Category Archives: Astronomy

'Oumuamua, the cigar-shaped object from another solar system that whizzed through our own in 2017, continuesto perplex astronomers. Its inexplicable properties have prompted some to propose that the object was an alien craft of some sort, while other astronomers are steadfast in their insistence that it had natural origins.

Now, there's a new chapter in the saga of this mysterious 650-foot-long tube-shaped object. Earlier this year, researchers at Arizona State University published a new study claiming to "resolve" the mystery surrounding 'Oumuamua (pronounced "oh moo ah moo ah").

Published inJournal of Geophysical Research: Planets, the researchers statedin a pair ofpapers that 'Oumuamua was likely a nitrogen ice ball, perhaps from a planet like Pluto yet in another solar system not an artificially made light-sail spacecraft, comet, or interstellar ball of dust, as some researchers have previously suggested. Nitrogen, the primary component of Earth's atmosphere, occurs primarily as a gas on our home planet; yet in very cold conditions, it can freeze and become solid or liquid. The frigid surface of Pluto, for instance, contains a substantial amount of nitrogen ice.

'Oumuamua's characteristics, the Arizona State University researchers argued, suggested the strange object boresimilarities to the surface of Pluto.

"This research is exciting in that we've probably resolved the mystery of what 'Oumuamua is and we can reasonably identify it as a chunk of an 'exo-Pluto,' a Pluto-like planet in another solar system," said Steven Desch, an astrophysicist at Arizona State University and an author of the new study,in March 2021. "Until now, we've had no way to know if other solar systems have Pluto-like planets, but now we have seen a chunk of one pass by Earth."

Previously in 2020, in a separate paper published by a different group of scientists, researchers argued that 'Oumuamua was actually a hydrogen iceberg a similar proposal to the nitrogen iceberg theory of the Arizona State researchers.

But if you thought thescientific world was closing the book on'Oumuamua or at the very least coming to peace with the idea that the interstellar object was of natural origin (and not alien made) not everyone agrees with the Arizona State researchers. Multiple papers co-authored by Harvard physicistAvi Loeb have argued that it is unlikely that 'Oumuamua was a hydrogen iceberg, or a nitrogen one for that matter.

In a series of co-authored papers and a book, Loeb believes the most likely explanation is that Oumuamua was artificially made perhapssome sort of light sail made by an alien civilization.

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"I would say that the [idea it is of] artificial origin appears to me is quite likely and it should definitely be considered in the future," Loeb told Salon. "Of course, what we want to do is find more objects of that same type, and then catch them early enough on the approach to us so that we can send a spacecraft that will intercept the trajectory and take a close up photograph."

Loeb'slatest co-authored paper, which has yet to be peer-reviewed, argues'Oumuamua definitively was nota piece of a Pluto-like exoplanet or a glob of hydrogen ice. To disprove this, Loeb and his fellow researchers calculatedhow cosmic rays background radiation that constantly permeates empty space would have slowly caused such an "iceberg"to evaporate over millions of years of travel. If 'Oumuamua were comprised of such exotic ice, Loeb and his co-authors calculate that significantcosmic ray erosion would have whittled it down during its journey.

Simply put, Loeb doesn't believe there's enough hydrogen or nitrogen in nearby planets that could have accumulated to being 'Oumuamua's hypothetical original size.

Loeb stressed that we have never seen something like a hydrogen or a nitrogen "iceberg" drifting through space. If 'Oumuamura were such a thing, it would have to have originated from very nearby to avoid evaporating due to erosion.

"Those environments need to be close enough to us, or at least closer than a percent of the size of the Milky Way Galaxy, because otherwise these chunks would entirely evaporate," Loeb said. "The solar system or whatever produces them must be a very different environment."

Loeb does not rule out a natural (non-alien)origin for 'Oumuamua, but said that the numbers don't add up for something that was made of nitrogen.

"Arguing that it's a nitrogenous base to me, now that we did this calculation of the cosmic rays evaporating it makes it very unlikely," he added.

Indeed,the clash over theories of 'Oumuamua's composition and origins arecausing some tension among astrophysicists.

Part of the debate, as Loeb alludes to, stems from observations of the object's odd behavior when it was first discovered in October 2017. Back then,a postdoctoral researcher named Robert Weryk at the University of Hawaii was sifting through the data stream from the Pan-STARRS astronomical survey of the sky when he noticed an unexpected object. It appeared to be highly elongated, like a stick, with a long axis 10 times longer than its short axis unprecedented for an asteroid.

Upon a further analysis, researchers found that it appeared that 'Oumuamua received an unexpected "push" from the sun as it left our solar system as though it had a mirror or a sail of some kind that it was using for propulsion. The manner of its push resembled what one might see from a solar sail spacecraft, a type of proposed interstellar probe propulsion that humans actually tested with an experimental probe in 2010.

In any case, no one had ever seen anything 'Oumuamua at the time that it was first observed. Some scientists hypothesized that 'Oumuamua swung towards our solar system as a result of a gravitational slingshot of a binary star system; others postulatedthat it might be an odd comet, though no tail was evident. Thus the search began to collect and analyze as much data as possible before it left our solar system.

Loeb, who wrote a book about 'Oumuamua entitled "Extraterrestrial: The First Sign of Intelligent Life Beyond Earth,'' continues to believe that the only possible explanation (unless the data was wrongly collected) is that Oumuamua was something akin to a light sailspacecraft created by an extraterrestrial civilization.

