Tag: bright (page 2 of 11)

NASA wants your vote on Ceres’ mysterious bright spots

April 28, 2015 / / 0 Comments

NASA wants your vote on Ceres’ bright spots

The nature of the bright spots has yet to be elucidated.




Excerpt from thespacereporter.com

NASA’s Jet Propulsion Laboratory has set up a website at which members of the public can register their votes as to the identify of the strange and unexpected bright spots seen on Ceres by the Dawn probe. Although Dawn will study the spots in much greater detail in the near future, having just assumed its first scientific orbit, in the meantime the nature of spots in anyone’s guess. This author voted for “ice”.

It seems ice is the most popular possibility so far, with 33 percent of the vote. The next most popular choice is “other”, with 28 percent. “Volcano” and “geyser” both have 11 percent, “salt deposit” has nine percent, and “rock” has eight percent.

At about 590 miles in diameter, Ceres is the largest body in the asteroid belt between the orbits of Mars and Jupiter. Dawn had imaged Ceres’s surface throughout its approach. Dawn entered orbit of Ceres on March 6, the first spacecraft to orbit a dwarf planet. From 2011 to 2012, Dawn also orbited the asteroid Vesta, the second-most massive body in the asteroid belt. Having studied both Vesta and Ceres, Dawn is the first spacecraft in history to orbit two extraterrestrial objects. Dawn’s investigations of Vesta and Ceres will shed light on the early evolution of our solar system; both bodies represent incipient planets, gravitationally perturbed early in their formation.

“The approach imaging campaign has completed successfully by giving us a preliminary, tantalizing view of the world Dawn is about to start exploring in detail. It has allowed us to start asking some new and intriguing questions,” said Marc Rayman, Dawn’s mission director and chief engineer at the JPL, in a separate NASA statement.

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New research shows Universe expansion pace isn’t as fast as assumed earlier

April 11, 2015 / / 0 Comments



universe


Excerpt from thewestsidestory.net

The Universe is expanding and any student of astronomy will vouch to this fact. However according to a team of astronomers the acceleration of the universe may not be as quick as it was assumed earlier.

A team of astronomers have discovered that certain types of supernova are more varied than earlier thought of and in the process have led to the biggest mystery of the universe-how fast is the universe expanding after the big bang?

Peter A. Milne of the University of Arizona said, “We found that the differences are not random, but lead to separating Ia supernovae into two groups, where the group that is in the minority near us are in the majority at large distances — and thus when the universe was younger, there are different populations out there, and they have not been recognized. The big assumption has been that as you go from near to far, type Ia supernovae are the same. That doesn’t appear to be the case.”
The discovery throws new light on the currently accepted view of the universe expanding at a faster and faster rate pulled apart by an unknown force called dark energy this observation resulted in 2011 Nobel Prize for Physics.
Milne said, “The idea behind this reasoning, is that type Ia supernovae happen to be the same brightness — they all end up pretty similar when they explode. Once people knew why, they started using them as mileposts for the far side of the universe.The faraway supernovae should be like the ones nearby because they look like them, but because they’re fainter than expected, it led people to conclude they’re farther away than expected, and this in turn has led to the conclusion that the universe is expanding faster than it did in the past.”
The researchers felt that the accelerating universe can be explained on the basis of color difference in between two groups of supernova leaving less acceleration than earlier assumed and in the process will require lesser dark energy.

Milne said, “We’re proposing that our data suggest there might be less dark energy than textbook knowledge, but we can’t put a number on it, until our paper, the two populations of supernovae were treated as the same population. To get that final answer, you need to do all that work again, separately for the red and for the blue population.

Type la supernovae are considered as a benchmark for far away sources of light they do have a fraction of variability which has limited our knowledge of the size of the universe.
The distance of objects with the aid of our binocular vision and the best space-based telescopes and most sophisticated techniques works out in the range of ten or twenty thousand light years. 
However as compared to the vastness of space, this is just pea nuts.
For Distances greater than that it is imperative to compare the absolute and observed brightness of well understood objects and to use the difference to determine the object’s distance.

