Universe Today

August 29, 2013December 23, 2015 by Jason Major

Our Galaxy’s Supermassive Black Hole is a Sloppy Eater

X-ray and infrared image of Sgr A*, the supermassive black hole in the center of the Milky Way

Like most galaxies, our Milky Way has a dark monster in its middle: an enormous black hole with the mass of 4 million Suns inexorably dragging in anything that comes near. But even at this scale, a supermassive black hole like Sgr A* doesn’t actually consume everything that it gets its gravitational claws on — thanks to the Chandra X-ray Observatory, we now know that our SMB is a sloppy eater and most of the material it pulls in gets spit right back out into space.

(Perhaps it should be called the Cookie Monster in the middle.*)

New Chandra images of supermassive black hole Sagittarius A*, located about 26,000 light-years from Earth, indicate that less than 1% of the gas initially within its gravitational grasp ever reaches the event horizon. Instead, much of the gas is ejected before it gets near the event horizon and has a chance to brighten in x-ray emissions.

The new findings are the result of one of the longest campaigns ever performed with Chandra, with observations made over 5 weeks’ time in 2012.

“This new Chandra image is one of the coolest I’ve ever seen,” said study co-author Sera Markoff of the University of Amsterdam in the Netherlands. “We’re watching Sgr A* capture hot gas ejected by nearby stars, and funnel it in towards its event horizon.”

As it turns out, the wholesale ejection of gas is necessary for our resident supermassive black hole to capture any at all. It’s a physics trade-off.

“Most of the gas must be thrown out so that a small amount can reach the black hole”, said co-author Feng Yuan of Shanghai Astronomical Observatory in China. “Contrary to what some people think, black holes do not actually devour everything that’s pulled towards them. Sgr A* is apparently finding much of its food hard to swallow.”

If it seems odd that such a massive black hole would have problems slurping up gas, there are a couple of reasons for this.

One is pure Newtonian physics: to plunge over the event horizon, material captured — and subsequently accelerated — by a black hole must first lose heat and momentum. The ejection of the majority of matter allows this to occur.

The other is the nature of the environment in the black hole’s vicinity. The gas available to Sgr A* is very diffuse and super-hot, so it is hard for the black hole to capture and swallow it. Other more x-ray-bright black holes that power quasars and produce huge amounts of radiation have much cooler and denser gas reservoirs.

Illustration of gas cloud G2 approaching Sgr A* (ESO/MPE/M.Schartmann/J.Major)

Located relatively nearby, Sgr A* offers scientists an unprecedented view of the feeding behaviors of such an exotic astronomical object. Currently a gas cloud several times the mass of Earth, first spotted in 2011, is moving closer and closer to Sgr A* and is expected to be ripped apart and partially consumed in the coming weeks. Astronomers are eagerly awaiting the results.

“Sgr A* is one of very few black holes close enough for us to actually witness this process,” said Q. Daniel Wang of the University of Massachusetts at Amherst, who led the study.

Watch Black Holes: Monsters of the Cosmos

Source: Chandra press release. Read the team’s paper here.

Image credits: X-ray: NASA/UMass/D.Wang et al., IR: NASA/STScI

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*Any resemblance of Sgr A* to an actual Muppet, real or fictitious, is purely coincidental.

August 29, 2013December 23, 2015 by David Dickinson

Curiosity Spies a Martian Annular Eclipse

Phobos transiting the Sun as seen by the Mars Curiosity rover on Sol 369. (Credit: NASA/JPL-Caltech/Malin Space Science Systems/Texas A & M University).

It’s always interesting to consider the astronomical goings-on that occur under alien skies.

On August 17^th, Curiosity wowed us once again, catching the above sequence of images of the Martian moon Phobos transiting the Sun.

Such phenomena have been captured by the Curiosity, Opportunity and Spirit rovers before, as the twin Martian moons of Deimos & Phobos cross the face of the Sun. But these recent images taken by Curiosity’s right Mastcam pair are some of the sharpest yet.

Orbiting only an average of 6,000 kilometres above the surface of Mars, Phobos is the closest to its primary of any moon in the solar system. It appears about 11 arc minutes in size when directly overhead, about 3 times smaller than our own Moon does from the Earth.

“This event occurred near noon at Curiosity’s location, which put Phobos at its closest point to the rover, appearing larger against the Sun than it would at other times of the day,” Said co-investigator Mark Lemmon of Texas A&M University in a recent press release. “This is the closest to a total eclipse that you can have on Mars.”

