Tag: astronomy

A New Study Suggests That As A Star Begins To Die And Slowly Expands Outward, It Would Temporarily Light Up As It Eats The Worlds It Hosts

600 light years away, in the constellation of Auriga, there is a star in some ways similar to our Sun. It’s a shade hotter (by about 800° C), more massive, and older.

Oddly, it appears to be laced with heavy elements: more oxygen, aluminum, and so on, than might be expected. A puzzle.

Then, last year, it was discovered that this star had a planet orbiting it. A project called WASP – Wide Area Search for Planets, a UK telescope system that searches for exoplanets — noticed that the star underwent periodic dips in its light.

This indicates that a planet circles the star, and when the planet gets between the star and us, it blocks a tiny fraction of the starlight.




The planet is a weirdo, for many reasons… but it won’t be weird for too much longer. That’s because the star is eating it.

OK, first, the planet. Called WASP 12b, it was instantly pegged as an oddball. The orbit is only 1.1 days long! Compare that to our own 365 day orbit, or even Mercury’s 88 days to circle the Sun.

This incredibly short orbital period means this planet is practically touching the surface of its star as it sweeps around at over 220 km/sec!

That also means it must be very hot; models indicate that the temperature at its cloud tops would be in excess of 2200°C.

Not only that, but other numbers were odd, too. WASP 12b was found to be a bit more massive and bigger than Jupiter; about 1.8 times its size and 1.4 times its mass.

That’s too big! Models indicate that planets this massive have a funny state of matter in them; they are so compressible that if you add mass, the planet doesn’t really get bigger, it just gets denser.

In other words, you could double Jupiter’s mass and its size wouldn’t increase appreciably, but since the mass goes up, so would its density.

But WASP 12b isn’t like that. In fact, it has a lower density than Jupiter, and is a lot bigger! Something must be going on… and when you see a lot of weird things all sitting in one place, it makes sense to assume they’re connected.

In this case it’s true: that planet is freaking hot, and that’s at the heart of this mess. Heating a planet that much would not exactly be conducive to its well-being.

When you heat a gas it expands, which would explain WASP 12b’s big size. It’s puffy! But being all bloated that close to a star turns out to be bad for your health.

Astronomers used Hubble to observe the planet in the ultraviolet and found clear signs of all sorts of heavy elements, including sodium, tin, aluminum, magnesium, and manganese, as well as, weirdly, ytterbium*.

Moreover, they could tell from the data that these elements existed in a cloud surrounding the planet, like an extended atmosphere going outward for hundreds of thousands of kilometers.

This explains the peculiar high abundance of heavy metals in the star I mentioned at the beginning of this post; they come from the planet! But not for long.

Given the mass of the planet and the density of the stream, it looks like it has roughly ten million years left. At that point, supper’s over: there won’t be anything left for the star to eat.

In reality it’s hard to say exactly what will happen; there may be a rocky/metal core to the planet that will survive. But even that is so close to the star that it will be a molten blob of goo.

The way orbits work, the way the dance of gravity plays out over time, the planet itself may actually be drawn inexorably closer to its star. Remember, too, the star is old, and will soon start to expand into a red giant.

So the planet is falling and the star is rising; eventually the two will meet and the planet will meet a fiery death.

All in all, it sucks to be WASP 12b.

But it’s cool to be an astronomer!

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Pass it on: New Scientist

Sky Watching Tips And Tricks For Cold Northern Nights

For much of the contiguous United States this winter has been marked by perpetual ice, snow as well as the now infamous polar vortex.

Such conditions might make even the most committed stargazer think twice before venturing outdoors.

Stepping outside to enjoy a view of the constellation Orion, Jupiter or even just the waxing moon these frosty nights takes only a minute or two, but if you plan to stay outside longer, remember that enjoying the starry winter sky requires protection against the cold temperatures.




The best garments are a hooded ski parka and ski pants, both of which are lightweight and provide excellent insulation. And remember your feet.