In astronomy it is difficult to find an object of known brightness since there are examples of both bright and dim stars and galaxies. However there is one event which can be used to work out its absolute brightness. Supernovas are the final stages of a dying star and it explodes with such violence, the flash can be seen across the vast universe.

Type la Supernovae occurs in a binary star system when a white dwarf scoops off mass from its fellow star. This reproducible mechanism gives a well determined brightness and therefore scientists term such Type la supernovae as ‘standard candles’.

Astronomers found that the Type la supernovae is so uniform that it has been designated as cosmic beacons and used to assess the depths of the universe. It is now revealed that they fall into different populations and are not very uniform as previously thought. .

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Huge Alien Planet Bathes in the Light of Four Suns

April 5, 2015 / / 0 Comments



30 Ari with its newly discovered companion stars
Karen Teramura

Excerpt from nbcnews.com


Astronomers have spotted a fourth star in a planetary system called 30 Ari, bringing the number of known planet-harboring quadruple-sun systems to two. 

"Star systems come in myriad forms. There can be single stars, binary stars, triple stars, even quintuple star systems," study lead author Lewis Roberts, of NASA's Jet Propulsion Laboratory, said in a statement. "It's amazing the way nature puts these things together." 

30 Ari lies 136 light-years from the sun in the constellation Aries. Astronomers discovered a giant planet in the system in 2009; the world is about 10 times more massive than Jupiter and orbits its primary star every 335 days. There's also a pair of stars that lie approximately 1,670 astronomical units away. (One AU is the distance between Earth and the sun — about 93 million miles, or 150 million kilometers).

The newfound star circles its companion once every 80 years, at a distance of just 22 AU, but it does not appear to affect the exoplanet's orbit despite such proximity. This is a surprising result that will require further observations to understand, researchers said. 

To a hypothetical observer cruising through the giant planet's atmosphere, the sky would appear to host one small sun and two bright stars visible in daylight. With a large enough telescope, one of the bright stars could be resolved into a binary pair. 

The discovery marks just the second time a planet has been identified in a four-star system. The first four-star planet, PH1b or Kepler-64b, was spotted in 2012 by citizen scientists using publicly available data from NASA's Kepler mission. 

Planets with multiple suns have become less of a novelty in recent years, as astronomers have found a number of real worlds that resemble Tatooine, Luke Skywalker's home planet in the Star Wars films. 

The research was published online this month in the Astronomical Journal.

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Citizen Scientists Find Green Blobs in Hubble Galaxy Shots

April 3, 2015 / / 0 Comments





Excerpt from wired.com

In 2007, A Dutch schoolteacher named Hanny var Arkel discovered a weird green glob of gas in space. Sifting through pictures of galaxies online, as part of the citizen science project Galaxy Zoo, she saw a cloud, seemingly glowing, sitting next to a galaxy. Intrigued, astronomers set out to find more of these objects, dubbed Hanny’s Voorwerp (“Hanny’s object” in Dutch). Now, again with the help of citizen scientists, they’ve found 19 more of them, using the Hubble space telescope to snap the eight haunting pictures in the gallery above.



Since var Arkel found the first of these objects, hundreds more volunteers have swarmed to help identify parts of the universe in the Galaxy Zoo gallery. To find this new set, a couple hundred volunteers went through nearly 16,000 pictures online (seven people went through all of them), clicking yes/no/maybe as to whether they saw a weird green blob. Astronomers followed up on the galaxies they identified using ground-based telescopes, and confirmed 19 new galaxies surrounded by green gas.