Phobos is 40% more distant from an observer standing on the surface of Mars when it is rising above the local horizon than when it is overhead. The Sun is about 20’ arc minutes across as seen from Mars, 66% of its diameter as seen from the Earth.

The sequence above spans only six seconds in duration. You would easily note the apparent motion of Phobos as it drifted by! Also, since Phobos orbits Mars once every 7.7 hours, it actually rises in the west and sets in the east. The Martian day is over three times this span, at 24.6 hours long. Deimos has a more sedate orbit of 30.4 hours in duration.

The twin Moons of Deimos and Phobos were discovered this month back during the opposition of 1877 by Asaph Hall using the United States Naval Observatory’s newly installed 65 centimetre refractor. The moons are just within the grasp of eagle-eyed amateurs near opposition. You’ve got another opportunity to cross these elusive moons off of your life list coming up in the Spring of 2014.

image_preview — The telescope that was used to discover the moons of Mars. (Credit: The United States Naval Observatory).

It’s especially captivating that you can make out the irregular “potato shape” of Phobos in the above images. With low orbital inclinations relative to the equator of Mars of 1.1 degrees for Phobos and 0.9 degrees for Deimos, solar transits are not an uncommon occurrence, transpiring somewhere along the Martian surface with every orbit. If Phobos were twice as close to Mars, it would completely cover the Sun in a total solar eclipse. What Curiosity gave us this month is more akin to an annular eclipse with a ragged central shadow. An annular eclipse occurs when the occulting body is too distant to cover the Sun, leaving a bright, shining ring, or annulus.

On the Earth, we live in an epoch where annular eclipses are slightly more common than total solar eclipses, as the Moon currently recedes from us to the tune of 3.8 centimetres a year. About 1.4 billion years from now, the last total solar eclipse will be seen from the Earth. The next purely annular eclipse as seen from Earth occurs on April 29^th, 2014 across Australia and the Antarctic.

Conversely, Phobos is in a “death spiral,” meaning that it will one day crash into Mars about 30-50 million years from now. This also means that in about half that time, it will also be large enough to visually cover the Sun when crossing it near local noon. For a brief time far in the future, jagged total solar eclipses will be visible from Mars. That is, if the gravitational field of Mars doesn’t rip Phobos apart before that!

But beyond just aesthetics, these observations serve a scientific purpose as well. These phenomena serve to refine our understanding of the precise positions of Phobos and Deimos and their orbits.

“This one is by far the most detailed image of any Martian lunar transit ever taken, and it is especially useful because it is annular. It was taken closer to the Sun’s center than predicted, so we learned something.”

The track during the August 17^th observation was off by about 2-3 kilometres, allowing for a surprise central transit of the Sun as seen from Curiosity’s location.

Both Phobos and Deimos are captured asteroids only 22.2 & 12.6 kilometres across, respectively. Both must be subject to occasional bombardment from meteorites blasted off of the surface of nearby Mars. Sample return missions to Phobos have been proposed. Russia’s ill-fated Phobos-Grunt mission would’ve done just that.

Will humans ever stand on the surface of the Red Planet and witness an annular eclipse of the Sun by Phobos in person? Well, if we make it there by November 10^th, 2084, observers placed on the slopes of Elysium Mons will witness just such an event… with a rare transit of Earth and the Moon to boot!:

Arthur C. Clarke wrote of a transit of Earth from Mars that occurred in 1984 in his science fiction short story Transit of Earth.

Hey, I’m marking my calendar for the 2084 event… assuming, of course, my android body is ready by then!

August 29, 2013December 23, 2015 by Tammy Plotner

Trojan Asteroid Found Orbiting Uranus

One of three discovery images of 2011 QF99 taken from CFHT on 2011 October 24 (2011 QF99 is inside the green circle). This is the first of three images of the same patch of sky, taken one hour apart, that were then compared to find moving light-sources.

What’s new in the outer reaches of our solar system? Try the discovery of a Trojan asteroid orbiting Uranus. While a plethora of puns exist for this simple fact, the reality check is that this means there are far more of these objects out there than astronomers expected. The new Trojan even has a name – 2011 QF99!

A Trojan asteroid is a transient space rock which is temporarily captured by the gravity of a giant planet. It shares the planet’s orbital path, locked into a specific position known as a Lagrange point. What makes 2011 QF99 unusual is its presence in the outer solar system. Researchers found the scenario a bit unlikely. Why? The answer is simply because of planet size. According to theory, the strong gravitational pull of the larger neighboring planets should have destabilized any captured asteroid’s orbit and shot Uranian Trojans out of the neighborhood long ago.

