Category Archives: Astronomy

On March 8, 2015, Jupiters moon Europa passed in front of Io, allowing detailed mapping of the bright volcanic crater called Loki Patera (upper left). Credit: Katherine de Kleer

Taking advantage of a rare orbital alignment between two of Jupiters moons, Io and Europa, researchers have obtained an exceptionally detailed map of the largest lava lake on Io, the most volcanically active body in the solar system.

On March 8, 2015, Europa passed in front of Io, gradually blocking out light from the volcanic moon. Because Europas surface is coated in water ice, it reflects very little sunlight at infrared wavelengths, allowing researchers to accurately isolate the heat emanating from volcanoes on Ios surface.

The infrared data showed that the surface temperature of Ios massive molten lake steadily increased from one end to the other, suggesting that the lava had overturned in two waves that each swept from west to east at about a kilometer (3,300 feet) per day.

Overturning lava is a popular explanation for the periodic brightening and dimming of the hot spot, called Loki Patera after the Norse god. (A patera is a bowl-shaped volcanic crater.) The most active volcanic site on Io, which itself is the most volcanically active body in the solar system, Loki Patera is about 200 kilometers (127 miles) across. The hot region of the patera has a surface area of 21,500 square kilometers, larger than Lake Ontario.

Earthbound astronomers first noticed Ios changing brightness in the 1970s, but only when the Voyager 1 and 2 spacecraft flew by in 1979 did it become clear that this was because of volcanic eruptions on the surface. Despite highly detailed images from NASAs Galileo mission in the late 1990s and early 2000s, astronomers continue to debate whether the brightenings at Loki Patera which occur every 400 to 600 days are due to overturning lava in a massive lava lake, or periodic eruptions that spread lava flows over a large area.

If Loki Patera is a sea of lava, it encompasses an area more than a million times that of a typical lava lake on Earth, said Katherine de Kleer, a UC Berkeley graduate student and the studys lead author. In this scenario, portions of cool crust sink, exposing the incandescent magma underneath and causing a brightening in the infrared.

This is the first useful map of the entire patera, said co-author Ashley Davies, of the Jet Propulsion Laboratory in Pasadena, who has studied Ios volcanoes for many years. It shows not one but two resurfacing waves sweeping around the patera. This is much more complex than what was previously thought.

This is a step forward in trying to understand volcanism on Io, which we have been observing for more than 15 years, and in particular the volcanic activity at Loki Patera, said Imke de Pater, a UC Berkeley professor of astronomy.

De Kleer is lead author of a paper reporting the new findings that will be published May 11 in the journal Nature.

Binocular telescope turns two eyes on Io

The images were obtained by the twin 8.4-meter (27.6-foot) mirrors of the Large Binocular Telescope Observatory in the mountains of southeast Arizona, linked together as an interferometer using advanced adaptive optics to remove atmospheric blurring. The facility is operated by an international consortium headquartered at the University of Arizona in Tucson.

Two years earlier, the LBTO had provided the first ground-based images of two separate hot spots within Loki Patera, thanks to the unique resolution offered by the interferometric use of LBT, which is equivalent to what a 23-meter (75-foot) telescope would provide, noted co-author and LBTO director Christian Veillet. This time, however, the exquisite resolution was achieved thanks to the observation of Loki Patera at the time of an occultation by Europa.

Europa took about 10 seconds to completely cover Loki Patera. There was so much infrared light available that we could slice the observations into one-eighth-second intervals during which the edge of Europa advanced only a few kilometers across Ios surface, said co-author Michael Skrutskie, of the University of Virginia, who led the development of the infrared camera used for this study. Loki was covered from one direction but revealed from another, just the arrangement needed to make a real map of the distribution of warm surface within the patera.

These observations gave the astronomers a two-dimensional thermal map of Loki Patera with a resolution better than 10 kilometers (6.25 miles), 10 times better than normally possible with the LBT Interferometer at this wavelength (4.5 microns). The temperature map revealed a smooth temperature variation across the surface of the lake, from about 270 Kelvin at the western end, where the overturning appeared to have started, to 330 Kelvin at the southeastern end, where the overturned lava was freshest and hottest.

Using information on the temperature and cooling rate of magma derived from studies of volcanoes on Earth, de Kleer was able to calculate how recently new magma had been exposed at the surface. The results between 180 and 230 days before the observations at the western end and 75 days before at the eastern agree with earlier data on the speed and timing of the overturn.

Interestingly, the overturning started at different times on two sides of a cool island in the center of the lake that has been there ever since Voyager photographed it in 1979.

The velocity of overturn is also different on the two sides of the island, which may have something to do with the composition of the magma or the amount of dissolved gas in bubbles in the magma, de Kleer said. There must be differences in the magma supply to the two halves of the patera, and whatever is triggering the start of overturn manages to trigger both halves at nearly the same time but not exactly. These results give us a glimpse into the complex plumbing system under Loki Patera.

Lava lakes like Loki Patera overturn because the cooling surface crust slowly thickens until it becomes denser than the underlying magma and sinks, pulling nearby crust with it in a wave that propagates across the surface. According to de Pater, as the crust breaks apart, magma may spurt up as fire fountains, akin to what has been seen in lava lakes on Earth, but on a smaller scale.

De Kleer and de Pater are eager to observe other Io occultations to verify their findings, but theyll have to wait until the next alignment in 2021. For now, de Kleer is happy that the interferometer linking the two telescopes, the adaptive optics on each and the unique occultation came together as planned that night two years ago.

We werent sure that such a complex observation was even going to work, she said, but we were all surprised and pleased that it did.

View post:

[ 10 May 2017 ] Waves of lava seen in Io's largest volcanic crater News - Astronomy Now Online

An artists conception of SIMP J013656.5+093347, or SIMP0136 for short, which the research team determined is a planetary like member of a 200-million-year-old group of stars called Carina-Near. Credit: NASA/JPL, slightly modified by Jonathan Gagn.

Sometimes a brown dwarf is actually a planet or planet-like anyway. A team led by Carnegies Jonathan Gagn, and including researchers from the Institute for Research on Exoplanets (iREx) at Universit de Montral, the American Museum of Natural History, and University of California San Diego, discovered that what astronomers had previously thought was one of the closest brown dwarfs to our own Sun is in fact a planetary mass object.

Their results are published by The Astrophysical Journal Letters.

Smaller than stars, but bigger than giant planets, brown dwarfs are too small to sustain the hydrogen fusion process that fuels stars and allows them to remain hot and bright for a long time. So after formation, brown dwarfs slowly cool down and contract over time. The contraction usually ends after a few hundred million years, although the cooling is continuous.

This means that the temperatures of brown dwarfs can range from as hot as stars to as cool as planets, depending on how old they are, said the AMNHs Jackie Faherty, a co-author on this discovery.

The team determined that a well-studied object known as SIMP J013656.5+093347, or SIMP0136 for short, is a planetary like member of a 200-million-year-old group of stars called Carina-Near.

Groups of similarly aged stars moving together through space are considered prime regions to search for free-floating planetary like objects, because they provide the only means of age-dating these cold and isolated worlds. Knowing the age, as well as the temperature, of a free-floating object like this is necessary to determine its mass.

Gagn and the research team were able to demonstrate that at about 13 times the mass of Jupiter, SIMP0136 is right at the boundary that separates brown dwarf-like properties, primarily the short-lived burning of deuterium in the objects core, from planet-like properties.