Two pairs of warm socks in loose-fitting shoes are quite adequate; for protracted observing on bitter-cold nights wear insulated boots.

Reach for the binoculars

In weather like this, one quickly will realize the advantage of using a pair of good binoculars over a telescope.

A person who attempts to set even a so-called “portable” scope up in bitter temperatures or blustery winds might give up even before he or she got started.

But binoculars can be hand-held and will produce some quickly magnified images of celestial objects before rushing back inside to escape the frigidity.

Transparency

In their handy observing guide, “The Stars” (Golden Press, N.Y.), authors Herbert Zim and Robert Baker write that “the sky is never clearer than on cold, sparkling winter nights.

“It is at these times that the fainter stars are seen in great profusion. Then the careful observer can pick out dim borderline stars and nebulae that cannot be seen when the sky is less clear.

What Zim and Baker were referring to is sky transparency, which is always at its best during the winter season. That’s because Earth’s atmosphere is not as hazy because it is less moisture laden.

Cold air has less capacity to hold moisture, therefore the air is drier and thus much clearer as opposed to the summer months when the sky appears hazier.

But this clarity can also come at a price.

Seeing through the twinkles

If you step outside on one of those “cold, sparkling nights” you might notice the stars twinkling vibrantly.

This is referred to as scintillation, and to the casual observer looking skyward, they might think of such a backdrop as the perfect night for an astronomer, but it isn’t.

This is because when looking skyward, skywatchers are trying to see the sky through various layers of a turbulent atmosphere.

Were we to train a telescope on a star, or a bright planet like Mars, what we would end up with is a distorted image that either seems to shake or quiver or simply “boils” to the extent that you really can’t see very much in terms of any detail.

Forecasting sky conditions

If you own a telescope, you don’t need to wait for balmy summer nights to get good views. Usually, a few days after a big storm or frontal passage, the center of a dome of high pressure will build in to bring clear skies and less wind.

And while the sky might not seem quite as “crisp” or “pristine” as it was a few days earlier, the calming effect of less winds will afford you a view of less turbulent and clearer images through your telescope.

More comfortable nights ahead

If you plan on heading out on a cold winter’s night — and if you’re doing it while under a dome of high pressure — the fact that there is less wind means not only potentially good seeing, but also more comfort viewing conditions.

The end of winter is in sight though. The Northern Hemisphere is officially halfway through the winter season and milder, more comfortable nights are within reach.

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Pass it on: Popular Science

 

The Most Distant Supermassive Black Hole Ever Discovered

Scientists searching for astronomical objects in the early universe, not long after the Big Bang, have made a record-breaking, two-for-one discovery.

Using ground-based telescopes, a team of astronomers have discovered the most distant supermassive black hole ever found.

The black hole has a mass 800 million times greater than our sun, which earns it the “supermassive” classification reserved for giants like this.

Astronomers can’t see the black hole, but they know it’s there because they can see something else: A flood of light around the black hole that can outshine an entire galaxy.

This is called a quasar, and this particular quasar is the most distant one ever observed.




The light from the quasar took more than 13 billion years to reach Earth, showing us a picture of itself as it was when the universe was just 5 percent of its current age.

Back then, the universe was “just” 690 million years old. The hot soup of particles that burst into existence during the Big Bang was cooling rapidly and expanding outward.

The first stars were starting to turn on, and the first galaxies beginning to swirl into shape.

Quasars from this time are incredibly faint compared to the nearest quasars, the light from some of which takes just 600 million light years to reach the Earth.

Black holes, mysterious as they are, are among the most recognizable astronomical phenomena in popular science.

They’re pretty straightforward: Black holes are spots in space where the tug of gravity is so strong that not even light can escape.

They gobble up gas and dust and anything that comes near, growing and growing in size. A supermassive black hole sits in the center of virtually all large galaxies, including the Milky Way.

Astronomers can infer their existence by watching fast-moving stars hurtle around a seemingly empty, dark region.