Loeb's idea has understandably sent shockwaves through the scientific community and stoked controversy. Mostastronomers coalescedaround the idea that 'Oumuamua was of natural origin, rather than artificial.

In an interview, Desch told Salon Loeb's most recent paper was yet another "attack" on any explanation that 'Oumuamua was a naturally made object.

"We took great pains to make sure we were comprehensive about all the data that existed and we took into account everything . . .we're careful about it, and went through the peer review process, and I stand by our work," Desch said, adding that Loeb's paper doesn't include findings that suggest cosmic ray erosion is slower than they suggest in their calculations. "I can tell you that the experiments say [cosmic ray erosion] is a lot slower than he's saying in fact we cited those experiments and in this case they are just basically are saying, 'well, all of the energy of the cosmic rays can be used to erode the ice, but the experiments show that that's just not true.'"

Desch emphasized: "If you took a chunk of Pluto and you knocked it off and made it go by the sun, it would look, move and behave exactly as this object did."

Over the last couple of years, Loeb has been encouraging the scientific community to change and be more "open-minded to change." In Loeb's perspective, the idea that'Oumuamua was artificially made has notbeen as widely embraced as the various ideas that it is of natural origin.

Desch said that most astronomers believe there are aliens out there, but do not believethat 'Oumuamua wasn't a sign of extraterrestrial life.

"If you ask almost any astrophysicist, 'Do you think there are aliens out there?' Almost 100% would say, 'somewhere in the universe, it's a really big place but [it's] really hard for them to get here,'" Desch said. "But this thing? No, this is a snowball."

Loeb rebuffed Desch's "snowball" theory for 'Oumuamua's properties.

"We did the calculations from first principles," Loeb said of his research. "[Desch]underestimated the evaporation by cosmic rays in his paper."

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The once-sedate astronomy world is quarreling over whether 'Oumuamua was an alien craft - Salon

Uzbekistan has embarked on a journey to identify, catalogue and showcase all art objects reflecting the country's cultural heritage that are scattered around the world. Once at the centre of the Great Silk Road, Uzbekistan has an important cultural inheritance.

The most recent meeting from the initiative, named Cultural Legacy of Uzbekistan in the World Collections, brought together around 350 scientists from all over the world and was the key event of Uzbekistans Cultural Heritage Week.

The first true-to-the-original facsimile copy of the manuscript of Images of the Fixed Stars was also presented at the initiative. The book is the work of one of the most famous Muslim astronomers of all time, Abd al-Rahman al-Sufi, and it was commissioned by the special order of Mirzo Ulugbek, better known as Ulugh Beg, a Timurid dynasty (Sunni Muslim) sultan. Ulugh Beg was also a respected astronomer and mathematician.

The ancient manuscript, which has now been turned into a book, has historical significance because of several reasons: it is living proof of the centuries-old fascination of the firmament, the golden age of Islamic science, and the antiquity of the Arabic tradition in astronomy, to name a few.

The book is hailed as a masterpiece of Central Asian art: it has 74 fascinating miniatures of constellations executed using the finest technique. It also marks the trend where illustrated manuscripts were increasingly produced and is one of the oldest surviving treatises of its kind. The manuscript contains miniature illustrations depicting the sultan in the form of the constellation Cepheus.

Beyond its artistic value, the book also holds enormous scientific importance. The work, containing 48 constellations known as the Fixed Stars, is based on knowledge of the stars transmitted by the Greeks but includes the principles of ancient Arab astronomy for the first time.

Before Abd al-Rahman al-Sufi, the first known attempts to describe the starry sky were done by the Greeks. By Ptolemy (100-160), to be precise, who was an ancient philosopher, mathematician and astronomer from Alexandria. His writings were regarded as the standard scientific work on celestial science up to the early modern age. His most important work was Almagest a systematic guide to mathematical astronomy, which was the main reference for centuries until Abd al-Rahman al-Sufi came on the scene.

Al-Sufis work on the fixed stars was based on the Almagest by Ptolemy, but he corrects various statements and supplements them with his own empirical conclusions. He took all the star names mentioned in Ptolemys catalogue of stars and merged them with the ones mentioned in Arabic literature.

In his observations, Al-Sufi added the earliest known descriptions and illustrations of the Andromeda Galaxy and also the first recorded mention of the Large Magellanic Cloud - the first galaxies other than the Milky Way to be observed from planet Earth.

In the astronomer's book, all the mythological figures representing the constellations are depicted as seen in the sky but also as seen from space. And thanks to this, his work served for many centuries as the most important guide to the stars both in the Islamic and also Christian world.

The original manuscript for the book of the Images of the Fixed Stars did not survive, however, thanks to the Islamic manuscript tradition, Al-Sufis work lived on in copies that were made after.

The contemporary facsimile version being presented at the Cultural Legacy of Uzbekistan in the World Collections is the result of Uzbekistans goal to use advanced scientific technologies in the preservation of historical exhibits and manuscripts.

Dozens of other books devoted to Uzbek works have already been published as part of the initiative. And there is also work in progress on the digitisation and publication of facsimile copies of outstanding works preserved in libraries around the world.