What causes these wispy tendrils of gas to glow? Lurking at the center of each of these galaxies is a supermassive black hole, millions to billions times as massive as the sun, with gravity so strong that even light can’t escape them. As nearby gas and dust swirls into the black hole, like water circling a drain, that material heats up, producing lots of radiation—including powerful ultraviolet. Beaming out from the galaxy, that ultraviolet radiation strikes nearby clouds of gas, left over from past collisions between galaxies. And it makes the clouds glow an eerie green. “A lot of these bizarre forms we’re seeing in the images arise because these galaxies either interacted with a companion or show evidence they merged with a smaller galaxy,” says William Keel, an astronomer at the University of Alabama, Tuscaloosa.



The eight in this gallery, captured with Hubble, are especially weird. That’s because the quasar, the black-hole engine that’s supposed to be churning out the ultraviolet radiation, is dim—too dim, in fact, to be illuminating the green gas. Apparently, the once-bright quasar has faded. But because that UV light takes hundreds of thousands of years to travel, it can continue to illuminate the gas long after its light source has died away.  


Hubble finds phantom objects close to dead quasars

That glowing gas can tell astronomers a lot about the quasar that brought it to light. “What I’m so excited about is the fact that we can use them to do archaeology,” says Gabriela Canalizo, an astronomer at the University of California, Riverside, who wasn’t part of the new research. Because the streaks of gas are so vast, stretching up to tens of thousands of light years, the way they glow reveals the history of the radiation coming from the quasar. As the quasar fades, so will the gas’s glow, with the regions of gas closer to the quasar dimming first. By analyzing how the glow dwindles with distance from the quasar, astronomers can determine how fast the quasar is fading. “This was something we’ve never been able to do,” Canalizo says.

Measuring how fast the quasar fades allows astronomers to figure out exactly what’s causing it to turn off in the first place. “What makes them dim is running out of material to eat,” Canalizo says. That could happen if the quasar is generating enough radiation to blow away all the gas and dust surrounding the black hole—the same gas and dust that feeds it. Without a steady diet, the quasar is powerless to produce radiation. Only if more gas happens to make its way toward the black hole can the quasar turn on again. The glowing gas can provide details of this process, and if other mechanisms are at play.

With more powerful telescopes, astronomers will likely find many more. Hanny’s Verwoort, it turns out, may not be that weird after all.

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UFO Crash in Canada? No says military Canadian Forces

March 25, 2015 / / 0 Comments

 Posts like these were circulating on Twitter and Facebook on Wednesday night, with people suggesting there was a UFO crash near Jackhead, Man. It was actually an airplane being used in a military training exercise, according to the Canadian Forces.



Excerpt from cbc.ca

Social media reports of a possible UFO sighting last night near Jackhead, Man., are not true, says the Canadian Forces, which attributed the bright light people saw to an airplane from a training exercise.

On Wednesday night (Feb 18th, 2015), several people said on Twitter and Facebook that they saw a bright light in the sky, fuelling speculation that it may have been an unidentified flying object.

The rumour became stronger when photos were posted of Canadian Forces vehicles in the area, with some people claiming the military was there to contain a UFO crash site.

But it was not a UFO at all, says Lt.-Col. Paul Davies, commanding officer 38 Territorial Battalion Group, which is involved in an Arctic Response Company Group training exercise on Lake Winnipeg this week.

Exercise Arctic Bison 2015
Members of the Arctic Response Company Group drive across frozen Lake Winnipeg during Exercise Arctic Bison 2015. (MCpl Cameron Skrypnyk/DND)


"There's no aliens, just my friends in the air force who are out there helping us on this exercise," Davies told CBC News on Thursday.
"I have the commander of that air force contingent sitting right beside me and, you know, he assures us that that was not a UFO, but that was him."

About 150 military personnel are taking part in Exercise Arctic Bison 2015, which includes the 38 Canadian Brigade Group, the 2nd Battalion of the Princess Patricia’s Canadian Light Infantry, the 4th Canadian Ranger Patrol Group, and 440 Squadron of the Royal Canadian Air Force.