Quasars, meanwhile, are a little trickier to understand, and you’d be forgiven for thinking they sound like something out of Star Trek.

A quasar is, to put it simply, the product of a binge-eating black hole. A black hole consumes nearby gas and dust inside a galaxy with intense speed, and the violent feast generates a swirling disk of material around it as it feeds.

The disk heats up to extreme temperatures on the order of 100,000 degrees Kelvin and glows brightly. The resulting light show is what we call a quasar, and what a light show it is.

The more material a black hole consumes, the bigger it becomes. Eventually, the black hole drains the surrounding area of material and has nothing to eat.

The luminous disk around it shrinks and fades, and the quasar is extinguished.

In this way, quasars—and the black holes that power them—are like volcanoes, erupting under one set of conditions and settling into dormancy under another.

Quasars were first detected in 1963 by the Dutch astronomer Maarten Schmidt with California’s Palomar Observatory.

Astronomers thought these newly discovered points of light were stars because of their extreme brightness.

But when they studied the spectrum of their light, they were stunned to find the “stars” were more than a billion light-years away.

When light travels through space, it gets stretched thanks to the constant expansion of the universe. As it moves, it shifts toward redder, longer wavelengths.

Astronomers can measure this “redshift” to figure out how long the light took to reach Earth, which indicates how far a certain object is.

Schmidt and his fellow astronomers knew that for stars to appear so luminous to Earth from such great distances was impossible. They were dealing with completely new phenomena.

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Pass it on: New Scientist

Planet Nine Could Be Our Solar System’s Missing ‘Super Earth’

Planet Nine is out there, and astronomers are determined to find it, according to a new statement from NASA. In fact, mounting evidence suggests it’s hard to imagine our solar system without the unseen world.

The hypothetical planet is believed to be about 10 times more massive than Earth and located in the dark, outer reaches of the solar system, approximately 20 times farther from the sun than Neptune is.

While the mysterious world still has yet to be found, astronomers have discovered a number of strange features of our solar system that are best explained by the presence of a ninth planet, according to the NASA statement.

There are now five different lines of observational evidence pointing to the existence of Planet Nine,” Konstantin Batygin, a planetary astrophysicist at the California Institute of Technology (Caltech) in Pasadena, said in the statement.




If you were to remove this explanation and imagine Planet Nine does not exist, then you generate more problems than you solve.”

“All of a sudden, you have five different puzzles, and you must come up with five different theories to explain them.

In 2016, Batygin and co-author Mike Brown, an astronomer at Caltech, published a study that examined the elliptical orbits of six known objects in the Kuiper Belt, a distant region of icy bodies stretching from Neptune outward toward interstellar space.

Their findings revealed that all of those Kuiper Belt objects have elliptical orbits that point in the same direction and are tilted about 30 degrees “downward” compared to the plane in which the eight official planets circle the sun.

Using computer simulations of the solar system with a Planet Nine, Batygin and Brown also showed that there should be even more objects tilted a whopping 90 degrees with respect to the solar plane.

Further investigation revealed that five such objects were already known to fit these parameters, the researchers said.

Since then, the astronomers have found new evidence that further supports the existence of Planet Nine.

With help from Elizabeth Bailey, an astrophysicist and planetary scientist at Caltech, the team showed that Planet Nine’s influence might have tilted the planets of our solar system

Which would explain why the zone in which the eight major planets orbit the sun is tilted by about 6 degrees compared to the sun’s equator.

Finally, the researchers demonstrate how Planet Nine’s presence could explain why some Kuiper Belt objects orbit in the opposite direction from everything else in the solar system.

Going forward, the researchers plan to use the Subaru Telescope at Mauna Kea Observatory in Hawaii to find Planet Nine, and then deduce where the mysterious world came from.

The most common type of planets discovered around other stars in our galaxy has been what astronomers call “super Earths” — rocky worlds that are larger than Earth but smaller than Neptune.

However, no such planet has yet been discovered in our solar system, meaning that Planet Nine could be our missing “super Earth,” the researchers said.