Free-floating planetary mass objects are valuable because they are very similar to gas giant exoplanets that orbit around stars, like our own solar systems Jupiter or Saturn, but it is comparatively much easier to study their atmospheres. Observing the atmospheres of exoplanets found within distant star systems is challenging, because dim light emitted by those orbiting exoplanets is overwhelmed by the brightness of their host stars, which blinds the instruments that astronomers use to characterize an exoplanets atmospheres.

The implication that the well-known SIMP0136 is actually more planet-like than we previously thought will help us to better understand the atmospheres of giant planets and how they evolve, Gagn said.

They may be easier to study in great detail, but these free-floating worlds are still extremely hard to discover unless scientists spend a lot of time observing them at the telescope, because they can be located anywhere in the sky and they are very hard to tell apart from brown dwarfs or very small stars. For this reason, researchers have confirmed only a handful of free-floating planetary like objects so far.

tienne Artigau, co-author and leader of the original SIMP0136 discovery, added: This newest addition to the very select club of free-floating planetary like objects is particularly remarkable, because we had already detected fast-evolving weather patterns on the surface of SIMP0136, back when we thought it was a brown dwarf.

In a field where analyzing exoplanet atmospheres is of the utmost interest, having already seen evidence of weather patterns on an easier-to-observe free-floating object that exists away from the brightness of its host star is an exciting realization.

Here is the original post:

[ 9 May 2017 ] Surprise! When a brown dwarf is actually a planetary mass object News - Astronomy Now Online

Galaxy mergers are commonplace throughout the cosmos, building smaller galaxies into larger ones. And when galaxies merge, the supermassive black holes they contain are taken along for the ride. Such large-scale interactions can disrupt material orbiting in the vicinity of the black hole, causing changes in behavior and eventually turning up the accretion rate onto the black hole, creating an active galactic nucleus, or AGN.

Now, a recent study utilizing data from NASAs NuSTAR X-ray telescope has tracked merging galaxies and their black holes to show that during the later stages of this process, the black holes become cocooned in thick swaths of gas and dust, hiding them from the sight even as they gobble material at higher rates.

The study, published in the Monthly Notices of the Royal Astronomical Society, examined 52 supermassive black holes in nearby merging galaxies to determine how galaxies and their black holes grow together, especially during interactions such as mergers. While astronomers know that black holes grow rapidly as gas and dust fall into the singularity, there is still some uncertainty as to how this process is triggered.

Galaxy mergers in particular have often been cited as possible triggering events that could disrupt gas and dust at large distances from the black hole, funneling it into the center of the galaxy where it can lose enough energy to eventually fall into the growing black hole, rather than settle safely into orbit around it.

However, that material can also form a shroud around the black hole, making it more difficult to detect and study. The shroud is so thick that it blocks all but the most energetic light (such as high-energy X-rays) from escaping. Thus, the study was conducted with NuSTAR because of the telescopes sensitivity to high-energy X-rays, whereas other facilities, such as the Chandra X-ray Observatory, the Swift mission, and the X-ray Multi-Mirror Mission (XMM-Newton), are only sensitive to X-rays with lower energies. When high-energy X-rays are detected but low-energy X-rays are missing, astronomers know that the AGN is surrounded by a shell of thick material that isnt letting most of its emission escape.

By comparing the amount of high- and low-energy X-rays observed from their sample of AGN in merging galaxies, the group was able to determine that [t]he further along the merger is, the more enshrouded the AGN will be, explained lead author Claudio Ricci in a press release.

Galaxies that are far along in the merging process are completely covered in a cocoon of gas and dust. In fact, the AGN in the study that resided within galaxies in the later stages of merging (about half the sample) were about 95 percent enshrouded in dust, based on their X-ray emission.

While all active black holes are believed to have some amount of gas and dust in an obscuring torus around them, such a high percentage of obscuration in these particular AGN cant be explained solely by that torus, the authors stated in their study. Instead, it indicates that the galaxy merger has caused large amounts of gas and dust to move into the center of the galaxy, particularly when compared with isolated galaxies that arent undergoing mergers or have just begun to merge.

This study reinforces the idea that AGN tend to do most of their accreting during the later stages of a merger, and are heavily obscured during this time. Said Ricci, The results further our understanding of the mysterious origins of the relationship between a black hole and its host galaxy.

Read more:

Merging galaxies wrap their black holes in dusty shrouds ... - Astronomy Magazine

During its time studying comet 67P/Churyumov-Gerasimenko, the European Space Agency's Rosetta spacecraft revealed that comets are active, dynamic objects with shifting landscapes and complex chemistry. One of Rosettas many discoveries, announced in 2015, was the production of molecular oxygen gas, or O2, on the comet. O2, which is abundant on Earth thanks to biological processes, is otherwise quite rare in the cosmos because it is quickly broken up via chemical processes. While astronomers have had difficulty puzzling out the presence of molecular O2 on 67P, a professor at the California Institute of Technology has found a simple way to explain the comets O2, thanks to his own research in the field of chemical engineering.

Professor Konstantinos P. Giapis and postdoctoral researcher Yunxi Yao have published their results in Nature Communications. In their study, they explain the production of O2 on the comet based on a mechanism seen in their chemical engineering research. In the lab, Giapis and Yao focus on the results of collisions between charged particles, called ions, and the surfaces of semiconducting materials. Their goal is to develop better computer chips with faster response times and increased memory capacity for next-generation electronics. But collisions of this type can also take place on the surface of comets as they near the Sun, providing the source of the O2 measured in comet 67Ps atmosphere as well.

After looking at measurements made on Rosetta's comet, in particular regarding the energies of the water molecules hitting the comet, it all clicked, says Giapis in a press release announcing the study. What I've been studying for years is happening right here on this comet.

How does such a reaction happen? As a comet nears the Sun, its temperature rises as increased radiation strikes the surface. This causes ices on and near the surface to vaporize, throwing off molecules that include water vapor. These molecules encounter ultraviolet radiation from the Sun, which is comprised of highly energetic particles, and lose electrons in the process, becoming charged ions (like those in Giapis lab). These ions are blown back onto the comet by the solar wind, where they encounter materials such as rust, sand, and ice that contain oxygen bound within them. The collision causes the ionized molecules to pick up additional oxygen atoms, resulting in the formation of O2.

Previously, the only explanation for the O2 found in the comets atmosphere was primordial O2 locked away as ices since the formation of the solar system, roughly 4.6 billion years ago. This explanation was problematic, however, as astronomers believed that even as ice, O2 should have reacted with other chemicals over the comets history, rather than remain pristine.

Giapis and Yaos explanation fits much better with the emerging picture Rosetta has painted of comets as dynamic systems. Instead of unlocking primordial O2, reactions between the comet and the increasing sunlight create new O2 in real time. We have shown experimentally that it is possible to form molecular oxygen dynamically on the surface of materials similar to those found on the comet," says Yao.

Because, as Giapis says, [a]ll necessary conditions for such reactions exist on comet 67P, this finding has far-reaching implications for not only our understanding of cometary chemistry in our own solar system, but also the production and presence of O2 on, say, extrasolar planets. If life is not a likely requirement for the presence of O2, it will affect the ways in which astronomers search for potentially habitable or potentially currently inhabited exoplanets in the future.

The study also highlights the benefits of applying science across varying disciplines, showing that mechanisms studied in specialized labs can have amazing applications beyond Earth-based technology.

Here is the original post:

Comet 67P is making its own oxygen gas - Astronomy Magazine

Even Erin Maier is surprised how her academic journey at the University of Iowa has turnedout.