Davies said soldiers are training to deal with a plane crash and provide ground search and rescue support in the Arctic.

The bright light that people saw, he explained, came from an airplane that takes off very quickly.

"From a distance it may have looked like it was going straight up in the air, but it wasn't," he said. "It was just us out there playing our games."

The exercise wraps up on Sunday.

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Amazing Images of Comet 67P/Churyumov-Gerasimenko

March 21, 2015 / / 0 Comments

Rosetta photo of Comet 67P/C-G.
Comet 67P/C-G is about as large as Central Park of Manhattan Island, New York

Excerpt from nytimes.com

By JONATHAN CORUM 


The European Space Agency’s Rosetta spacecraft caught up with Comet 67P/Churyumov-Gerasimenko last August, then dropped a lander onto the comet in November. Now Rosetta will follow the rubber-duck-shaped comet as it swings closer to the sun.
Scale in miles
Scale in km
Rosetta photo of Comet 67P/C-G.
1/2 MILE

March 9 Rosetta was 45 miles from Comet 67P/C-G when it photographed the comet’s head ringed with a halo of gas and dust. These jets extend from active areas of the comet’s surface and will become much more prominent over the next few months as the comet approaches the sun.
Rosetta photo of Comet 67P/C-G.
1/2 MILE

March 6 The comet’s head is angled down in this image of crisscrossing sunlit jets taken from 53 miles away.
Comet’s location when Rosetta was launched Rosetta launched in March 2004
Earth
Sun
Mars
Rendezvous
with Comet
67P/C-G
Orbit of
Jupiter
Rosetta today

Where is Rosetta? The Rosetta spacecraft took 10 years to match speed and direction with Comet 67P/C-G. The chase ended last August, and Rosetta will now follow the comet in its elliptical orbit as it moves closer to the sun. The spacecraft is no longer orbiting the comet because of increasing dust, but it is planning a series of close flybys.
Rosetta photo of Comet 67P/C-G.
1/2 MILE

March 6 Rosetta was 52 miles away when it looked up at the comet’s flat underbelly. The smooth plain at center covered with large boulders is named Imhotep.
Rosetta photo of Comet 67P/C-G.
1/2 MILE

Feb. 28 Rosetta captured a profile of the comet surrounded by curving jets of gas and dust from active regions. The spacecraft was 64 miles away.
Rosetta photo of Comet 67P/C-G.

Feb. 25–27 One day on Comet 67P/C-G is about 12 hours, the time it takes the comet to spin on its axis. The jets of gas and dust surrounding the comet are thought to curve from a combination of the comet’s rotation and the uneven gravity of its two-lobed structure.
Rosetta photo of Comet 67P/C-G.
1/2 MILE

Feb. 20 The comet’s sunlit underbelly casts a shadow obscuring the neck that joins the two lobes. Rosetta took this image from 74 miles away.
Rosetta photo of Comet 67P/C-G.
1 MILE

Feb. 18 Pale jets of gas and dust surround Comet 67P/C-G, seen from 123 miles away. Bright marks in the background are a mix of stars, camera noise and streaks from small particles ejected from the comet.
Rosetta photo of Comet 67P/C-G.
1/4 MILE
Panorama by The New York Times

Feb. 14 On Valentine’s Day, Rosetta made its first close flyby of the comet, passing within four miles of the surface. Here the spacecraft looks down on the large depression at the top of the comet’s head.
Rosetta photo of Comet 67P/C-G.
500 FEET

Feb. 14 An image of the comet’s underbelly taken six miles above the surface during the Valentine’s Day flyby. The smooth plain in the foreground is called Imhotep.
Rosetta photo of Comet 67P/C-G.
1/2 MILE

Feb. 9 The comet is upside down in this image from 65 miles away, and a fan-shaped jet of dust streams from the comet’s neck region.
Rosetta photo of Comet 67P/C-G.
1/2 MILE