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Pass it on: New Scientist

Google’s AI Found An Overlooked Exoplanet

NASA has discovered an eighth planet around a distant star, which means we’re no longer the largest solar system we know of.

The discovery was made thanks to some artificial intelligence help from Google, which found the planet by scouring previously overlooked “weak” signals in data captured by the Kepler Space Telescope.

The newly found planet is located in the solar system around Kepler-90, a star about 2,500 light-years away from Earth that was previously discovered in 2014.

The Kepler Space Telescope has been searching the galactic sky for exoplanets, or planets outside our own Solar System, since it launched in 2009.

In order to sift through all the data that it’s captured since that launch, scientists usually look at the strongest signals first.




And that process has worked well enough so far. NASA has confirmed 2,525 exoplanets in that time, a number that has changed our understanding of how common it is to find planets around the stars that make up our galaxy.

Recently, though, artificial intelligence has become a more prominent tool in astronomy.

Scientists, including ones who work on the Kepler data, have increasingly turned to machine learning to help sort through typically lower-priority data to see what they might have missed.

In the process, they found an overlooked planet that’s now named Kepler-90i.

But while we now know that Kepler-90 has the same number of orbiting planets as our Sun, the solar system is a poor candidate in the search for extraterrestrial life or at least, life as we know it.

Kepler-90 is about 20 percent bigger and 5 percent warmer than our Sun. And its eight planets dance around the star in much closer orbits than the ones in our own Solar System.

In fact, their orbits are so comparatively small that seven of Kepler-90’s eight planets would fit in between the Earth and the Sun.

The discovery of Kepler-90i, came after NASA let Google train its machine learning algorithms on 15,000 signals from potential planets in the Kepler database.

The scientists then took the trained system and set it to work on data from 670 stars that were already known to have multiple planets, as they considered those to be the most likely hiding places.

The newly discovered planet in Kepler-90, along with one other found in the Kepler-80 solar system announced today, are the first NASA was able to confirm from these new results from Google’s AI.

The inclusion of machine learning in this process shouldn’t scare humans whose livelihood revolves around discovering and studying exoplanets, according to Chris Shallue, a senior Google AI software engineer who worked on the project.

What we’ve developed here is a tool to help astronomers have more impact,” Shallue said on a conference call about the news.

It’s a way to increase the productivity of astronomers. It certainly won’t replace them at all.

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Pass it on: Popular Science

NASA Reveals That Our Solar System’s First Interstellar Visitor Is Shaped Like A Cigar

A newly discovered object from another star system that’s passing through ours is shaped like a giant cigar with a reddish hue, astronomers have revealed.

The asteroid, named ‘Oumuamua by its discoverers, is up to one-quarter mile (400 meters) long and highly-elongated – perhaps 10 times as long as it is wide.

That aspect ratio is greater than that of any asteroid or comet observed in our solar system to date.

While its elongated shape is quite surprising, and unlike asteroids seen in our solar system, it may provide new clues into how other solar systems formed.

The observations and analyses were funded in part by NASA and appear in the Nov. 20 issue of the journal Nature.




They suggest this unusual object had been wandering through the Milky Way, unattached to any star system, for hundreds of millions of years before its chance encounter with our star system.

For decades we’ve theorized that such interstellar objects are out there, and now, for the first time, we have direct evidence they exist,” said Thomas Zurbuchen, associate administrator for NASA’s Science Mission Directorate in Washington.

“This history-making discovery is opening a new window to study formation of solar systems beyond our own.”

Combining the images from the FORS instrument on the ESO telescope using four different filters with those of other large telescopes.

A team of astronomers led by Karen Meech of the Institute for Astronomy in Hawaii found that ‘Oumuamua varies in brightness by a factor of ten as it spins on its axis every 7.3 hours.

No known asteroid or comet from our solar system varies so widely in brightness, with such a large ratio between length and width.

The most elongated objects we have seen to date are no more than three times longer than they are wide.

