big Bang, in fact, nearly equal amounts of matter and antimatter were created, and then soon afterwards destroyed as they annihilated each other. But because the amounts of matter and antimatter werent exactly equal, this annihilation was unequal, too, and normal matter won out.

There is, however, still a small amount of antimatter in our universe, and there seems to be an unexplained excess of it. The reason for this antimatter surplus has long been sought, and now it seems astronomers may have finally arrived at a conclusion: Its not dark matter responsible for the excess, but plain old pulsars.

The antimatter surplus refers to the fact that a greater number of high-energy anti-electrons, called positrons, than are expected have been detected in space. These detections have been confirmed by several observatories over the past decade, including the Alpha Magnetic Spectrometeron the International Space Station.

Based on our current astrophysical models, the ratio of high-energy positrons to electrons should be tipped significantly in the electrons favor. But observations show that theres an unexpected increase in the ratio of positrons to electrons at energies between about 10 and a few hundred giga-electron volts (GeV).

Astronomers have developed two possible explanations for this excess. One explanation says that dark matter particles (such as weakly interacting massive particles, or WIMPs) randomly annihilating each other could produce positron-electron pairs. Because dark matter accounts for up to 85% of the matter in the entire universe, such interactions could lead to the observed positron excess.

The other explanation isnt as exotic: The excess could be produced by pulsars and their extremely powerful magnetic fields. These magnetic fields accelerate particles around the pulsar to such high energies that they can generate electron-positron pairs, again bumping up the number of positrons counted by observatories.

Now, a team led by Dan Hooper of the Fermi National Accelerator Laboratory has used gamma-ray data from theHigh-Altitude Water Cherenkov Observatory (HAWC) near Puebla, Mexico, to narrow in on the excess positrons source. They set out to determine just how much of the positron excess could be produced by pulsars. In a recent press release, Hooper explained that Before the HAWC observations, we didnt know whether pulsars made up 0.1 percent of the excess or 100 percent.

Using HAWC, the team observed the famous Geminga pulsar and discovered a halo around the stellar remnant that emitted high-energy gamma rays. This halo, they concluded, is produced by high-energy electrons and positrons slamming into and boosting the energy of photons emitted from the pulsar until they appear as gamma rays.

Still, theres another piece to the puzzle. The electrons and positrons responsible for the halo around Geminga would technically be too energetic (tens of thousands of GeV) to explain the range of energies where the positron excess is actually observed (only up to a few hundred GeV). But based on the amount of high-energy electrons and positrons, Hoopers team then calculated the amount of lower-energy positrons that should also be created, which would contribute to the excess.

In science, just one observation is never enough. So Hoopers team repeated the experiment for a second pulsar, B0656+14. They then extrapolated the number of positrons produced to the total number that would be created by the likely thousands of pulsars inhabiting the galaxy.

The result, Hooper says, is that pulsars are the probable cause for much, if not the entirety of the observed excess, rather than the more exotic explanation of dark matter.

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Pulsars may be churning out small reserves of antimatter - Astronomy Magazine

Cross-institutional research in physics and astronomy leads to best undergraduate student paper – Appalachian State University

By Ellen Gwin Burnette

BOONE, N.C.Hunter Stark, an Appalachian State University sophomore communication major from Charlotte, and James Howe, a Southwestern Community College senior and triple major in electronics, computer, and network engineering technology from Miami, Florida, have been awarded the best undergraduate student paper from the North Carolina Section of the American Association of Physics Teachers.

At each meeting of NCS-AAPT, undergraduate student papers are considered for an award, which includes a check for $100. In order to compete for the award, students must provide a presentation on their research. Stark and Howe worked with Appalachian State Universitys Dr. David Sitar, astronomy outreach coordinator, in their partnership. This was a great collaboration between students from different institutions and from different disciplines, said Sitar.

The paper began as a lab assignment in spectroscopy. RSpec, the program around which the assignment centered, required calibration in order to allow students to more easily use the program. The initial calibration, which can sometimes be difficult and outside the scope of the lesson, was the challenge. The objective was to allow students to bypass the setup and quickly jump into spectroscopy in a colorful and engaging way, while preserving the depth of the task, said Howe.

Spectroscopy is the analysis of the visible spectra emitted by bright stars photographed using a diffusion grating. These spectra provide information about the chemical composition, temperature and classification of stars. Howe explained that, In general, spectroscopy is the analysis of waveform emissions of any object in any wavelength. It happens to be easy and relatively inexpensive to work in the visible spectrum and deal with high-emission objects in that spectrum, like stars.

Stark came into the project with a passion for astrophotography, and she was interested to see if she and Howe could take black and white spectroscopy analysis to a more colorful visual understanding. The presentation involved a paper and poster depicting their discovery, a story line of their process, data they collected and work to be completed in the future.

I am thankful for Dr. Sitar seeing something in me and challenging me to get involved. It is good to have differing opinions and perspectives to work together as a team, and I am positive about the perspective it gives me for my future, Stark said.

Both Howe and Stark will receive an award at the next NCS-AAPT meeting in March. The outstanding undergraduate student award is annually given to recognize broad academic achievement in a rising junior or senior indicated by factors such as: GPA, GPA in physics courses, reference letters, research projects or seminars, a narrative on personal interest in physics and a description of future plans. Our peers were outstanding, so Im very proud that we were chosen for the prize, said Howe.

Stark, who started the project as a communication major, will be changing her major after this project to physics and astronomy. The biggest reason I have not changed yet, was that I wanted to prove to myself that I could do this. I felt challenged beyond my comfort zone, but pushing myself felt good, and this award is definitely a boost in confidence that I am moving in the right direction, she said. Stark said she was very appreciative of the outreach by Sitar to include her on this project, and even though it was difficult, with encouragement and guidance she has grown from this opportunity.

The College of Arts and Sciences is home to 16 academic departments, three stand-alone programs, two centers and one residential college. These units span the humanities, social sciences, and the mathematical and natural sciences. The College of Arts and Sciences aims to develop a distinctive identity built upon our universitys strengths, traditions and unique location. Our values lie not only in service to the university and local community, but through inspiring, training, educating and sustaining the development of our students as global citizens. There are approximately 5,850 student majors in the college. As the college is also largely responsible for implementing Appalachians general education curriculum, it is heavily involved in the education of all students at the university, including those pursuing majors in other colleges.

Appalachian State University, in North Carolinas Blue Ridge Mountains, prepares students to lead purposeful lives as global citizens who understand and engage their responsibilities in creating a sustainable future for all. The transformational Appalachian experience promotes a spirit of inclusion that brings people together in inspiring ways to acquire and create knowledge, to grow holistically, to act with passion and determination, and embrace diversity and difference. As one of 17 campuses in the University of North Carolina system, Appalachian enrolls about 18,000 students, has a low student-to-faculty ratio and offers more than 150 undergraduate and graduate majors.

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Cross-institutional research in physics and astronomy leads to best undergraduate student paper - Appalachian State University