Feb. 6 Jets of gas and dust extend from the comet’s neck and other sunlit areas in this image taken from 77 miles away.
Rosetta photo of Comet 67P/C-G.
1/4 MILE

Feb. 3 This close-up image of the comet’s neck was taken from 18 miles away, and was the last image taken from orbit around Comet 67P/C-G. Rosetta will continue to follow the comet, but will leave its gravity-bound orbit because of increasing dust and instead begin a series of flybys.
Rosetta photo of Comet 67P/C-G.
1/4 MILE

Jan. 31 The comet’s head, neck and back are sunlit in this image taken from 17 miles away. A prominent jet of gas and dust extends from an active region of the surface near the comet’s neck.
Rosetta photo of Comet 67P/C-G.
1/4 MILE

Jan. 16 The tail of the comet’s larger lobe points up, revealing a smooth plain named Imhotep at left. Rosetta was 18 miles away when it took this image.
Rosetta photo of Comet 67P/C-G.
1/4 MILE

Jan. 3 The smooth plain named Imhotep, at center right, lies on the comet’s flat underbelly, seen here from a distance of about 18 miles.
Rosetta photo of Comet 67P/C-G.
1/4 MILE
Cheops
IMHOTEP

Dec. 14, 2014 The large triangular boulder on the flat Imhotep plain is named Cheops, after the Egyptian pyramid. The spacecraft was about 12 miles from the comet when it took this image.
Rosetta photo of Comet 67P/C-G.
1/4 MILE

Dec. 10 Sunlight falls between the body and head of the comet, lighting up a large group of boulders in the smooth Hapi region of the comet’s neck. To the right of the boulders, the cliffs of Hathor form the underside of the comet’s head. Rosetta took this image from a distance of 12 miles.
Rosetta photo of Comet 67P/C-G.
1/4 MILE

Dec. 2 The round depression in the middle of the comet’s head is filled with shadow in this image taken 12 miles above the comet.
Rosetta photo of Comet 67P/C-G.
1/4 MILE

Nov. 22 An overexposed image of Comet 67P/C-G from 19 miles away shows faint jets of gas and dust extending from the sunlit side of the comet.
Philae photo from the surface of Comet 67P/C-G.

Nov. 12 Rosetta’s washing-machine sized lander Philae successfully touched down on the comet’s head. But anchoring harpoons failed and Philae bounced twice before going missing in the shadow of a cliff or crater (above). Without sunlight Philae quickly lost power, but might revive as the comet gets closer to the sun. On March 12, Rosetta resumed listening for radio signals from the missing lander.
Rosetta photo of Comet 67P/C-G.

Photo illustration by The New York Times

How big is the comet? The body of Comet 67P/C-G is about as long as Central Park. For images of Rosetta’s rendezvous and the Philae landing, see Landing on a Comet, 317 Million Miles From Home.

Sources: European Space Agency and the Rosetta mission. Images by ESA/Rosetta, except where noted. Some images are composite panoramas created by ESA, and most images were processed by ESA to bring out details of the comet’s activity.

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MAVEN mission finds early surprises in Martian atmosphere

March 20, 2015 / / 0 Comments

Excerpt from chroniclebulletin.com University of Colorado-led Mars mission has observed two unexpected phenomena in the Martian atmosphere, unveiled Wednesday at the 46th Lunar and Planetary Science Conference in Texas.NASA describes the finds by MA...

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Warp in spacetime lets astronomers watch the same star explode four times

March 8, 2015 / / 0 Comments



Excerpt from csmonitor.com

Thanks to a phenomenon known as gravitational lensing, the Hubble Space Telescope has captured four images of the same supernova explosion.

For the first time, a cosmic magnifying glass has allowed scientists to see the same star explosion four times, possibly offering a revealing glimpse into these explosive stellar deaths and the nature of the accelerating universe.