UNESCO representatives have praised Uzbekistan for its initiative to preserve the rich historical and cultural heritage of the country. Renato Ramrez, Deputy Director-General for Culture of UNESCO said Uzbekistan was, in this matter an example for many countries. Research is a way of transferring not only academic knowledge but also knowledge for our children and new generations.

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Images of the Fixed Stars: Ancient astronomy manuscript resurrected by Uzbek heritage initiative - Euronews

The ConversationSep 20, 2021 13:15:57 IST

The James Webb Space Telescope is scheduled to head to space on Dec. 18, 2021. With it, astronomers hope to find the first galaxies to form in the universe, will search for Earthlike atmospheres around other planets and accomplish many other scientific goals.

I am an astronomer and the principal investigator for the Near Infrared Camera or NIRCam for short aboard the Webb telescope. I have participated in the development and testing for both my camera and the telescope as a whole.

he James Webb Space Telescope is the biggest orbital telescope ever built and is scheduled to be launched into space on Dec. 18, 2021. NASA/Desiree Stover,

To see deep into the universe, the telescope has a very large mirror and must be kept extremely cold. But getting a fragile piece of equipment like this to space is no simple task. There have been many challenges my colleagues and I have had to overcome to design, test and soon launch and align the most powerful space telescope ever built.

The Webb telescope has a mirror over 20 feet across, a tennis-court sized sun shade to block solar radiation and four separate camera and sensor systems to collect the data.

It works kind of like a satellite dish. Light from a star or galaxy will enter the mouth of the telescope and bounce off the primary mirror toward the four sensors: NIRCam, which takes images in the near infrared; the Near Infrared Spectrograph, which can split the light from a selection of sources into their constituent colors and measures the strength of each; the Mid-Infrared Instrument, which takes images and measures wavelengths in the middle infrared; and the Near Infrared Imaging Slitless Spectrograph, which splits and measures the light of anything scientists point the satellite at.

This design will allow scientists to study how stars form in the Milky Way and the atmospheres of planets outside the Solar System. It may even be possible to figure out the composition of these atmospheres.

Ever since Edwin Hubble proved that distant galaxies are just like the Milky Way, astronomers have asked: How old are the oldest galaxies? How did they first form? And how have they changed over time? The Webb telescope was originally dubbed the First Light Machine because it is designed to answer these very questions.

The NIRCam, seen here, will measure infrared light from extremely distant and old galaxies. NASA/Chris Gunn,

One of the main goals of the telescope is to study distant galaxies close to the edge of observable universe. It takes billions of years for the light from these galaxies to cross the universe and reach Earth. I estimate that images my colleagues and I will collect with NIRCam could show protogalaxies that formed a mere 300 million years after the Big Bang when they were just 2% of their current age.

Finding the first aggregations of stars that formed after the Big Bang is a daunting task for a simple reason: These protogalaxies are very far away and so appear to be very faint.

Webbs mirror is made of 18 separate segments and can collect more than six times as much light as the Hubble Space Telescope mirror. Distant objects also appear to be very small, so the telescope must be able to focus the light as tightly as possible.

The telescope also has to cope with another complication: Since the universe is expanding, the galaxies that scientists will study with the Webb telescope are moving away from Earth, and the Doppler effect comes into play. Just like the pitch of an ambulances siren shifts down and becomes deeper when it passes and starts moving away from you, the wavelength of light from distant galaxies shifts down from visible light to infrared light.

Webb detects infrared light it is essentially a giant heat telescope. To see faint galaxies in infrared light, the telescope needs to be exceptionally cold or else all it would see would be its own infrared radiation. This is where the heat shield comes in. The shield is made of a thin plastic coated with aluminum. It is five layers thick and measures 46.5 feet (17.2 meters) by 69.5 feet (21.2 meters) and will keep the mirror and sensors at minus 390 degrees Fahrenheit (minus 234 Celsius).

The Webb telescope is an incredible feat of engineering, but how does one get such a thing safely to space and guarantee that it will work?

The James Webb Space Telescope will orbit a million miles from Earth about 4,500 times more distant than the International Space Station and much too far to be serviced by astronauts.

Over the past 12 years, the team has tested the telescope and instruments, shaken them to simulate the rocket launch and tested them again. Everything has been cooled and tested under the extreme operating conditions of orbit. I will never forget when my team was in Houston testing the NIRCam using a chamber designed for the Apollo lunar rover. It was the first time that my camera detected light that had bounced off the telescopes mirror, and we couldnt have been happier even though Hurricane Harvey was fighting us outside.

After testing came the rehearsals. The telescope will be controlled remotely by commands sent over a radio link. But because the telescope will be so far away it takes six seconds for a signal to go one way there is no real-time control. So for the past three years, my team and I have been going to the Space Telescope Science Institute in Baltimore and running rehearsal missions on a simulator covering everything from launch to routine science operations. The team even has practiced dealing with potential problems that the test organizers throw at us and cutely call anomalies.

n order to detect the most distant and oldest galaxies, the telescope needs to be huge and kept extremely cold. NASA/Chris Gunn,

The Webb team will continue to rehearse and practice until the launch date in December, but our work is far from done after Webb is folded and loaded into the rocket.