This unusually big variation in brightness means that the object is highly elongated: about ten times as long as it is wide, with a complex, convoluted shape,” said Meech.

These properties suggest that ‘Oumuamua is dense, comprised of rock and possibly metals, has no water or ice, and that its surface was reddened due to the effects of irradiation from cosmic rays over hundreds of millions of years.

Scientists are certain this asteroid or comet originated outside our solar system.

First spotted last month by the Pan-STARRS telescope in Hawaii, it will stick around for another few years before departing our sun’s neighborhood.

Jewitt and his international team observed the object for five nights in late October using the Nordic Optical Telescope in the Canary Islands and the Kitt Peak National Observatory near Tucson, Arizona.

At approximately 100 feet by 100 feet by 600 feet, the object has proportions roughly similar to a fire extinguisher — though not nearly as red, Jewitt said.

The slightly red hue specifically pale pink and varying brightness are remarkably similar to asteroids in our own solar system, he noted.

In a paper to the Astrophysical Journal Letters, the scientists report that our solar system could be packed with 10,000 such interstellar travelers at any given time.

It takes 10 years to cross our solar system, providing plenty of future viewing opportunities, the scientists said.

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Pass it on: New Scientist

Mystery Of The Zombie Star That Won’t Die

A brightly burning ‘zombie‘ supernova that refuses to die has left astronomers baffled.

The star, which lies half a billion light years away, has exploded numerous times since 1954.

This has stumped astronomers as supernovas are generally considered to explode just once and standard theoretical models cannot explain its behaviour.

Researchers at Las Cumbres Observatory in Goleta, California, have been studying the phenomenon, which was first observed in 2014 by the Intermediate Palomar Transient Factory telescope near San Diego.

In January 2015 the event, known as iPTF14hls, was classified as a type II-P supernova, which results from the rapid collapse and violent explosion of a single massive star.




This type of supernova gives off a distinctive flash and tend to stay bright for around 100 days and supernovae lasting more than 130 days are extremely rare.

But iPTF14hls remained bright for almost two years (600 days), with the brightness of the light it emitted varying by up to 50 per cent over this time, as if it were exploding over and over again.

The evolution of the event also seems to be taking place roughly ten times slower than others of its type.

Adding to the puzzle, telescope imagery uncovered by the team suggests explosions may have taken place at the same location in 1954.

Supernovae are known to explode only once, shine for a few months and then fade, but iPTF14hls experienced at least two explosions, 60 years apart.

Writing in an opinion piece for the journal Nature, Stan Woosley, a professor of astronomy at the University of California, Santa Cruz, said of the findings.

As of now, no detailed model has been published that can explain the observed emission and constant temperature of iPTF14hls, let alone the possible eruption 60 years before the supernova.

“A better understanding could provide insight into the evolution of the most massive stars, the production of the brightest supernovae and possibly the birth of black holes that have masses near 40 solar masses, such as those associated with the first direct detection of gravitational waves.”

“For now, the supernova offers astronomers their greatest thrill: something they do not understand.”

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Oldest Monster Black Hole Ever Found Is 800 Million Times More Massive Than the Sun

Astronomers have discovered the oldest supermassive black hole ever found — a behemoth that grew to 800 million times the mass of the sun when the universe was just 5 percent of its current age, a new study finds.

This newfound giant black hole, which formed just 690 million years after the Big Bang, could one day help shed light on a number of cosmic mysteries.

Such as how black holes could have reached gargantuan sizes quickly after the Big Bang and how the universe got cleared of the murky fog that once filled the entire cosmos, the researchers said in the new study.




Supermassive black holes with masses millions to billions of times that of the sun are thought to lurk at the hearts of most, if not all, galaxies.

Previous research suggested these giants release extraordinarily large amounts of light when they rip apart stars and devour matter, and likely are the driving force behind quasars, which are among the brightest objects in the universe.

Astronomers can detect quasars from the farthest corners of the cosmos, making quasars among the most distant objects known.