The graduating senior from Hudson, Ohio, enrolled at the UI to study creative writing, then accidentally fell into astronomy, shesays.

Its a good thing she didfor her and for theuniversity.

Hometown: Hudson, Ohio

Area of study: Physics and astronomy

Graduation: May 2017

Activities and honors:

Maier helped design and build sophisticated instruments for UI-commissioned telescopes that are exploring the cosmos and yielding insights into some of the most fundamental questions about theuniverse.

Along the way, she twice won National Science Foundationsponsored internships, is first author on two peer-reviewed papers, and nabbed a coveted Goldwaterscholarship.

Maier will receive aBachelor of Science in physics and astronomy on Saturday, May 13, and is one of more than 4,800 UI students who will graduate during commencement ceremonies at the end of the springsemester.

After commencement, Maier will head to the Graduate Program in Astronomy and Astrophysics at the University of Arizona to pursue a doctorate with a research focus on ground-basedinstrumentation.

Its been a roundabout, strange path, but my experience here has helped me figure out what I want to do with the rest of my life, Maiersays.

Maier had no clue the UI had a physics and astronomy major when she stepped on campus in the fall of 2013. She chose the UI largely based on her high school English teachers recommendation for the universitys strength in creativewriting.

Her academic focus changed in the beginning of her firstyear when she took a General Astronomy class about the solar system taught by Robert Mutel, professor in the UIDepartment of Physics and Astronomy.

I didnt have to take that class, says Maier, adding she had enough advanced placement credits to fulfill that academic requirement. I took it because I wanted to, and Im glad Idid.

Unbeknownst to Maier, Mutel was scouting talent to help with various research projects, a practice he has employed for some time for himself and his colleagues in thedepartment.

Supported by an Iowa Center for Research by Undergraduates fellowship, Maier spent her first summer in Iowa City analyzing radio emissions from the center of the Milky Way with Cornelia Lang, UI associate professor in physics and astronomy. She also helped Mutel install a telescope in the Van Allen Observatory, located on the roof of Van Allen Hall, whichis used for classes and public viewingevents.

Erin and I spent that first summer together working on understanding the complex magnetic properties of the core of our galaxy, Lang says. She is delightful to work with and one of the most passionate and hard-working students Ive gotten to know here at the University ofIowa.

The summer after her sophomore year, Maier ventured to Northern Arizona University and partnered with other undergraduates to study how turbulence in spiral galaxies is associated with star formation. That stint, funded by the NSF Research Experiences for Undergraduates program, led to Maier being chosen as first author on two papers, one of which has been published in The Astronomical Journal. (The other paper also will be published in The Astronomical Journal.)

Though she enjoyed interpreting data gathered by the telescopes, Maier began leaning toward a focus ininstrumentation.

I just started thinking, What if I was building those instruments? That would be so cool, shesays.

Fortunately, Mutel had some ideas. In the spring of 2015, he invited six undergraduates, including Maier, to take a semester-long research class in which they prepared to install a new, $125,000 telescope funded by the Roy J. Carver Charitable Trust. The students divided into teams to learn the ins and outs of telescope operation, instrumentation, andassembly.

That May, Mutel and the students traveled to Arizona. The telescope, called the Iowa Robotic Observatory, arrived in a box the size of a car, Mutel recalls, like some massive Lego set that needed to be built fromscratch.

They tested the instrument; they assembled the main telescope and the mount; they tested its capabilities; and they put on the instruments, the spectrometer, the camera, the main wheel, et cetera, Mutel says. They basically made it an operating telescope in a few days. It was very impressive,actually.

It came with some tense moments, though. For three days, Maier and her fellow students were unable to test the telescope, deterred by cloudy nights. On the last night, Maier and two others didnt sleep, instead capturing as many clear-sky viewings aspossible.

We came out of observing at five in the morning, and we were like, Yeah, we did this! shesays.

They were very dedicated, I can tell you, Muteladds.

The first images gathered by the Iowa Robotic Observatory havedrawn more than 461,000 views on the image-sharing platformImgur.

They were beautiful, gorgeous images that with the previous telescope would have taken much longer, with a fraction of the quality, Maiersays.

Maier was awarded a second NSF REU scholarship to help build a camera that would allow astronomers to make observations of star clusters in two optical wavelengths simultaneously, which cuts the background clutter in the images that are being observed. The instrument was successfully tested at the McDonald Observatory in westTexas.

At the end of this, any doubts I had with my interest in instrumentation had vanished, Maiersays.

Maier volunteered at the Van Allen Observatory and otherwise availed herself of any opportunity she could find to learn more and beinvolved.

I would say shes what you might call a good citizen, Mutel says. Shes been involved in the Society of Physics students (a student leadership program). She goes to seminars in the department. In that sense, shes much more like faculty and graduate students, who are invested in the life of thedepartment.

See more here:

Graduating UI senior takes 'roundabout' journey to astronomy - Iowa Now

A University of Wyoming professor and the endowed chair of physics will bring his experience with solar eclipses to Gillette on May 16 to prepare local residents for the Great North American Solar Eclipse in August.

Gillette and much of Wyoming is in the path of the total solar eclipse Aug. 21 that will be the first to hit the contiguous United States in 38 years, and the first one to cover so much of the U.S. since 1918.

As a result, many people from across the world are traveling to the state where the view will range from 97 percent total in Gillette to 99 percent in Casper.

Tim Slater will bring an interactive presentation to Gillette on how to safely watch a solar eclipse and use computer simulations to explain why scientists from all over the world are coming to Wyoming to observe the once-in-a-lifetime event. Hell speak about the nature of eclipses and also hand out free eclipse-viewing glasses.

Of his six presentations planned in Gillette, four are open to the public free of charge.

Hell present his 30-minute lecture to astronomy classes at Campbell County High School at 8 a.m. and 9:30 a.m. May 16 at the North Campus.

Then hell give two more programs, open to the public, at the Campbell County Public Library at 4 p.m. and 4:45 p.m.

That will be followed by two programs, also open to the public, at 7 and 7:45 p.m. in the planetarium at Sage Valley Junior High. Those interested in attending the planetarium classes still have to reserve a seat online, but the program is free. Visit supersaas.com/schedule/CCSD/Planetarium to reserve a seat, email planet@ccsd.k12.wy.us or call 307-682-4307 to leave a message.

Paul Zeleski, director of the planetarium, said Slater contacted him about offering programs in Gillette because Slater is also one of his science instructors. Slater has offered the same program in other areas of the state, including Lander and Star Valley.

Hes a smart guy, Zeleski said. Hes energetic and extremely knowledgeable.

Slater joined the UW College of Education faculty in 2008-09 as the first recipient of the Wyoming Excellence in Higher Education Endowed Chair in Science Education. He was an associate professor of astronomy at the University of Arizona at the time, where he founded the internationally recognized Conceptual Astronomy and Physics Education Research Team.

Throughout May, hes traveling across Wyoming to visit schools, public libraries and community centers to build awareness, generate excitement and help children, parents, teachers and community leaders prepare for the total eclipse of the sun.

The rest is here:

UW astronomy expert brings eclipse lessons - Gillette News Record

A South Derbyshire observatory is bidding to bag a massive cash boost from the Tesco Bags of Help initiative to help build an observatory which has been years in the planning. Rosliston Astronomy Group has secured most of the funding for the new facility, but also hopes to build a ramp which will enable people with disabilities to use the space-gazing building.