Astronomers using the Hubble Space Telescope have captured four images of a supernova explosion in deep space thanks to a galaxy located between Earth and the massive star explosion. You can see how Hubble saw the supernova in this NASA video. The galaxy cluster warped the fabric of space and time around it — like a bowling ball placed on a bed sheet — allowing scientists to see the supernova in four images.

"It was predicted 50 years ago that a supernova could be gravitationally lensed like this, but it's taken a long time for someone to find an example," lead study author Patrick Kelly, an astronomer at the University of California, Berkeley told Space.com. "It's fun to have been able to find the first one." 

The supernova, which was discovered on Nov. 11, 2014, is located about 9.3 billion light-years away from Earth, near the edge of the observable universe. The researchers have named the distant supernova SN Refsdal in honor of the late Norwegian astrophysicist Sjur Refsdal, a pioneer of gravitational lensing studies. Due to gravitational lensing, "the supernova appears 20 times brighter than its normal brightness," study co-author Jens Hjorth, head of the Dark Cosmology Centre at the Niels Bohr Institute at the University of Copenhagen, said in a statement.
The lensing galaxy, which is about 5 billion light-years from Earth, is part of a large cluster of galaxies known MACS J1149.6+2223. In 2009, astronomers discovered that this cluster was the source of the largest known image of a spiral galaxy ever seen through a gravitational lens.

The four images of the supernova each appeared separately over the course of a few weeks. This is because light can take various paths around and through a gravitational lens, arriving at Earth at different times.

Using gravity as a lens

Gravity is created when matter warps the fabric of reality. The greater the mass of an object, the more space-time curves around that object and the stronger its gravitational pull, the discovery enshrined in Einstein's theory of general relativity, which celebrates its centennial this year.

As a result, gravity can also bend light like a lens, meaning objects see n behind powerful gravitational fields, such as those of massive galaxies, are magnified. Gravitational lensing was first discovered in 1979, and today gravitational lenses can help astronomers see features otherwise too distant and faint to detect with even the largest telescopes.

"These gravitational lenses are like a natural magnifying glass. It's like having a much bigger telescope," Kelly said in a statement. "We can get magnifications of up to 100 times by looking through these galaxy clusters."

When light is far from a gravitationally lensing mass, or if the gravitationally lensing mass is not especially large, only "weak lensing" occurs, barely distorting the light. However, when the light comes from almost exactly behind the gravitationally lensing mass, "strong lensing" can happen. 

When a strongly lensed object occupies a large patch of space — for instance, if it's a galaxy — it can get smeared into an "Einstein ring" surrounding a gravitationally lensing mass. However, strong lensing of small, pointlike items — for instance, super-bright objects known as quasars — often produces multiple images surrounding the gravitationally lensing mass, resulting in a so-called "Einstein cross."

The observations of SN Refsdal mark the first time astronomers on Earth have witnessed strong lensing of a  supernova, with four images of an exploding star arrayed as an Einstein cross.

An expanding universe

These new findings could help scientists measure the accelerating rate at which the universe is expanding, researchers say.

A computer model of the lensing cluster suggests the scientists missed chances to see the lensed supernova 50 and 10 years ago. However, the model also suggests more images of the explosion will repeat again within the next 10 years.

The timing of when all these images of the supernova arrive depends on the gravitational pull of the matter generating the gravitational lens. So, by measuring those times, the researchers hope to map how visible normal matter and invisible dark matter is distributed in the lensing galaxy.

Dark matter is currently one of the greatest mysteries in science, a poorly understood substance thought to make up five-sixths of all matter in the universe. A better understanding of how dark matter is behaving in this gravitationally lensing cluster might help shed light on the material's nature, Kelly said.

Analyzing when the images arrive could also help scientists pinpoint the rate at which the universe is expanding. Although there are already several ways to measure the cosmic expansion rate, "there has been a lot of heated debate between different methods, so it'd be interesting to see how this new technique might affect the area," Kelly said. "It's always nice to have completely independent measurements of the same quantity."