We need to wait 35 days after launch for the parts to cool before beginning alignment. After the mirror unfolds, NIRCam will snap sequences of high-resolution images of the individual mirror segments. The telescope team will analyze the images and tell motors to adjust the segments in steps measured in billionths of a meter. Once the motors move the mirrors into position, we will confirm that telescope alignment is perfect. This task is so mission critical that there are two identical copies of NIRCam on board if one fails, the other can take over the alignment job.

This alignment and checkout process should take six months. When finished, Webb will begin collecting data. After 20 years of work, astronomers will at last have a telescope able to peer into the farthest, most distant reaches of the universe.

Marcia Rieke, Regents Professor of Astronomy, University of Arizona

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Astronomer on James Webb telescope team explains how and why we are sending a giant telescope to space? - Firstpost

The first four space adventurers of the Insperation4 mission landed last night in the Atlantic Ocean off the coast of Florida after spending three days in space aboard SpaceXs Crew Dragon shuttle, successfully completing the first orbital mission in history without professional astronauts. The ditching happened on time, just after 7 PM local time. Four large parachutes slowed the descent of the capsule, which was quickly recovered from the SpaceX ship. Passengers will then be flown by helicopter to the Kennedy Space Center, where the shuttle blasted off with a Falcon 9 rocket on September 15.

The missions stated goal was to make a breakthrough in the democratization of space, demonstrating that the universe was accessible even to crews who had not been selected and trained in years. The four newbies billionaire Jared Isaacman, who chartered the mission, and three other Americans spent three days in Earth orbit, past the International Space Station (ISS), at an altitude of up to 590 kilometers. They broke orbit at 28,000 kilometers per hour, and they traveled around the world more than 15 times a day.

This is the third time Elon Musk, who has become a giant in the space sector in a few years, has returned a human to Earth: during previous missions on behalf of NASA, six astronauts had already suffered a crash on the same shuttle, in their case after Accommodation at the International Space Station.

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SpaceX, the Four Space Adventurers - Space and Astronomy are back on Earth - News Net Nebraska

Ceres at opposition on November 27. Now begins the best time in 2021 to observe it. Heres a Dawn spacecraft view of Ceres in false color. Those bright spots on the dwarf planets surface caused a stir when Dawn first spied them on approach to Ceres in 2015. Image via NASA/ JPL-Caltech/ UCLA/ MPS/ DLR/ IDA.

Ceres was the first asteroid discovered, in 1801. The International Astronomical Union reclassified it and Pluto as dwarf planets in 2006. Ceres is the largest object in the asteroid belt between Mars and Jupiter. Its the only world in the asteroid belt with enough mass and therefore enough self-gravity to pull itself into the shape of a ball. So Ceres is the only dwarf planet in the asteroid belt, or even inside the orbit of Neptune, for that matter. In 2021, Ceres will be at opposition opposite the sun in our sky on November 27. At that time, itll rise at sunset and set at sunrise. Its coming up later at night now (mid-September), but will be rising earlier. Now is the beginning of the best time in 2021 to view Ceres.

Ceres is about 600 miles (1,000 km) across, or about 1/4 the size of our moon. With its size wedged somewhere between an asteroid and a planet, Ceres was a target for study by the Dawn spacecraft.

Dawn arrived at Ceres in 2015. The spacecraft caused a stir while approaching Ceres, when it began to capture images of bright spots on the dwarf planets surface. People joked that the spots looked like alien headlights. But they turned out to be salt deposits from salty water inside the planet. Dawn also found a 2.5-mile (4,000-meter) high mountain named Ahuna Mons.

If you have a telescope or good binoculars, now is the time to start watching Ceres. Note that the name asteroid means starlike. From Earth, Ceres looks like a star. But because its so close to us, it can be seen to move in front of the stars from night to night.

So dust off your binoculars or telescope and head to a dark-sky site to see Ceres. The brightness of astronomical objects is measured in something called magnitude, with lower numbers indicating brighter objects. From a location free of light pollution, you can see objects down to about magnitude 6. Right now (September), Ceres shines around magnitude 8. But Ceres at its brightest in 2021 (late November) will shine around magnitude 7. So you can see youll need optical aid to bag this unique object. Ceres is brightening as it nears opposition!

Ceres is now moving in front of the constellation Taurus the Bull. Itll remain in front of Taurus between now (mid-September 2021) and the time of its opposition (November 27, 2021). In fact, Ceres will spend much of fall 2021 cutting across the V-shaped Hyades star cluster in Taurus. Itll be near the bright reddish-orange star Aldebaran, brightest star in Taurus.

November 6-7 might be the date in 2021 that Ceres is easiest to find. Magnitude 7.5 Ceres will be just 10 arcminutes from Aldebaran in Taurus around then. That distance on our skys dome 10 arcminutes is about 1/3 the width of a full moon. Its about 1/6 the width of your pinky held at arms length. Either way, if you focus binoculars or a telescope on Aldebaran, the point of light just to the northeast of the star will be Ceres.

Ceres orbits our sun at a greater distance than Earth. Its average distance from the sun is about 2.77 times that of the Earth. And so Ceres brightness doesnt vary much throughout the year. Being small, far away and dim, it requires at least binoculars to spot and even then it only appears as a point of light like a distant star.