Now, organisers are urging people to vote for the project in Tesco and if their project wins the overall vote, they could be presented with 4,000 all raised from the 5p plastic bag levy.

The group's overall project is called "Outreach to the Stars", which aims to develop its work with a number of community groups around Burton and South Derbyshire.

With the observatory set to be completed in July 2017, they are hoping to raise the funds to provide an access pathway to the observatory, suitable for everyone, including those with disabilities.

Heather Lomas, treasurer for the group said: "A pathway is crucial to the success of our overall project - and will benefit a much larger group of people, young and old, interested in the sun and the stars."

"Rosliston Astronomy Group has been carrying out a range of community "outreach" activities for 17 years.We believe in encouraging lifelong learning and raising aspirations for all community groups not just our members.

"We voluntarily support Rosliston Forestry Centre, providing the astronomy aspect, at their events for the general public such as weekend science days, "Bat, Moth and Astronomy" evenings, and we hold our own events such as the solar eclipse - when more than 200 people attended.

"We work regularly with primary and secondary school class groups, with scouts, guides, and give practically-based talks to various adult groups.

"Over time at Rosliston we have noted that a number of people in the general public and community groups have found outdoor 'observing' very challenging, both during the day and even more so during the evening - using an unfamiliar object like an eyepiece, having to balance on uneven ground, in often cold temperatures, frequently in the dark - especially children, the elderly, infirm, and those with disabilities, including wheelchair users.

"To resolve these problems we have for the last two years been raising funds to build an observatory.

"Burton Mail readers have helped with this. We are grateful to South Derbyshire District Council for leasing us the land, and to the Forestry Commission for supporting us.

"The observatory will give us a safe, indoor environment with all its health and safety, enabling us to engage with an even-wider community, such as parent and child 'shared' learning, and disability groups, in addition to all the other groups - both for solar and night sky observing.

"We will be able to deliver 'practically based' learning and experiences to a much wider audience, including those who would never be able to access or afford such equipment themselves.

"However, none of this can happen unless we have a suitable access pathway, and this is why we are asking the people using Tesco Stores in and around Burton, Swadlincote, Woodville and Measham, and anyone else who are able to do so, to please help us by choosing our project ' Outreach to the Stars' for your tokens - please ask for one."

Voting is open in stores throughout May and June. Customers will cast their vote using a token given to them at the check-out in store each time they shop.

Tesco's Bags of Help project has already delivered over 28.5 million to more than 4,000 projects up and down the UK.

Every other month, when votes are collected, three groups in each of Tesco's regions will be awarded funding.

Lindsey Crompton, head of community at Tesco, said: "We are absolutely delighted to open the voting for May and June. There are some fantastic projects on the shortlists and we can't wait to see them come to life in hundreds of communities."

The new community-use observatory will be built this summer after the South Derbyshire astronomy group hit their fund-raising target of 20,000. It is hoped it will allow people young and old to discover the wonders of the universe.

They were boosted by a 10,000 grant from the South Derbyshire Community Partnership Fund.

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

Mrs Lomas said: "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."

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

*Read more of today's top news stories here.

Follow the Burton Mail on Facebook and Twitter

See the original post:

Rosliston Astronomy Group is asking shoppers to vote for them to win Tesco Bags of Help cash - Burton Mail

Astronomy (from Greek: ) is a natural science that studies celestial objects and phenomena. It applies mathematics, physics, and chemistry, in an effort to explain the origin of those objects and phenomena and their evolution. Objects of interest include planets, moons, stars, galaxies, and comets; while the phenomena include supernovae explosions, gamma ray bursts, and cosmic microwave background radiation. More generally, all astronomical phenomena that originate outside Earth's atmosphere are within the purview of astronomy. A related but distinct subject, physical cosmology, is concerned with the study of the Universe as a whole.[1]

Astronomy is the oldest of the natural sciences. The early civilizations in recorded history, such as the Babylonians, Greeks, Indians, Egyptians, Nubians, Iranians, Chinese, and Maya performed methodical observations of the night sky. Historically, astronomy has included disciplines as diverse as astrometry, celestial navigation, observational astronomy and the making of calendars, but professional astronomy is now often considered to be synonymous with astrophysics.[2]

During the 20th century, the field of professional astronomy split into observational and theoretical branches. Observational astronomy is focused on acquiring data from observations of astronomical objects, which is then analyzed using basic principles of physics. Theoretical astronomy is oriented toward the development of computer or analytical models to describe astronomical objects and phenomena. The two fields complement each other, with theoretical astronomy seeking to explain the observational results and observations being used to confirm theoretical results.

Astronomy is one of the few sciences where amateurs can still play an active role, especially in the discovery and observation of transient phenomena. Amateur astronomers have made and contributed to many important astronomical discoveries, such as finding new comets.

Astronomy (from the Greek from astron, "star" and - -nomia from nomos, "law" or "culture") means "law of the stars" (or "culture of the stars" depending on the translation). Astronomy should not be confused with astrology, the belief system which claims that human affairs are correlated with the positions of celestial objects.[5] Although the two fields share a common origin, they are now entirely distinct.[6]

Generally, either the term "astronomy" or "astrophysics" may be used to refer to this subject.[7][8][9] Based on strict dictionary definitions, "astronomy" refers to "the study of objects and matter outside the Earth's atmosphere and of their physical and chemical properties"[10] and "astrophysics" refers to the branch of astronomy dealing with "the behavior, physical properties, and dynamic processes of celestial objects and phenomena".[11] In some cases, as in the introduction of the introductory textbook The Physical Universe by Frank Shu, "astronomy" may be used to describe the qualitative study of the subject, whereas "astrophysics" is used to describe the physics-oriented version of the subject.[12] However, since most modern astronomical research deals with subjects related to physics, modern astronomy could actually be called astrophysics.[7] Few fields, such as astrometry, are purely astronomy rather than also astrophysics. Various departments in which scientists carry out research on this subject may use "astronomy" and "astrophysics," partly depending on whether the department is historically affiliated with a physics department,[8] and many professional astronomers have physics rather than astronomy degrees.[9] Some titles of the leading scientific journals in this field includeThe Astronomical Journal, The Astrophysical Journal and Astronomy and Astrophysics.

In early times, astronomy only comprised the observation and predictions of the motions of objects visible to the naked eye. In some locations, early cultures assembled massive artifacts that possibly had some astronomical purpose. In addition to their ceremonial uses, these observatories could be employed to determine the seasons, an important factor in knowing when to plant crops, as well as in understanding the length of the year.[13]

Before tools such as the telescope were invented, early study of the stars was conducted using the naked eye. As civilizations developed, most notably in Mesopotamia, Greece, Persia, India, China, Egypt, and Central America, astronomical observatories were assembled, and ideas on the nature of the Universe began to be explored. Most of early astronomy actually consisted of mapping the positions of the stars and planets, a science now referred to as astrometry. From these observations, early ideas about the motions of the planets were formed, and the nature of the Sun, Moon and the Earth in the Universe were explored philosophically. The Earth was believed to be the center of the Universe with the Sun, the Moon and the stars rotating around it. This is known as the geocentric model of the Universe, or the Ptolemaic system, named after Ptolemy.[14]

A particularly important early development was the beginning of mathematical and scientific astronomy, which began among the Babylonians, who laid the foundations for the later astronomical traditions that developed in many other civilizations.[15] The Babylonians discovered that lunar eclipses recurred in a repeating cycle known as a saros.[16]