The scientists detailed their findings in the March 6 issue of the journal Science.

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8 possible explanations for those bright spots on dwarf planet Ceres

March 8, 2015 / / 0 Comments

Ceres  Excerpt from cnet.com It's a real-life mystery cliffhanger. We've come up with a list of possible reasons a large crater on the biggest object in the asteroid belt looks lit up like a Christmas tree.  We could be approachin...

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Is This a Baby Picture of a Giant Planet?

March 7, 2015 / / 0 Comments


Hubble optical image (left) and VLT infrared image (right) of the circumstellar disk surrounding HD 100546. (ESO/NASA/ESA/Ardila et al.)


Excerpt from news.discovery.com


Mommy, where do baby planets come from? There’s no storks, birds, bees, or romantic dinners for two involved in the answer to that question — regardless of size, planets are all formed in pretty much the same way: through the aggregation of material within the disk of dust and gas surrounding a young star. While how long it actually takes and just what sort of planets are most likely to form where are still topics of discussion among astronomers, the birth process of a planet is fairly well understood.

And this may be the very first image of it actually happening.

Acquired by the European Southern Observatory’s Very Large Telescope (VLT), the infrared image above (right) shows a portion of the disk of gas and dust around the star HD100546, located 335 light-years away in the constellation Musca. By physically blocking out the light from the star itself by means of an opaque screen — seen along the left side of the image — the light from the protoplanetary disk around HD 100546 can be seen, revealing a large bright clump that’s thought to be a planet in the process of formation.

If it is indeed a baby planet, it’s a big one — as large as, or perhaps even larger than, Jupiter.

A candidate protoplanet found in a disc of gas and dust around young star HD100546 (ESO)


This does raise an interesting question for astronomers because if it is a Jupiter-sized planet, it’s awfully far from its star… at least according to many current models of planetary formation. About 68 times as far from HD100546 as we are from the sun, if this planet were in our solar system it’d be located deep in the Kuiper Belt, twice as far as Pluto. That’s not where one would typically expect to find gas giants, so it’s been hypothesized that this protoplanet might have migrated outwards after initially forming closer to the star… perhaps “kicked out” by gravitational interaction with an even more massive planet.

Alternatively, it may not be a planet at all — the bright blob in the VLT image might be coming from a much more distant source. While extremely unlikely, further research will be needed to rule that possibility out.

If it’s found to be a planet, HD100546 “b” would offer scientists an unprecedented opportunity to observe a planetary formation process in action — and from a relatively close proximity as well.

According to the team’s paper, submitted to Astrophysical Journal Letters, ”What makes HD100546 particularly interesting is that 1. it would be the first imaged protoplanet that is still embedded in the gas and dust disk of its host star; and 2. it would show that planet formation does occur at large orbital separations.”

(Now all we have to do is wait a couple billion years and then show these pictures to HD100546b’s girlfriend. How embarrassing!)

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Exoplanet Imager Begins Hunt for Alien Worlds

March 7, 2015 / / 0 Comments


This infrared image shows the dust ring around the nearby star HR 4796A in the southern constellation of Centaurus.


Excerpt from news.discovery.com

By Ian O'Neill

A new instrument attached to one of the most powerful telescopes in the world has been switched on and acquired its ‘first light’ images of alien star systems and Saturn’s moon Titan.
The Spectro-Polarimetric High-contrast Exoplanet REsearch (or SPHIRES) instrument has been recently installed at the ESO’s Very Large Telescope’s already impressive suite of sophisticated instrumentation. The VLT is located in the ultra-dry high-altitude climes of the Atacama Desert in Chile.

In the observation above, an ‘Eye of Sauron‘-like dust ring surrounding the star HR 4796A in the southern constellation of Centaurus, a testament to the sheer power of the multiple technique SPHIRES will use to acquire precision views of directly-imaged exoplanets.