The farthest quasars are also the earliest known quasars — the more distant one is, the more time its light took to reach Earth.

The previous record for the earliest, most distant quasar was set by ULAS J1120+0641. That quasar is located 13.04 billion light-years from Earth and existed about 750 million years after the Big Bang.

The newfound quasar (and its black hole), named ULAS J1342+0928, is 13.1 billion light-years away.

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Pass it on: Popular Science

Leftovers From The Moon’s Formation May Have Tunnelled To The Earth’s Core

The origin of our moon has long been debated.

Now, a scientist has claimed that Earth effectively ‘gave birth‘ to the moon four-and-a-half billion years ago.

A controversial new theory has been proposed that a giant explosion equivalent to 40 billion atomic bombs originating from the Earth’s core somehow led to the formation of the moon.

Planetary scientist Wim van Westrenen believes this violent event took place approximately four-and-a-half billion years ago and could answer the hotly contested question of where our moon comes from.

The scientist, from VU University in Amsterdam said that previous explanations about how the moon came to be simply do not add up.

Charles Darwin’s son, astronomer George Darwin, proposed that the early Earth spun so fast that it fell apart, hurling a part of itself into space that became the moon.





His theory was popular but was then eclipsed by the giant impact hypothesis, or ‘big splat‘, which said that a Mars-sized object crashed into an infant Earth and shattered on impact, the magazine reported.

In this theory, the debris formed the moon. However, it was largely thrown-out when astronauts brought back rocks from the Apollo moon landings.

Chemical analysis of the rocks last year by the University of Chicago found that they shared identical oxygen, silicon and potassium isotopes with Earth, hinting that the Moon shares its origin with the Earth.

Van Westeren said that taken at face value, the findings suggest that the moon was once part of the Earth that was blasted into space by an enormous explosion from the Earth’s fiery core.

To do this, he believes that there must have been a ‘massive energy kick‘ delivered quickly and he calculates that the explosion was the strength of 40 billion atomic bombs the size of those dropped on Hiroshima.

The idea that the Earth’s core harbours a huge nuclear reactor has been around for over 60 years.

There is also evidence of much smaller natural fossil reactors up to 10 metres across in West Africa that were active around 10 billion years ago.

This theory of  an internal nuclear reactor could explain why Earth gives out more energy than it receives from the sun.

However, experts have said that even if evidence of “global georeactors” was found, many scientists would need convincing that they were capable of creating the moon.

There are many conflicting ideas of exactly how the moon came to be and scientists are starting to re-question older theories.

Matija Cuk, a planetary scientist at Harvard University said: “I don’t think you can separate the moon’s formation from a giant impact.”

But he draws upon Darwin’s idea and the big splat and believes that a peculiar alignment of the sun, earth and moon is the reason why the moon orbits the Earth.

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Pass it on: New Scientist

Dwarf Galaxies Loom Large in Quest for Dark Matter

In its inaugural year of observations, the Dark Energy Survey has already turned up at least eight objects that look to be new satellite dwarf galaxies of the Milky Way.

These miniature galaxies — the first discovered in a decade — shine with a mere billionth of our galaxy’s brightness and each contain a million times less mass.

Astronomers believe the vast majority of material in dwarf galaxies is dark matter, a mysterious substance composing 80 percent of all matter in the universe.

Dwarf galaxies have therefore emerged as prime targets for gathering potential clues about dark matter’s composition.




Some theories suggest dark matter particles and antiparticles should produce telltale gamma rays when they collide with each other.

Accordingly, scientists used the Fermi Gamma-Ray Space Telescope to study the newfound dwarf galaxy candidates, as well as a group of dwarf galaxies already on the books.

The telescope detected no significant gamma-ray signals from either set of dwarf galaxies, however, leaving scientists still in the hunt for dark matter.

On May 15, 2015, The Kavli Foundation spoke with three astrophysicists about the continuing search for dark matter data in space and how dwarf galaxies can help us understand the evolution of our universe.

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Pass it on: New Scientist