Following the Babylonians, significant advances in astronomy were made in ancient Greece and the Hellenistic world. Greek astronomy is characterized from the start by seeking a rational, physical explanation for celestial phenomena.[17] In the 3rd century BC, Aristarchus of Samos estimated the size and distance of the Moon and Sun, and was the first to propose a heliocentric model of the solar system.[18] In the 2nd century BC, Hipparchus discovered precession, calculated the size and distance of the Moon and invented the earliest known astronomical devices such as the astrolabe.[19] Hipparchus also created a comprehensive catalog of 1020 stars, and most of the constellations of the northern hemisphere derive from Greek astronomy.[20] The Antikythera mechanism (c. 15080 BC) was an early analog computer designed to calculate the location of the Sun, Moon, and planets for a given date. Technological artifacts of similar complexity did not reappear until the 14th century, when mechanical astronomical clocks appeared in Europe.[21]

During the Middle Ages, astronomy was mostly stagnant in medieval Europe, at least until the 13th century. However, astronomy flourished in the Islamic world and other parts of the world. This led to the emergence of the first astronomical observatories in the Muslim world by the early 9th century.[22][23][24] In 964, the Andromeda Galaxy, the largest galaxy in the Local Group, was discovered by the Persian astronomer Azophi and first described in his Book of Fixed Stars.[25] The SN 1006 supernova, the brightest apparent magnitude stellar event in recorded history, was observed by the Egyptian Arabic astronomer Ali ibn Ridwan and the Chinese astronomers in 1006. Some of the prominent Islamic (mostly Persian and Arab) astronomers who made significant contributions to the science include Al-Battani, Thebit, Azophi, Albumasar, Biruni, Arzachel, Al-Birjandi, and the astronomers of the Maragheh and Samarkand observatories. Astronomers during that time introduced many Arabic names now used for individual stars.[26][27] It is also believed that the ruins at Great Zimbabwe and Timbuktu[28] may have housed an astronomical observatory.[29] Europeans had previously believed that there had been no astronomical observation in pre-colonial Middle Ages sub-Saharan Africa but modern discoveries show otherwise.[30][31][32][33]

The Roman Catholic Church gave more financial and social support to the study of astronomy for over six centuries, from the recovery of ancient learning during the late Middle Ages into the Enlightenment, than any other, and, probably, all other, institutions. Among the Church's motives was finding the date for Easter.[34]

During the Renaissance, Nicolaus Copernicus proposed a heliocentric model of the solar system. His work was defended, expanded upon, and corrected by Galileo Galilei and Johannes Kepler. Galileo used telescopes to enhance his observations.[35]

Kepler was the first to devise a system that described correctly the details of the motion of the planets with the Sun at the center. However, Kepler did not succeed in formulating a theory behind the laws he wrote down.[36] It was left to Newton's invention of celestial dynamics and his law of gravitation to finally explain the motions of the planets. Newton also developed the reflecting telescope.[35]

The English astronomer John Flamsteed catalogued over 3000 stars.[37] Further discoveries paralleled the improvements in the size and quality of the telescope. More extensive star catalogues were produced by Lacaille. The astronomer William Herschel made a detailed catalog of nebulosity and clusters, and in 1781 discovered the planet Uranus, the first new planet found.[38] The distance to a star was first announced in 1838 when the parallax of 61 Cygni was measured by Friedrich Bessel.[39]

During the 1819th centuries, the study of the three body problem by Euler, Clairaut, and D'Alembert led to more accurate predictions about the motions of the Moon and planets. This work was further refined by Lagrange and Laplace, allowing the masses of the planets and moons to be estimated from their perturbations.[40]

Significant advances in astronomy came about with the introduction of new technology, including the spectroscope and photography. Fraunhofer discovered about 600 bands in the spectrum of the Sun in 181415, which, in 1859, Kirchhoff ascribed to the presence of different elements. Stars were proven to be similar to the Earth's own Sun, but with a wide range of temperatures, masses, and sizes.[26]

The existence of the Earth's galaxy, the Milky Way, as a separate group of stars, was only proved in the 20th century, along with the existence of "external" galaxies. The observed recession of those galaxies led to the discovery of the expansion of the Universe.[41] Theoretical astronomy led to speculations on the existence of objects such as black holes and neutron stars, which have been used to explain such observed phenomena as quasars, pulsars, blazars, and radio galaxies. Physical cosmology made huge advances during the 20th century, with the model of the Big Bang, which is heavily supported by evidence provided by cosmic microwave background radiation, Hubble's law, and the cosmological abundances of elements. Space telescopes have enabled measurements in parts of the electromagnetic spectrum normally blocked or blurred by the atmosphere. In February 2016, it was revealed that the LIGO project had detected evidence of gravitational waves in the previous September.

Our main source of information about celestial bodies and other objects is visible light more generally electromagnetic radiation.[42] Observational astronomy may be divided according to the observed region of the electromagnetic spectrum. Some parts of the spectrum can be observed from the Earth's surface, while other parts are only observable from either high altitudes or outside the Earth's atmosphere. Specific information on these subfields is given below.

Radio astronomy uses radiation outside the visible range with wavelengths greater than approximately one millimeter.[43] Radio astronomy is different from most other forms of observational astronomy in that the observed radio waves can be treated as waves rather than as discrete photons. Hence, it is relatively easier to measure both the amplitude and phase of radio waves, whereas this is not as easily done at shorter wavelengths.[43]

Although some radio waves are emitted directly by astronomical objects, a product of thermal emission, most of the radio emission that is observed is the result of synchrotron radiation, which is produced when electrons orbit magnetic fields.[43] Additionally, a number of spectral lines produced by interstellar gas, notably the hydrogen spectral line at 21cm, are observable at radio wavelengths.[12][43]

A wide variety of objects are observable at radio wavelengths, including supernovae, interstellar gas, pulsars, and active galactic nuclei.[12][43]

Infrared astronomy is founded on the detection and analysis of infrared radiation, wavelengths longer than red light and outside the range of our vision. The infrared spectrum is useful for studying objects that are too cold to radiate visible light, such as planets, circumstellar disks or nebulae whose light is blocked by dust. The longer wavelengths of infrared can penetrate clouds of dust that block visible light, allowing the observation of young stars embedded in molecular clouds and the cores of galaxies. Observations from the Wide-field Infrared Survey Explorer (WISE) have been particularly effective at unveiling numerous Galactic protostars and their host star clusters.[45][46] With the exception of infrared wavelengths close to visible light, such radiation is heavily absorbed by the atmosphere, or masked, as the atmosphere itself produces significant infrared emission. Consequently, infrared observatories have to be located in high, dry places on Earth or in space.[47] Some molecules radiate strongly in the infrared. This allows the study of the chemistry of space; more specifically it can detect water in comets.[48]

Historically, optical astronomy, also called visible light astronomy, is the oldest form of astronomy.[49] Images of observations were originally drawn by hand. In the late 19th century and most of the 20th century, images were made using photographic equipment. Modern images are made using digital detectors, particularly using charge-coupled devices (CCDs) and recorded on modern medium. Although visible light itself extends from approximately 4000 to 7000 (400 nm to 700nm),[49] that same equipment can be used to observe some near-ultraviolet and near-infrared radiation.