So just how did this 60 kilometer-wide conglomeration of ice and rock end up circling Uranus? Astronomers turned towards computer modeling for the answer. The research team, including UBC astronomers Brett Gladman, Sarah Greenstreet and colleagues at the National Research Council of Canada and Observatoire de Besancon in France, did a simulation of the solar system and its co-orbital objects – including Trojan asteroids. A short-term animation showing the motion of 2011 QF99, as seen from above the north pole of the solar system can be found here.

“Surprisingly, our model predicts that at any given time three percent of scattered objects between Jupiter and Neptune should be co-orbitals of Uranus or Neptune,” says Mike Alexandersen, lead author of the study to be published tomorrow in the journal Science.

Until now, no one had made any estimates on the percentage of possible outer solar system Trojans. Unexpectedly, the amount ended up being far greater than earlier estimates. Just over the last 10 years, several temporary Trojans and co-orbitals have been cataloged and 2011 QF99 is one of them. It made its home around Uranus within the last few hundred thousand years and will eventually – in about a million years – escape Uranus’ gravity.

“This tells us something about the current evolution of the solar system,” says Alexandersen. “By studying the process by which Trojans become temporarily captured, one can better understand how objects migrate into the planetary region of the solar system.”

Original Story Source: UBC News Release.

August 29, 2013December 30, 2015 by Jason Major

Black Holes: Monsters of the Cosmos

It’s a new Symphony of Science video from melodysheep (aka John D. Boswell). It features Neil deGrasse Tyson, Lawrence Krauss, Michio Kaku, and Morgan Freeman. It’s about black holes.

‘Nuff said. Enjoy!

August 29, 2013December 23, 2015 by Nancy Atkinson

Iran Releases Plans for Manned Spacecraft

An graphic released of an Iranian space capsule capable of carrying humans to space. Via ISNA.

After Iran launched a monkey in a suborbital rocket earlier this year, they are now setting their sights on sending humans to orbit, according to the Iranian news agency ISNA. The news release says researchers at the University of Haj Nasir “have designed and built a manned spacecraft,” but only images of basic designs were released.

The spacecraft appears to be a classic capsule design, and is capable of carrying “one to three people to lower orbits for several hours. This type of aircraft is made up of several modules.”

The researchers, Leila Khalajzadeh and Mehran Shams, were reported as saying in their presentation that the capsule design is the most economical type of spacecraft.

The Israeli news site Hayadan reports that Tal Inbar, head of the Space and UAV Research Center at Fisher Institute for Air and Space Strategic Studies in Israel, says that no technical data was released from Iran on the new spacecraft designs, nor have they provided information about the launch vehicle required to send the capsule to space.

According to details released earlier by the Iranian space agency, they want to launch the first sub-orbital spaceflight with an Iranian on board by 2016 at an altitude below 200 kilometers as preparation for the eventual orbital spaceflight.

Iranian participation in the future Chinese space station program has also been discussed.

Reportedly, much of Iran’s technological equipment derives from modified Chinese and North Korean technology. In 2008, Iran successfully launched a two-stage all solid-fuel sub-orbital sounding rocket called the Kavoshgar-1 (Explorer-1), for the first sub-orbital test flight from the Shahroud space launch complex. Later, in 2010-2013, at least three animal flight tests were sent on suborbital launches, some flights with outright failures, others with varying degrees of success.

Sources: ISNA, Hayadan

August 29, 2013December 23, 2015 by Elizabeth Howell

Two Astronauts Who Beat The Odds To Get Into Space

In white suits: JAXA astronaut Koichi Wakata (left) and NASA astronaut Rick Mastracchio during spacewalk training for Expeditions 38/39. Credit: NASA

Getting into space is never a guarantee for an astronaut. Heck, getting into an astronaut program can be tough, as Koichi Wakata and Rick Mastracchio told Universe Today.

The crewmates on Expedition 38/39 are supposed to head to the International Space Station in November. But they beat incredible odds to be selected in the first place. Wakata, who is with the Japanese Aerospace Exploration Agency (JAXA), didn’t even have an astronaut program to join when he was a kid. Mastracchio (from NASA) did, but it took him nine years’ worth of applications to get in.