Ceres does us no favors in terms of its reflectivity. Objects have a measurement called albedo, which is a number between 0 and 1 for how black or white they are. Very reflective fresh snow or ice can have an albedo of 0.8 or 0.9. Our neighboring planet Venus is often said to appear bright to us because its thick cloud cover reflects so much sunlight. Venus has an albedo of 0.65. On the other hand, low-albedo objects absorb most sunlight and are quite dark. Charcoal and fresh asphalt both score a 0.04 for their albedo. Ceres albedo is 0.07. Its practically hiding in the dark against the blackness of space.

Ceres may be the brightest dwarf planet, but only because it lies within the asteroid belt, the zone of solar system debris between Mars and Jupiter. Plutos albedo is 0.30 and Eris is 0.86, one of the highest albedos in the solar system. Ceres is only about three times farther from the sun than Earth. Compare that to Pluto, which is 40 times farther from the sun than Earth. And Eris is a whopping 68 times farther from the sun.

Bottom line: With Ceres at opposition November 27, the dwarf planet is closest to Earth and therefore brightest, making it a great time to observe. Ceres will be near Aldebaran around November 6 and 7.

Kelly Kizer Whitt has been a science writer specializing in astronomy for more than two decades. She began her career at Astronomy Magazine, and she has made regular contributions to AstronomyToday and the Sierra Club, among other outlets. Her childrens picture book, Solar System Forecast, was published in 2012. She has also written a young adult dystopian novel titled A Different Sky. When she is not reading or writing about astronomy and staring up at the stars, she enjoys traveling to the national parks, creating crossword puzzles, running, tennis, and paddleboarding. Kelly lives with her family in Wisconsin.

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Ceres at Opposition on November 27 - EarthSky

If theres one thing you learn when you study astronomy, its do NOT screw around with black holes.

100 million light years from Earth lies a galaxy called NGC 5813. Its part of a small galaxy group, a collection of a few dozen other galaxies. When viewed in visible light NGC 5813 looks like any other elliptical galaxy: An elongated puffball with a few hundred billion stars in it.

But it has a supermassive black hole in its heart, one that tips the cosmic scales at 700 million times the mass of the Sun. When you pack hundreds of millions of times the mass of a star into a volume smaller than our solar system youre dealing with tremendous, mind-crushing forces, phenomena powerful enough to create chaos on a vast scale.

Matter falling into the maw of this monster forms a flat, swirling disk, heated to millions of degrees. Magnetic fields wrap up like tornadoes, ripping material away from the disk and accelerating it to nearly the speed of light above and below the disk. These jets, as astronomers call them, are events of incredible power.

For example: There is a thin gas that fills the space between the galaxies in the group. In the past, and even now, the black hole in NGC 5813 has had epic, colossal eruptions, creating jets that have blasted outward and plowed through that gas. Over the past 100 million years this has happened three times, the twin jets punching into the gas and creating enormous cavities in it.

Deep images taken by the Chandra X-ray Observatory show on just how large a scale this has occurred.

That image shows the hot gas surrounding NGC 5813, which would normally look fairly featureless. However, you can see three sets of cavities blown into the gas. The inner ones make the gas look like a figure-8, although one about 20,000 light years end-to-end. The next set outwards is twice that size, and the ones at the outer edge are about 100,000 light years away from the center thats nearly the size of our Milky Way galaxy.

The inner two pairs were known from earlier observations, but this extraordinarily deep X-ray image a total of about 630,000 seconds, a solid week shows the outer pair for the first time.

How much energy does it take to create such structures? The total power needed for the outer two pairs is something like the energy emitted from an entire galaxy for one hundred thousand years. Each. Thats equivalent to the energy the Sun emits for a hundred quadrillion years.

Again, each.

The inner cavities are interesting. In their research paper about this, astronomers calculate that the power needed to make them is only about one-tenth as much as the outer ones. Assuming each eruptive event from the black hole is equal (a decent idea) then that means this event is still ongoing, and were seeing it relatively early on.

What they think is happening here is that a relatively short-lived event caused the black hole to create the jets, which then slam into the gas, creating immense shock waves thousands of light years across, which in turn heat the gas hugely. This creates the cavity, which is hotter and less dense than the gas around it so it rises, that is, moves away from the black hole. That means the oldest cavities are the ones farthest out.

Not surprisingly, this can have ramifications for the entire galaxy. For example, gas in the galaxy can collapse to form stars, but only if its cool enough. If its too hot the pressure from the gas overcomes its own internal gravity.

Looking at the temperature and density of the gas in NGC 5813, the astronomers calculate that the heat pumped into it from the jets easily balances the rate at which the gas naturally tries to cool, which means this gas cannot collapse to form stars. It will stay hot and turbulent for as long as the black hole keeps episodically erupting.

Again, Ill remind you that this is all powered by a single object smaller than our solar system. Yet it can disrupt everything around it on a galactic scale.

The Milky Way has a black hole in its center, too. Called Sgr A* (Sagittarius A star), its only about 4 million solar masses, seriously underweight for a galaxy our size. That means it probably cant perform stunts like NGC 5813s black hole, at least not on this scale. At the moment its not actively feeding anyway, so were safe for now. And even if it were to start gobbling down matter and erupting, its unlikely to be anything this powerful.

Still, studying galaxies like NGC 5813 will help us understand how black holes interact with their environment and what kind of feedback they provide into their host galaxies. We know that these supermassive black holes play a critical role as galaxies are born, grow, and change over the eons, so studying them is important in our understanding of the greater Universe.