Ultraviolet astronomy employs ultraviolet wavelengths between approximately 100 and 3200 (10 to 320nm).[43] Light at those wavelengths are absorbed by the Earth's atmosphere, requiring observations at these wavelengths to be performed from the upper atmosphere or from space. Ultraviolet astronomy is best suited to the study of thermal radiation and spectral emission lines from hot blue stars (OB stars) that are very bright in this wave band. This includes the blue stars in other galaxies, which have been the targets of several ultraviolet surveys. Other objects commonly observed in ultraviolet light include planetary nebulae, supernova remnants, and active galactic nuclei.[43] However, as ultraviolet light is easily absorbed by interstellar dust, an adjustment of ultraviolet measurements is necessary.[43]

X-ray astronomy uses X-ray wavelengths. Typically, X-ray radiation is produced by synchrotron emission (the result of electrons orbiting magnetic field lines), thermal emission from thin gases above 107 (10million) kelvins, and thermal emission from thick gases above 107 Kelvin.[43] Since X-rays are absorbed by the Earth's atmosphere, all X-ray observations must be performed from high-altitude balloons, rockets, or X-ray astronomy satellites. Notable X-ray sources include X-ray binaries, pulsars, supernova remnants, elliptical galaxies, clusters of galaxies, and active galactic nuclei.[43]

Gamma ray astronomy observes astronomical objects at the shortest wavelengths of the electromagnetic spectrum. Gamma rays may be observed directly by satellites such as the Compton Gamma Ray Observatory or by specialized telescopes called atmospheric Cherenkov telescopes.[43] The Cherenkov telescopes do not detect the gamma rays directly but instead detect the flashes of visible light produced when gamma rays are absorbed by the Earth's atmosphere.[50]

Most gamma-ray emitting sources are actually gamma-ray bursts, objects which only produce gamma radiation for a few milliseconds to thousands of seconds before fading away. Only 10% of gamma-ray sources are non-transient sources. These steady gamma-ray emitters include pulsars, neutron stars, and black hole candidates such as active galactic nuclei.[43]

In addition to electromagnetic radiation, a few other events originating from great distances may be observed from the Earth.

In neutrino astronomy, astronomers use heavily shielded underground facilities such as SAGE, GALLEX, and Kamioka II/III for the detection of neutrinos. The vast majority of the neutrinos streaming through the Earth originate from the Sun, but 24 neutrinos were also detected from supernova 1987A.[43]Cosmic rays, which consist of very high energy particles (atomic nuclei) that can decay or be absorbed when they enter the Earth's atmosphere, result in a cascade of secondary particles which can be detected by current observatories.[51] Some future neutrino detectors may also be sensitive to the particles produced when cosmic rays hit the Earth's atmosphere.[43]

Gravitational-wave astronomy is an emerging field of astronomy that employs gravitational-wave detectors to collect observational data about distant massive objects. A few observatories have been constructed, such as the Laser Interferometer Gravitational Observatory LIGO. LIGO made its first detection on 14 September 2015, observing gravitational waves from a binary black hole.[52] A second gravitational wave was detected on 26 December 2015 and additional observations should continue but gravitational waves require extremely sensitive instruments.[53][54]

The combination of observations made using electromagnetic radiation, neutrinos or gravitational waves and other complementary information, is known as multi-messenger astronomy.[55][56]

One of the oldest fields in astronomy, and in all of science, is the measurement of the positions of celestial objects. Historically, accurate knowledge of the positions of the Sun, Moon, planets and stars has been essential in celestial navigation (the use of celestial objects to guide navigation) and in the making of calendars.

Careful measurement of the positions of the planets has led to a solid understanding of gravitational perturbations, and an ability to determine past and future positions of the planets with great accuracy, a field known as celestial mechanics. More recently the tracking of near-Earth objects will allow for predictions of close encounters or potential collisions of the Earth with those objects.[57]

The measurement of stellar parallax of nearby stars provides a fundamental baseline in the cosmic distance ladder that is used to measure the scale of the Universe. Parallax measurements of nearby stars provide an absolute baseline for the properties of more distant stars, as their properties can be compared. Measurements of the radial velocity and proper motion motion of stars allows astronomers to plot the movement of these systems through the Milky Way galaxy. Astrometric results are the basis used to calculate the distribution of speculated dark matter in the galaxy.[58]

During the 1990s, the measurement of the stellar wobble of nearby stars was used to detect large extrasolar planets orbiting those stars.[59]

Theoretical astronomers use several tools including analytical models and computational numerical simulations; each has its particular advantages. Analytical models of a process are generally better for giving broader insight into the heart of what is going on. Numerical models reveal the existence of phenomena and effects otherwise unobserved.[60][61]

Theorists in astronomy endeavor to create theoretical models and from the results predict observational consequences of those models. The observation of a phenomenon predicted by a model allows astronomers to select between several alternate or conflicting models as the one best able to describe the phenomena.

Theorists also try to generate or modify models to take into account new data. In the case of an inconsistency between the data and model's results, the general tendency is to try to make minimal modifications to the model so that it produces results that fit the data. In some cases, a large amount of inconsistent data over time may lead to total abandonment of a model.

Phenomena modeled by theoretical astronomers include: stellar dynamics and evolution; galaxy formation; large-scale distribution of matter in the Universe; origin of cosmic rays; general relativity and physical cosmology, including string cosmology and astroparticle physics. Astrophysical relativity serves as a tool to gauge the properties of large scale structures for which gravitation plays a significant role in physical phenomena investigated and as the basis for black hole (astro)physics and the study of gravitational waves.

Some widely accepted and studied theories and models in astronomy, now included in the Lambda-CDM model are the Big Bang, Cosmic inflation, dark matter, and fundamental theories of physics.

A few examples of this process:

Dark matter and dark energy are the current leading topics in astronomy,[62] as their discovery and controversy originated during the study of the galaxies.

At a distance of about eight light-minutes, the most frequently studied star is the Sun, a typical main-sequence dwarf star of stellar class G2 V, and about 4.6 billion years (Gyr) old. The Sun is not considered a variable star, but it does undergo periodic changes in activity known as the sunspot cycle. This is an 11-year oscillation in sunspot number. Sunspots are regions of lower-than- average temperatures that are associated with intense magnetic activity.[63]

The Sun has steadily increased in luminosity by 40% since it first became a main-sequence star. The Sun has also undergone periodic changes in luminosity that can have a significant impact on the Earth.[64] The Maunder minimum, for example, is believed to have caused the Little Ice Age phenomenon during the Middle Ages.[65]

The visible outer surface of the Sun is called the photosphere. Above this layer is a thin region known as the chromosphere. This is surrounded by a transition region of rapidly increasing temperatures, and finally by the super-heated corona.

At the center of the Sun is the core region, a volume of sufficient temperature and pressure for nuclear fusion to occur. Above the core is the radiation zone, where the plasma conveys the energy flux by means of radiation. Above that is the convection zone where the gas material transports energy primarily through physical displacement of the gas known as convection. It is believed that the movement of mass within the convection zone creates the magnetic activity that generates sunspots.[63]

A solar wind of plasma particles constantly streams outward from the Sun until, at the outermost limit of the Solar System, it reaches the heliopause. As the solar wind passes the Earth, it interacts with the Earth's magnetic field (magnetosphere) and deflects the solar wind, but traps some creating the Van Allen radiation belts that envelop the Earth . The aurora are created when solar wind particles are guided by the magnetic flux lines into the Earth's polar regions where the lines the descend into the atmosphere.[66]

Planetary science is the study of the assemblage of planets, moons, dwarf planets, comets, asteroids, and other bodies orbiting the Sun, as well as extrasolar planets. The Solar System has been relatively well-studied, initially through telescopes and then later by spacecraft. This has provided a good overall understanding of the formation and evolution of this planetary system, although many new discoveries are still being made.[67]

The Solar System is subdivided into the inner planets, the asteroid belt, and the outer planets. The inner terrestrial planets consist of Mercury, Venus, Earth, and Mars. The outer gas giant planets are Jupiter, Saturn, Uranus, and Neptune.[68] Beyond Neptune lies the Kuiper Belt, and finally the Oort Cloud, which may extend as far as a light-year.