“When I was five years old, I saw the Apollo [11] lunar landing,” Wakata said. “This was before I was going to school, kindergarten timeframe. But there was no astronaut program in Japan, so I thought it was physically beyond my reach. It was something I longed for.”

With no Japanese astronauts to look up to, Wakata put himself in a related career: airplane engineering. Between 1989 and 1992, he worked as an aircraft structural engineer for Japan Airlines. It was while he was in this career that he saw a newspaper advertisement recruiting the first Japanese astronauts. He applied and was let in, first try.

JAXA astronaut Koichi Wakata takes photos of Earth during Expedition 19/20 in 2009. Credit: NASA

“I was lucky to get into this program,” Wakata said. And now he has a new milestone in his sights: becoming the first Japanese commander of the International Space Station during Expedition 39. Wakata’s space experience includes operating every piece of robotics hardware currently on orbit, from the Canadarm to the Japanese Kibo robotic arm.

He also has extensive leadership training behind him, which helped him prepare for command. He was in charge of an underwater lab (called NASA Extreme Environment Mission Operations, or NEEMO) in 2006. Wakata also received National Outdoor Leadership training, which puts people in wilderness situations to test their skills.

Finally, Wakata also watched closely what his own spaceflight commanders did. He is a big admirer of Brian Duffy, who flew four times in space — including two of Wakata’s missions. “I learned a lot from him and I try to imitate what he did,” Wakata said.

Unlike Wakata, his crewmate Mastracchio was born in a country with a well-established astronaut program. That also meant, however, a lot of competition. Mastracchio made applications practically every year between 1987 and 1996. Every time he was turned down, he would look for a way to make himself better for the next round.

Rick Mastracchio takes a selfie during a spacewalk on STS-118. NASA's web page says the purpose was to have a photo of his helmet visor. Credit: NASA — Rick Mastracchio takes a selfie during a spacewalk on STS-118. NASA’s web page says the purpose was to have a photo of his helmet visor. Credit: NASA

“I tried not to do things to become an astronaut. I tried to do things that I thought would be interesting,” Mastracchio said. At the same time, those interesting things happened to be items that astronauts would find useful.

Hired in 1987 for Rockwell Shuttle Operations Company in Houston, Mastracchio then moved to NASA in 1990 as an engineer in the flight crew operations directorate. He earned a masters degree in physical science at the nearby University of Houston-Clear Lake in 1991. Mastracchio also got a pilot’s license.

Around the same time of another unsuccessful selection in 1994, Mastracchio switched jobs and became a flight controller in the front room of Mission Control. It’s hard to say if that made the difference, he acknowledged, but for what it’s worth he was selected in 1996. “I just gained more experience, over time, in different jobs,” he said.

Mastracchio has since flown three times into space, performing six spacewalks in that time. There are no further “outside” activities planned for him during Expedition 38/39, but he has trained as a backup just in case.

August 28, 2013December 23, 2015 by Nancy Atkinson

NASA Crashes a Helicopter With 15 Dummies Inside on Purpose: Watch the Video

Crash test dummy mayhem after the NASA helicopter crash test on August 28, 2013. Credit: NASA/Langley Research Center.

Not only did NASA purposely crash a Marine helicopter today, but they also stuffed 15 crash test dummies inside for a group “crash” party and filmed the event from every angle imaginable. The crash test took place at the Langley Research Center in Hampton, Virginia and engineers dropped an old Marine CH-46E helicopter fuselage from a height of about 9 meters (30 feet), traveling at about 48 km/h (30 mph) to test improved seats and seatbelts and gather data on the odds of surviving a helicopter crash.

“We designed this test to simulate a severe but survivable crash under both civilian and military requirements,” said NASA lead test engineer Martin Annett. “It was amazingly complicated with all the dummies, cameras, instrumentation and the collaborators, but it went well.”

The fuselage hit hard, as evidenced by the video and images NASA has released. Thirteen instrumented crash-test dummies and two un-instrumented manikins had a rough ride, as did some of the 40 cameras mounted inside and outside the fuselage. Preliminary observations indicate good data collection, which will take months to analyze.

The CH-46E helicopter fuselage ready for its crash test. Credit: NASA/Langely Research Center.

Researchers used the cameras as well as onboard computers, which data from 350 instrumentation points, to record every move of the 10,300-pound aircraft and its contents. The helicopter’s unusual black-and-white-speckled paint job — a photographic technique called full field photogrammetry — also aided in the data collection effort.