But sometimes, when I see Sagittarius rising over the horizon, I cast my eye toward the Milky Ways center that lies in that direction, and wonder about our own black hole. Did it once blast out soul-numbing amounts of energy, creating jets and cavities and X-ray emission visible from hundreds of millions of light years away?

The answer is almost certainly yes, but it was long, long ago. And for that Im happy.

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A supermassive black hole that can't stop erupting - SYFY WIRE

Does Earth's solar system host eight planets or nine?

The answer depends on who you ask. Ever since Pluto got demoted as a planet, a group of scientists still believe there is a ninth planet out there, somewhere. The evidence for it aboundsin our solar system: the weird orbits of a bunch of distant objects near Pluto hint that something massive is perturbing them.

The challenge is that nobody has been able to directly observe Planet Nine. That's not entirely surprising: given its likely distance from our sun, it would be incredibly dim.

But as with dark matter and dark energy, one's inability to observe something doesn't mean it doesn't exist.

Now, a new study re-examines oldobservations, and calculates new ones,suggesting that Planet Nine has a higher likelihood of being a real planet in an icy, faraway part of our solar system but closer than previously thought.

The study, published in the preprintarXivlast month and recentlyaccepted for publication by the Astronomical Journal, suggests there is only a 0.4 percent chance that Planet Nine is a statistical fluke. This new calculation is based on both more recent observations and old evidence that made the case for Planet Nine in the first place.

In addition to this calculation, the new study provides astronomers with a map of its orbit, and someof the best places in the sky to look for it. Its orbit was inferred by looking at the way that other objects in the outer solar system have their own orbits seemingly perturbed by some other massive object.The new proposed orbit suggests the hypothetical planet is closer to the sun than previously believed, which could make it easier for astronomers to spot. The predicted mass was also revised: based on new observations,Planet Nine is projected to be onlysix times the mass of Earth, instead of 20 times the size.

"By virtue of being closer, even if it's a little less massive, it's a good bit brighter than we originally anticipated,"co-author of the study Michael Brown, a professor of planetary astronomy at the California Institute of Technology, told NBC News. "So I'm excited that this is going to help us find it much more quickly."

According to National Geographic, Brown estimates Planet Nine is "within a year or two from being found."

However, Brown admitted: "I've made that statement every year for the past five years. I am super-optimistic."

Meanwhile, in a blog post, Brown further explained that several factors have changed since he and his colleagues first proposed the idea of Planet Nine. First, Brown argues there's a better understanding of how Planet Nine could affect objects around it. Second, hesays scientists have a better understanding of the observations that have been made over the last few years. Third, thanks to various numerical simulations, Brown and his team "understand how changes to parameters of Planet Nine change the outer solar system." And finally, thanks to a new mathematical model, scientists "now have probability distributions of all of the Planet Nine parameters."

The new paper is sure to stir a bit of a controversy in astronomy circles. Previously, speculation as to what was messing with the orbits of distant trans-Neptunian bodies fixated on the existence of a massive object although such an object does not necessarily have to be a planet.

In 2019, a separate paper proposed a very different theory behindPlanet Nine. Then, astronomers asked:what if Planet 9 were not a planet at all, but rather a primordial black hole as in,a hypothetical type of small black hole that formed soon after the Big Bang, in the early Universe, as a result of density fluctuations? Such a novel idea might have explained why powerful telescopes have never detected so much as a flicker from the theoretical distant planet. Likewise, black holes do not emit visible light at all; rather, they absorb all photons that pass their event horizon, while occasionally emitting energy in the form of (theorized but never directly observed) Hawking Radiation.

However, Brown is hopeful thattheVera Rubin Observatory, which currently under construction atop a Chilean mountaintop, will be able to discover Planet Nine when it is available to astronomers in 2023.

For the unfamiliar, astronomers believe that Planet Nine exists in part because a handful of objects in the Kuiper Belt appear to be clustered in the same orientation in space. This could be random, butthe pattern observed to these objects' orbits makes itmore likely to be the resultofthe gravitational force of an elusive, massive object hence, Planet Nine.

However, critics have often said "observation bias" could be the truth behind Planet Nine. In Brown's blog post, he admits "bias is real," but also notes, "I am here to show you that it doesn't cause the clustering that we see."

As Brown explains: "There is a lot of bias, and the observations generally fal[sic] along the lines of bias. But the bias clearly cannot account for the fact that the orbits are tilted and that they are tilted in one direction."

If discovered, it will be the first planet in our solar system to be found since Neptune in 1846. Similar to Planet Nine, astronomers discovered Neptuneusing mathematicsafter noticing Uranuswas being pulled slightly out of orbit by an unknown body. Astronomers were able to infer how much mass the unknownplanet had, and then where to look.

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Astronomers think they know where to find Planet Nine - Salon

The Subaru Telescope, an 8.2-meter diameter optical and infrared telescope located in Hawai`i, is the flagship facility of Japanese astronomy. Since 2000, an ever-evolving instrument suite keeps the Subaru Telescope on the cutting edge of science. It has been used by over 17,000 researchers to produce high-quality results including 156 PhD theses. In terms of citations, 16% of scientific papers using the Subaru Telescope rank in the top 10% of papers; and over 3% of Subaru Telescope papers rank in the top 1%.