The planets were formed 4.6 billion years ago in the protoplanetary disk that surrounded the early Sun. Through a process that included gravitational attraction, collision, and accretion, the disk formed clumps of matter that, with time, became protoplanets. The radiation pressure of the solar wind then expelled most of the unaccreted matter, and only those planets with sufficient mass retained their gaseous atmosphere. The planets continued to sweep up, or eject, the remaining matter during a period of intense bombardment, evidenced by the many impact craters on the Moon. During this period, some of the protoplanets may have collided and one such collision may have formed the Moon.[69]

Once a planet reaches sufficient mass, the materials of different densities segregate within, during planetary differentiation. This process can form a stony or metallic core, surrounded by a mantle and an outer crust. The core may include solid and liquid regions, and some planetary cores generate their own magnetic field, which can protect their atmospheres from solar wind stripping.[70]

A planet or moon's interior heat is produced from the collisions that created the body, by the decay of radioactive materials (e.g. uranium, thorium, and 26Al), or tidal heating caused by interactions with other bodies. Some planets and moons accumulate enough heat to drive geologic processes such as volcanism and tectonics. Those that accumulate or retain an atmosphere can also undergo surface erosion from wind or water. Smaller bodies, without tidal heating, cool more quickly; and their geological activity ceases with the exception of impact cratering.[71]

The study of stars and stellar evolution is fundamental to our understanding of the Universe. The astrophysics of stars has been determined through observation and theoretical understanding; and from computer simulations of the interior.[72]Star formation occurs in dense regions of dust and gas, known as giant molecular clouds. When destabilized, cloud fragments can collapse under the influence of gravity, to form a protostar. A sufficiently dense, and hot, core region will trigger nuclear fusion, thus creating a main-sequence star.[73]

Almost all elements heavier than hydrogen and helium were created inside the cores of stars.[72]

The characteristics of the resulting star depend primarily upon its starting mass. The more massive the star, the greater its luminosity, and the more rapidly it fuses its hydrogen fuel into helium in its core. Over time, this hydrogen fuel is completely converted into helium, and the star begins to evolve. The fusion of helium requires a higher core temperature. A star with a high enough core temperature will push its outer layers outward while increasing its core density. The resulting red giant formed by the expanding outer layers enjoys a brief life span, before the helium fuel in the core is in turn consumed. Very massive stars can also undergo a series of evolutionary phases, as they fuse increasingly heavier elements.[74]

The final fate of the star depends on its mass, with stars of mass greater than about eight times the Sun becoming core collapse supernovae;[75] while smaller stars blow off their outer layers and leave behind the inert core in the form of a white dwarf. The ejection of the outer layers forms a planetary nebulae.[76] The remnant of a supernova is a dense neutron star, or, if the stellar mass was at least three times that of the Sun, a black hole.[77] Closely orbiting binary stars can follow more complex evolutionary paths, such as mass transfer onto a white dwarf companion that can potentially cause a supernova.[78] Planetary nebulae and supernovae distribute the "metals" produced in the star by fusion to the interstellar medium; without them, all new stars (and their planetary systems) would be formed from hydrogen and helium alone.[79]

Our solar system orbits within the Milky Way, a barred spiral galaxy that is a prominent member of the Local Group of galaxies. It is a rotating mass of gas, dust, stars and other objects, held together by mutual gravitational attraction. As the Earth is located within the dusty outer arms, there are large portions of the Milky Way that are obscured from view.

In the center of the Milky Way is the core, a bar-shaped bulge with what is believed to be a supermassive black hole at its center. This is surrounded by four primary arms that spiral from the core. This is a region of active star formation that contains many younger, population I stars. The disk is surrounded by a spheroid halo of older, population II stars, as well as relatively dense concentrations of stars known as globular clusters.[80]

Between the stars lies the interstellar medium, a region of sparse matter. In the densest regions, molecular clouds of molecular hydrogen and other elements create star-forming regions. These begin as a compact pre-stellar core or dark nebulae, which concentrate and collapse (in volumes determined by the Jeans length) to form compact protostars.[73]

As the more massive stars appear, they transform the cloud into an H II region (ionized atomic hydrogen) of glowing gas and plasma. The stellar wind and supernova explosions from these stars eventually cause the cloud to disperse, often leaving behind one or more young open clusters of stars. These clusters gradually disperse, and the stars join the population of the Milky Way.[81]

Kinematic studies of matter in the Milky Way and other galaxies have demonstrated that there is more mass than can be accounted for by visible matter. A dark matter halo appears to dominate the mass, although the nature of this dark matter remains undetermined.[82]

The study of objects outside our galaxy is a branch of astronomy concerned with the formation and evolution of Galaxies, their morphology (description) and classification, the observation of active galaxies, and at a larger scale, the groups and clusters of galaxies. Finally, the latter is important for the understanding of the large-scale structure of the cosmos.

Most galaxies are organized into distinct shapes that allow for classification schemes. They are commonly divided into spiral, elliptical and Irregular galaxies.[83]

As the name suggests, an elliptical galaxy has the cross-sectional shape of an ellipse. The stars move along random orbits with no preferred direction. These galaxies contain little or no interstellar dust, few star-forming regions, and generally older stars. Elliptical galaxies are more commonly found at the core of galactic clusters, and may have been formed through mergers of large galaxies.

A spiral galaxy is organized into a flat, rotating disk, usually with a prominent bulge or bar at the center, and trailing bright arms that spiral outward. The arms are dusty regions of star formation within which massive young stars produce a blue tint. Spiral galaxies are typically surrounded by a halo of older stars. Both the Milky Way and one of our nearest galaxy neighbors, the Andromeda Galaxy, are spiral galaxies.

Irregular galaxies are chaotic in appearance, and are neither spiral nor elliptical. About a quarter of all galaxies are irregular, and the peculiar shapes of such galaxies may be the result of gravitational interaction.

An active galaxy is a formation that emits a significant amount of its energy from a source other than its stars, dust and gas. It is powered by a compact region at the core, thought to be a super-massive black hole that is emitting radiation from in-falling material.

A radio galaxy is an active galaxy that is very luminous in the radio portion of the spectrum, and is emitting immense plumes or lobes of gas. Active galaxies that emit shorter frequency, high-energy radiation include Seyfert galaxies, Quasars, and Blazars. Quasars are believed to be the most consistently luminous objects in the known universe.[84]

The large-scale structure of the cosmos is represented by groups and clusters of galaxies. This structure is organized into a hierarchy of groupings, with the largest being the superclusters. The collective matter is formed into filaments and walls, leaving large voids between.[85]

-13

-12

-11

-10

-9

-8

-7

-6

-5

-4

-3

-2

-1

0

Cosmology (from the Greek (kosmos) "world, universe" and (logos) "word, study" or literally "logic") could be considered the study of the Universe as a whole.