“High speed cameras filming at 500 images per second tracked each black dot, so after everything is over, we can plot exactly how the fuselage reacted structurally throughout the test,” said NASA test engineer Justin Littell.

NASA will use the results of both tests in efforts to improve helicopter performance, efficiency and safety. Researchers also want to increase industry knowledge and create more complete computer models that can be used to design better and safer helicopters.

You can see more images and video at the Langely Research Center’s Flickr page.

August 28, 2013December 23, 2015 by Nancy Atkinson

Astrophoto: Can You Count the 292 Pink Nebulae in the Triangulum Galaxy?

M33, the Triangulum Spiral Galaxy, seen here in a 4.3 hour exposure image. Astronomers used JWST to examine a section of its south spiral arm to search out and find nearly 800 newly forming stars. Credit and copyright: John Chumack.

Take a look at this stunning new close-up of M33, the Triangulum Galaxy by one of our favorite astrophotographers, John Chumack. “The thing that amazes me about M33 other than it being our neighbor and a beautiful spiral galaxy, is that M33 is loaded with 292 pink nebulae (HII Star Formation Regions),” John said via email, “the largest pink nebula being NGC-604, which is actually visible in a 6″ diameter telescope…to be able to see nebula visually in other galaxies — now that is really cool!”

Your challenge for the day: how many nebulae can you count in this beautiful new image? There are also star clusters and even a few globular clusters in the image, as well.

M33 is about 2.6 million light years away and is the second closest spiral galaxy to us, next to the Andromeda galaxy. “Due to its very low surface brightness it can be a challenge to see from or nearby cities,” John explained, “but from a dark location on a perfectly clear night and assuming you have 20/20 vision, it is the furthest object the Human eye could see into deep space without optical aid.”

John used a QHY8 CCD + 16″ reflector in this 4.3 hour exposure. Pretty in pink!

John Chumack's daughter Kayla took this picture of her Dad holding a 16x24 print of M33. Image courtesy of John Chumack. — John Chumack’s daughter Kayla took this picture of her Dad holding a 16×24 print of M33. Image courtesy of John Chumack.

John said he always runs his images by his wife and children to get their final okay, if it looks good to them, then he knows it’s a keeper! His daughter Kayla liked this one enough to want to take a picture of her Dad holding a print of it.

See more of John’s work at his website, Galactic Images, or on his Flickr page.

Want to get your astrophoto featured on Universe Today? Join our Flickr group or send us your images by email (this means you’re giving us permission to post them). Please explain what’s in the picture, when you took it, the equipment you used, etc.

August 28, 2013December 23, 2015 by Elizabeth Howell

Russian Meteor Experienced Melting Before Slamming Into Earth: Study

The two main smoke trails left by the Russian meteorite as it passed over the city of Chelyabinsk. Credit: AP Photo/Chelyabinsk.ru

A collision or “near miss” caused melting in the Chelyabinsk meteor before it slammed into Earth’s atmosphere this February, causing damage and injuries to hundreds in the remote Russian region.

A new study, presented at the Goldschmidt Conference in Florence, Italy, says some meteorite fragments’ composition shows strong evidence of heating, which is an indication of interplanetary violence of some sort.

“The meteorite which landed near Chelyabinsk is a type known as an LL5 chondrite, and it’s fairly common for these to have undergone a melting process before they fall to Earth,” stated Victor Sharygin, a researcher from the Sobolev Institute of Geology and Mineralogy in Russia.

“This almost certainly means that there was a collision between the Chelyabinsk meteorite and another body in the solar system, or a near miss with the Sun.”

Chelyabinsk’s size of 59 feet (18 meters) was by no means a very large meteor, but it was enough to cause car alarms to go off and to shatter glass when it exploded over Russia on Feb. 15. Its arrival brought the danger of space rocks once again to public attention.

In just the few short months since its arrival, a number of research studies have begun to sketch out its origins and effects. One recent NASA study showed that the cloud of dust from the explosion spread around the northern hemisphere in days.

Model and satellite data show that four days after the bolide explosion, the faster, higher portion of the plume (red) had snaked its way entirely around the northern hemisphere and back to Chelyabinsk, Russia. Image Credit: NASA's Goddard Space Flight Center Scientific Visualization — Model and satellite data show that four days after the bolide explosion, the faster, higher portion of the plume (red) had snaked its way entirely around the northern hemisphere and back to Chelyabinsk, Russia.
Image Credit: NASA’s Goddard Space Flight Center Scientific Visualization

Sharygin’s team analyzed several fragments of the meteorites and put them into three groups: light, dark and intermediate. Lights ones were the most abundant. Dark fragments were most commonly found in the area where the meteorite hit the Earth.