In the coming decades, results from extremely large telescopes will change the way we think about humanitys relationship to the Universe. But as organisations around the world race to build larger telescopes, they face a trade-off. Larger telescopes have innately smaller fields of view, meaning the portion of the sky that can be captured in one observation. Simply put, extremely large telescopes will see an extremely small area extremely well. But without a comprehensive and accurate map of potential targets, these enormous telescopes will spend all their time staring at empty space, hoping for something interesting. Figuring out where to point a telescope to do the best research can be a difficult question.

The Subaru Telescope is and will continue to be the best telescope in the world for creating maps to guide future extremely large telescopes. Utilising a unique four foci design, the Subaru Telescope is able to side-step the size vs. field-of-view trade-off, achieving by far the largest field of view of any 8-metre class telescope. To make the best use of this advantage, we developed Hyper Suprime-Cam (HSC), one of the worlds largest digital cameras (shown in photo). HSC uses 870 megapixels to capture an area nine times the size of the full moon. This wide field of view is important to create cosmic maps.

The Subaru Telescopes wide field of view and high sensitivity also provides an unparalleled advantage for quickly finding the optical counterpart of gravitational wave or neutrino burst events, which involve instantaneous releases of unimaginable amounts of energy. The progenitors of these events evolve quickly after the outburst, but they are difficult to locate exactly for further study. The Subaru Telescope can cast a wide net to find them before they change too much. This is the paradigm of the emerging field of multi-messenger astronomy: observations of the same event in electromagnetic waves, ranging from radio to gamma rays, are combined with observations of non-electro-magnetic messengers such as gravitational waves or neutrinos to build a comprehensive picture of the Universe.

Soon, the Rubin Observatory Simonyi Survey Telescope will start observations with a field of view even wider than the Subaru Telescope. However, the Subaru Telescope will continue to offer observational capabilities not available at Rubin Observatory. Most notably, the Prime Focus Spectrograph (PFS) can simultaneously observe up to 2400 astronomical targets across a field of view comparable to that of HSC. PFS observes spectra allowing astronomers to determine crucial information about an objects speed, distance, and chemical composition. Therefore, Rubin Observatory will be our synergetic collaborator.

In the coming decades, extremely large 30-metre class telescopes will revolutionise how we think about the Universe and humanitys place in it. At the National Astronomical Observatory of Japan (NAOJ) we are participating in the TMT (the Thirty Meter Telescope) project, along with the California Institute of Technology, the University of California, the National Astronomical Observatories of the Chinese Academy of Sciences, the Department of Science and Technology of India, and the National Research Council (Canada). Larger telescopes can see fainter objects, more distant objects, and finer details. Therefore, TMT will be an ideal facility to follow up on interesting objects found by the Subaru Telescope.

Twenty-first-century astronomy is founded on collaboration. There is collaboration across political boundaries to construct large-scale facilities like TMT. There is also a collaboration between research facilities and collaboration across the traditional boundaries between research fields.

The Universe is a marvellous science laboratory filled with naturally occurring phenomena that are impossible to reproduce on Earth. For example, we still have little direct observational data about dark matter and dark energy which dominate the Universe. To unlock the mysteries of the Universe, the Subaru Telescope is stimulating cross-disciplinary work combining astronomy, general relativity, life sciences, and informatics involving big data and Artificial Intelligence.

The Subaru Telescope has long collaborated with neighbouring facilities in Hawai`i like W.M. Keck Observatory and Gemini North. Going forward, the Subaru Telescope will engage in synergetic collaboration with diverse partners such as Rubin Observatory, TMT, and multi-messenger facilities. Looking to the space-based astronomy community, the Subaru Telescope has initiated collaboration with NASAs Nancy Grace Roman Space Telescope and ESAs Euclid space telescope.

These collaborations on the ground and with space go beyond simple coordinated observations and data exchange. It starts much earlier, in the planning stages, deciding what instruments to build, what programs to conduct, and setting the overall direction for world astronomy in the coming decades.

It is fitting that the Subaru Telescope, which is charting the course for us to explore the heavens, is located in Hawai`i, where Native Hawaiians have long practised wayfinding, the art of guiding double-hulled sailing canoes by the stars and other natural signs. As modern explorers, we are inspired by the courage and ingenuity of those early navigators. In addition to the Subaru Telescope being an active and respected member of the world scientific community, it is also a member of the local community. We place great value on maintaining an environment of mutual trust and respect with our neighbours.

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Subaru Telescope: A nexus of next generation astronomy collaboration - Open Access Government

Scientists have uncovered evidence that white dwarf stars - previously believed to be inert - may in fact simply be ageing much more slowly by burning hydrogen on their surface, challenging a major technique astronomers use to determine stellar ages.

Although the prevalent view of these stars is that they have burnt up their hydrogen, new research contradicts that assumption.

Observations by the Hubble Space Telescope suggests that white dwarfs can continue to undergo stable thermonuclear activity, according to the new paper published in Nature Astronomy.

Jianxing Chen, of the University of Bologna and the Italian National Institute for Astrophysics, who led the research, said: "We have found the first observational evidence that white dwarfs can still undergo stable thermonuclear activity. This was quite a surprise, as it is at odds with what is commonly believed."