The biggest problem with trying to directly image a world orbiting close to its parent star is that of glare; stars are many magnitudes brighter that the reflected light from its orbiting exoplanet, so how the heck are you supposed to gain enough contrast between the bright star and exoplanet to resolve the two? The SPHIRES instrument is using a combination of three sophisticated techniques to remove a star’s glare and zero-in on its exoplanetary targets.

This infrared image of Saturn’s largest moon, Titan, was one of the first produced by the SPHERE instrument soon after it was installed on ESO’s Very Large Telescope in May 2014.
ESO 
The first technique, known as adaptive optics, is employed by the VLT itself. By firing a laser into the Earth’s atmosphere during the observation, a gauge on the turbulence in the upper atmospheric gases can be measured and the effects of which can be removed from the imagery. Any blurriness caused by our thick atmosphere can be adjusted for.

Next up is a precision coronograph inside the instrument that blocks the light from the target star. By doing this, any glare can be removed and any exoplanet in orbit may be bright enough to spot.

But the third technique, which really teases out any exoplanet signal, is the detection of different polarizations of light from the star system. The polarization of infrared light being generated by the star and the infrared glow from the exoplanet are very subtle. SPHIRES can differentiate between the two, thereby further boosting the observation’s contrast.

“SPHERE is a very complex instrument. Thanks to the hard work of the many people who were involved in its design, construction and installation it has already exceeded our expectations. Wonderful!” said Jean-Luc Beuzit, of the Institut de Planétologie et d’Astrophysique de Grenoble, France and Principal Investigator of SPHERE, in an ESO press release.

The speed and sheer power of SPHIRES will be an obvious boon to astronomers zooming in on distant exoplanets, aiding our understanding of these strange new worlds.


The star HR 7581 (Iota Sgr) was observed in SPHERE survey mode (parallel observation in the near infrared with the dual imaging camera and the integral field spectrograph ). A very low mass star, more than 4000 times fainter that its parent star, was discovered orbiting Iota Sgr at a tiny separation of 0.24". This is a vital demonstration of the power of SPHERE to image faint objects very close to bright ones.
ESO

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Astronomers Find Massive Exoplanet With Four Parent Stars

March 6, 2015 / / 0 Comments

Artist rendering of the system 30 Ari with its exoplanet and four stars. Excerpt from techtimes.com By Dianne Depra  Researchers seeking to study the complexities of exoplanets with multiple stars have found a new system with four. Cal...

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Astronomers find star speeding out of the galaxy

March 5, 2015 / / 0 Comments





(Reuters) - Astronomers have found a star hurtling through the galaxy faster than any other, the result of being blasted away by the explosion of a massive partner star, researchers said on Thursday.
The star, known as US 708, is traveling at about 746 miles (1,200 km) per second, fast enough to actually leave the Milky Way galaxy in about 25 million years, said astronomer Stephan Geier with Germany-based European Southern Observatory, which operates three telescopes in Chile.

"At that speed you could travel from Earth to the moon in five minutes," noted University of Hawaii astronomer Eugene Magnier.
US 708 is not the first star astronomers have found that is moving fast enough to escape the galaxy, but it is the only one so far that appears to have been slingshot in a supernova explosion.

The 20 other stars discovered so far that are heading out of the galaxy likely got their impetus from coming too close to the supermassive black hole that lives at the center of the Milky Way, scientists report in an article in this week’s edition of the journal Science.

Before it was sent streaming across the galaxy, US 708 was once a cool giant star, but it was stripped of nearly all of its hydrogen by a closely orbiting partner. Scientists suspect it was this feeding that triggered the partner’s detonation.

If confirmed, these types of ejected stars may provide more insight into how supernova explosions occur. Since the explosions give off a fairly standard amount of radiation, scientists can calculate their distances by measuring how bright or dim they appear and determine how fast the universe is expanding.

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