While only three of the dark fragments show there was previous melting, the researchers say it’s quite possible that more samples might be available from the public and most notably, from the main portion that is still at the bottom of Chebarkul Lake.

“The dark fragments include a large proportion of fine-grained material, and their structure, texture and mineral composition shows they were formed by a very intensive melting process,” a press release stated.

“This material is distinct from the ‘fusion crust’ – the thin layer of material on the surface of the meteorite that melts, then solidifies, as it travels through the Earth’s atmosphere.”

A "fusion crust" or melting is visible in this fragment of the Chelyabinsk meteorite. Credit: Victor Sharygin — A “fusion crust” or melting is visible in this fragment of the Chelyabinsk meteorite. Credit: Victor Sharygin

Researchers also spotted “bubbles” in the dark fragments that they consider either “perfect crystals” of oxides, silicates and metal or little spots that are filled up with sulfide or metal.

They also saw platinum-type elements in the crust, which was a surprise as the time it takes for a crust to fuse is too short for platinum to form.

“We think the appearance (formation) of this platinum group mineral in the fusion crust may be linked to compositional changes in metal-sulfide liquid during remelting and oxidation processes as the meteorite came into contact with atmospheric oxygen,” Sharygin stated.

The work is ongoing, and no submission date for a study for publication was disclosed.

Source: EurekAlert!

August 28, 2013December 23, 2015 by Elizabeth Howell

Double Vision: Scientists Spot An Elder ‘Twin’ To the Sun

The life-cycle of a Sun-like star from protostar (left side) to red giant (near the right side) to white dwarf (far right). Credit: ESO/M. Kornmesser

If you want a picture of how you’ll look in 30 years, youngsters are told, look at your parents. The same principle is true of astronomy, where scientists compare similar stars in different age groups to see how they progress.

We have a special interest in learning how the Sun will look in a few billion years because, you know, it’s the main source of energy and life on Earth. Newly discovered HIP 102152 could give us some clues. The star is four billion years older than the sun, but so close in composition that researchers consider it almost like a twin.

Telescopes have only been around for a few centuries, making it hard to project what happens during the billions upon billions of years for a star’s lifetime. We have about 400 years of observations on the sun, for example, which is a minute fraction of its 4.6 billion-year-old lifespan so far.

The Sun in H-Alpha, on 01-07-2013, using a Lunt Solar LS60Scope/LS50 Hydrogen Alpha Solar filter. Credit: John Chumack — Today, we take telescopic observations of the Sun for granted, but the technology only became available about 400 years ago. This picture shows the Sun in H-Alpha, on 01-07-2013, using a Lunt Solar LS60Scope/LS50 Hydrogen Alpha Solar filter. Credit: John Chumack

“It is very hard to study the history and future evolution of our star, but we can do this by hunting for rare stars that are almost exactly like our own, but at different stages of their lives,” stated the European Southern Observatory.

ESO’s Very Large Telescope — guided by a team led by the University of Sao Paulo’s Jorge Melendez — examined HIP 102152 with a spectrograph that broke up the light into various colors, revealing properties such as chemical composition. Around the same time, they scrutinized 18 Scorpii, also considered to be a twin but one that is younger than the sun (2.9 billion years old)

So what can we predict about the Sun’s future? One thing puzzling scientists has been the amount of lithium in our closest stellar companion. Although the Big Bang (the beginning of the universe) created hydrogen, helium and lithium, only the first two elements are abundant in the Sun.

HIP 102152, it turns out, also has low levels of lithium. Why isn’t clear yet, ESO notes, although “several processes have been proposed to transport lithium from the surface of a star into its deeper layers, where it is then destroyed.” Previous observations of young Sun-like stars also show higher levels of lithium, implying something changes between youth and middle age.

The elder twin to our Sun may host another discovery: there could be Earth-sized planets circling the star. Chemical properties of HIP 102152 show that it has few elements that you see in meteorites and rocky planets, implying the elements are “locked up” in bodies close to the star. “This is a strong hint that HIP 102152 may host terrestrial rocky planets,” ESO stated.

Better yet, separate observations showed that there are no giant planets close to the star — leaving room for Earth-sized planets to flourish.

The research is available in a recent edition of Astrophysical Letters.

Source: European Southern Observatory