Because white dwarf stars are some of the oldest stellar objects in the universe, they offer scientists a good way to estimate the age of neighbouring stars.

But the new discovery could prompt a reassessment of how old some of the stars in the Milky Way are, as it means the cooling rate of a white dwarf is not necessarily the infallible clock it was once assumed to be.

At their core these stars are solid and made of oxygen and carbon due to what is called a phase transition - similar to water turning into ice, only at much higher temperatures.

Scientists have directly observed evidence of white dwarfs cooling into giant crystals.

Researchers at the University of Warwick believe our skies are filled with these enormous crystals, according to observations made with the European Space Agency's Gaia satellite.

Roughly 98% of all of the universe's stars will complete their lifecycles as white dwarfs, including our own sun, while more massive stars will collapse into neutron stars and black holes.

Astronomers have now compared cooling white dwarfs in two massive collections of stars - the globular clusters M3 and M13 - using the Hubble Space Telescope.

Analysing these clusters at near-ultraviolet wavelengths, the team compared more than 700 white dwarfs and found M3 contained standard white dwarfs which are simply cooling stellar cores.

But they found that M13 contains two populations of white dwarfs.

One population is of standard white dwarfs but another group which has somehow managed to hold on to an outer envelope of hydrogen, meaning they burn for longer and cool more slowly.

The researchers compared their results with computer simulations and found that roughly 70% of the white dwarfs in M13 were burning hydrogen in these envelopes on their surfaces.

Francesco Ferraro, also of the University of Bologna and the Italian National Institute for Astrophysics, aid: "Our discovery challenges the definition of white dwarfs as we consider a new perspective on the way in which stars get old.

"We are now investigating other clusters similar to M13 to further constrain the conditions which drive stars to maintain the thin hydrogen envelope which allows them to age slowly."

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White dwarf stars are meant to be dead - but astronomers have just found some that are still alive - Sky News

Department of Physics

Grade 5: - 22,847 - 26,341 per annumFixed Term - Part TimeContract Duration: 24 monthContracted Hours per Week: 17.5Closing Date: 18-Sep-2021, 6:59:00 AM

The Department and role purpose

The Department of Physics at Durham University is one of the very best UK Physics departments with an outstanding reputation for excellence in teaching, research and employability of our students.

The Department of Physics is committed to building and maintaining a diverse and inclusive environment. It is pledged to the Athena SWAN charter, where we hold a silver award, and has the status of IoP Juno Champion. We embrace equality and particularly welcome applications from women, black and minority ethnic candidates, and members of other groups that are under-represented in physics. Durham University provides a range of benefits including pension, flexible and/or part time working hours, shared parental leave policy and childcare provision

The Astronomy research group are seeking to appoint a self-motivated and experienced Project Coordinator to provide a professional service in support of the Astrophysical Constraints On The Identity Of The Dark Matter project and to support the daily operations and the effective and efficient running of the research section.

The post holder will be a committed, enthusiastic professional who relates well to people at all levels. She/he will be expected to demonstrate a high level of initiative and be confident in dealing with diverse groups, including visiting researchers, Heads of Faculties, Departments and Colleges and research groups across the University.

The post holder will be expected to work flexibly to deliver effective administrative support and guidance to the Project, relevant Astronomy group staff and its stakeholders. Working closely with senior staff and colleagues, she/he will be required to assist with the fundamental and general Astronomy group administrative services, as well as assisting with data gathering for funding and project applications, organising events and research activities, creating and maintaining financial and publishing records. The role will also provide opportunities for the post holder to contribute to the development of new promotional materials and communication tools for the Astronomy group e.g. website and social media content.

The Astrophysical Constraints On The Identity Of The Dark Matter Project Coordinator will act as the first point of contact for enquiries and managing a wide range of internal and external enquiries from staff, partners and other stakeholders via email, telephone and face-to-face contact, taking an active decision-making role and using judgement on a day-to-day basis, providing advice, support and information.

The candidate would be expected to assist the Principal Investigator and other members of the Astronomy Senior Management Team, providing administrative support to ensure the smooth running of activities and to maximise effective use of academic staff time.

This role is an excellent opportunity for an administrator seeking to develop their experience and knowledge at both strategic and operational levels, and applications are invited from enthusiastic individuals looking to embrace a new challenge.

Core responsibilities:

Role responsibilities:

Person specification - skills, knowledge, qualifications and experience required

Criteria:E, D

Recruiting to this post

In order to be considered for interview, candidates must evidence each of the essential criteria required for the role in the person specification above (including those listed in the section Realising Your Potential Approach).

In some cases, the recruiting panel may also consider the desirable criteria, so we recommend you evidence all criteria in your application.

Please note that some criteria will only be considered at interview stage.

How to apply

We prefer to receive applications online.

Please note that in submitting your application Durham University will be processing your data. We would ask you to consider the relevant University Privacy Statement https://www.dur.ac.uk/ig/dp/privacy/pnjobapplicants/ which provides information on the collation, storing and use of data.

What you are required to submit

Please ensure that you submit all documentation listed above or your application cannot proceed to the next stage.

Contact details

For further information please contact; Linda Wilkinson, Research Manager l.a.wilkinson@durham.ac.uk

DBS Requirement:Not Applicable.

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Astronomy Project Coordinator job with DURHAM UNIVERSITY | 264788 - Times Higher Education (THE)