Observations of the large-scale structure of the Universe, a branch known as physical cosmology, have provided a deep understanding of the formation and evolution of the cosmos. Fundamental to modern cosmology is the well-accepted theory of the big bang, wherein our Universe began at a single point in time, and thereafter expanded over the course of 13.8 billion years[86] to its present condition.[87] The concept of the big bang can be traced back to the discovery of the microwave background radiation in 1965.[87]

In the course of this expansion, the Universe underwent several evolutionary stages. In the very early moments, it is theorized that the Universe experienced a very rapid cosmic inflation, which homogenized the starting conditions. Thereafter, nucleosynthesis produced the elemental abundance of the early Universe.[87] (See also nucleocosmochronology.)

Read the original post:

Astronomy - Wikipedia

Photo by Eric Goodwin / Assistant News Editor

Astronomy and Physics Professor Eric Klumpe provided a lecture on eclipses Friday night in the Wiser-Patten Science Hall as a part of MTSUs First Friday Star Party series.

The lecture, titled Funky Fiziks in Film, addressedmovies involving eclipses and the upcoming solar eclipse that will occur on Aug. 21.

Klumpe explained how a solar eclipse occurs when the Earths moon passes in between the Earth and the Sun, casting a shadow across the face of the Earth. While these eclipses take place about twice a year, this one is special.

The place where (the moons shadow) touches the Earth is the continental United States. And the path, which is very narrow, includes Tennessee, he said.

Murfreesboro lies along the path of totality, meaning the sun will be obscured almost completely in Murfreesboro for a few moments.

Klumpe said the moons shadow is just a little pinpoint of darkness, and we happen to be on that path.

The eclipse, whose path of totality hasnt crossedthe Middle Tennessee regionsince 1478, will occur at roughly noon. The moon will block part of the sun for about three hours, culminating in totality for about one and a half minutes at around 1:30 p.m.

The next eclipse like this wont occur until the year 2566.

Klumpe also talked about movies in pop culture that feature solar eclipses and their hard-to-catch inaccuracies.

For example, in the 1985 film, Ladyhawke, the solar eclipse moves from left to right across the sun. Klumpe explained how the movies setting in the Northern Hemisphere means the moon should pass from the right side of the sun to the left when observed from the Earth.

Klumpe also talked about the eclipse scenes in the 1949 movie, A Connecticut Yankee in King Arthurs Court, and the 2002 movie, The Wild Thornberrys Movie.

Monty Hershberger, 43, came to the star party for the first time on Friday.

It was all very enjoyable, Hershberger said. I enjoyed (Klumpes) humor and the clips that he used to talk about it. So, it was fun.

Hershberger said he and his family will prepare for the August eclipse by hanging outside and enjoying a picnic.

Klumpe, who used to host all of the star parties when the series began, recommended attendees to take an astronomy course at MTSU regardless of their major.

Youre going to learn a lot of things youve never thought about before, he said.

To contact News Editor Andrew Wigdor, email newseditor@mtsusidelines.com.

For more news, follow us at http://www.mtsusidelines.com, on Facebook at MTSU Sidelines and on Twitter at @Sidelines_News.

Original post:

Final MTSU Star Party of the semester hosted by physics, astronomy departments - Sidelines Online (subscription)

Photo: Courtesy Of UC Berkeley, Handout Photo

Harold Weavers discov ery led to a new science.

Harold Weavers discov ery led to a new science.

Harold F. Weaver, pioneer of radio astronomy at UC Berkeley, dies

Harold F. Weaver, a pioneering UC Berkeley astronomer whose discovery of radio emissions from molecules in outer space marked the new science of radio astronomy, has died at his East Bay home in Kensington. He was 99.

Nearly 60 years ago, Professor Weaver created the universitys first radio astronomy observatory at Hat Creek, a remote valley in Plumas County 290 miles from the Berkeley campus. The surrounding mountains shielded the observatory from interference by aircraft signals and the radio noises of civilization.

Its big receiver, a dish-shaped antenna, 85 feet in diameter, would lead to major discoveries and become the mainstay of the UC Radio Astronomy Laboratory, which Professor Weaver had founded on the Berkeley campus in 1958. He would direct it for the next 15 years.

At their Hat Creek observatory, Professor Weaver and his colleagues discovered the existence of astrophysical masers the equivalent in outer space of the lasers that had been created eight years earlier by UC Berkeleys Nobel laureate physicist Charles Townes. The masers were the first evidence that objects in the gas clouds of the galaxy were emitting coherent radiation.

Professor Weaver would later discover the first interstellar molecules known as hydroxyl radicals at a time when their mysterious radio emissions were often attributed to an unknown form of space matter named mysterium. Since his discovery, many other interstellar molecules have been detected in the atmosphere of comets.

His curiosity about the universe was wide: Even as a young astronomer on the Berkeley faculty in 1953 he was using galactic star clusters and Cepheid variable stars to calculate the outer limits of the Milky Way galaxy and to estimate that the universe was at least 3.6 billion years old close to todays estimates of 4 billion years.

Ten years later, he and the late Martin Schwartzchild of Princeton University launched a giant balloon from Palestine, Texas, in a project called Stratoscope. A 2-ton telescope carried by the balloon to an altitude of 15 miles peered at Mars and discovered the worlds first evidence of water vapor in the Martian atmosphere before it crashed in a mud-filled Louisiana cow pasture.

Harold Francis Weaver was born in San Jose in 1917, and by high school he was already building his own telescopes.

Still, he debated whether he would study classics or astronomy in college. The poet Robinson Jeffers had a telescope in his Carmel home, and encouraged the young man in his telescope-building interests.

As a UC Berkeley undergraduate in the astronomy department, he met his future wife, Cecile Trumpler, the daughter of astronomer Robert Julius Trumpler, and the two were married in 1939. It was Professor Trumpler who supervised his doctoral dissertation, and the two later collaborated on a book called Statistical Astronomy, which was published in 1953 and is still in use.

During World War II, he was conscripted to work on optics research for the National Defense Research Committee and later worked on isotope separation at what was then known as the Berkeley Radiation Lab.

After the war, he served as a staff scientist at Lick Observatory and joined the astronomy faculty at UC Berkeley in 1951. He retired as a professor in 1988 after publishing more than 70 professional papers and helping to guide development of the expanding Berkeley campus as a member and chairman of the Campus Facilities Committee in the 1950s and 1960s. He helped design the astronomy departments Campbell Hall, which was recently demolished and rebuilt on the same site.

Harold was truly a giant in our department of astronomy, UC astronomy Professor Alex Filippenko said after Professor Weavers April 26 death. I will always remember his warm smile, his generosity, and how he kept going with his research and other activities well into old age.

Professor Weaver had long served as treasurer both of the American Astronomical Society and Astronomical Society of the Pacific, and was a member of the group that founded the Chabot Space and Science Center in Oakland, where he served on the board of directors for many years.

He was also interested in contemporary writing, and for many years served as treasurer and a director of the Squaw Valley Community of Writers, a summer creative writing project located near Lake Tahoe.

The Weavers have donated their longtime Kensington home to UC to be used after their deaths to fund the Trumpler-Weaver Endowed Professorship in Astronomy at UC Berkeley.

Professor Weaver is survived by his wife and three children, Margot of Tucson, Paul of Kensington and Kirk of Houston.

Memorial gifts may be made to the Cal Alumni Leadership Award in care of the California Alumni Association, 1 Alumni House, Berkeley, CA 94720.

A memorial service is being arranged.

David Perlman is The San Francisco Chronicles science editor. Email: dperlman@sfchronicle.com

More here:

Harold F. Weaver, pioneer of radio astronomy at UC Berkeley, dies - SFGate