stars Archives - Page 12 of 16

July 5, 2012December 23, 2015

WISE Spies a Hunter’s Flame

A vast star-forming cloud of gas and dust in the constellation Orion shines brightly in this image from NASA’s WISE space telescope, where infrared light is represented in visible wavelengths. It’s part of a recent data release from WISE, a trove of infrared images acquired during the telescope’s second sky scan from August to September of 2010 — just as it began to run out of its essential cryogenic coolant.

Shining brightly in infrared radiation, the Flame nebula (NGC 2024) is at the heart of the cloud. Just below it is the reflection nebula NGC 2023, and the small, bright loop protruding from the edge of the gas and dust cloud just to its lower right is the Horsehead nebula — whose famous equine profile appears quite different in infrared light than it does in visible.

The two bright blue stars at the upper right portion of the image are both stars in Orion’s belt. Alnitak, the brighter one closer to the Flame nebula, is a multiple star system located 736 light-years away whose stellar wind is responsible for ionizing the Flame nebula and causing it to shine in infrared. Alnilam, the dimmer star at the uppermost corner, is a blue supergiant 24 times the radius of our Sun and 275,000 times as bright, but 1,980 light-years distant.

The red arc at lower right is the bow shock of Sigma Orionis, a multiple-star system that’s hurtling through space at a speed of 5,260,000 mph (2,400 kilometers per second). As its stellar wind impacts the interstellar medium and piles up before it, an arc of infrared-bright radiation is emitted.

Sigma Orionis is also the star responsible for the glow of the Horsehead nebula.

This rich astronomical scene is an expanded view from WISE’s previously-released image of the region (at right) which used data from only three of its four infrared detectors. In contrast, all four detectors were used in the image above, making more of the nebulae’s intricate structures visible as well as providing comparative information for researchers.

“If you’re an astronomer, then you’ll probably be in hog heaven when it comes to infrared data,” said Edward (Ned) Wright of UCLA, the principal investigator of the WISE mission. “Data from the second sky scan are useful for studying stars that vary or move over time, and for improving and checking data from the first scan.”

Read more on the NASA news release here.

Top and right images: NASA/JPL-Caltech/WISE team. Horsehead nebula visible light image was taken with the 0.9-meter telescope at Kitt Peak National Observatory. Photo credit & copyright: Nigel Sharp (NOAO), KPNO, AURA, NSF. Comparison by J. Major/Universe Today.

June 27, 2012December 23, 2015

How to Measure a Hot Jupiter

An international team of astronomers has figured out a way to determine details of an exoplanet’s atmosphere from 50 light-years away… even though the planet doesn’t transit the face of its star as seen from Earth.

Tau Boötis b is a “hot Jupiter” type of exoplanet, 6 times more massive than Jupiter. It was the first planet to be identified orbiting its parent star, Tau Boötis, located 50 light-years away. It’s also one of the first exoplanets we’ve known about, discovered in 1996 via the radial velocity method — that is, Tau Boötis b exerts a slight tug on its star, shifting its position enough to be detectable from Earth. But the exoplanet doesn’t pass in front of its star like some others do, which until now made measurements of its atmosphere impossible.

Today, an international team of scientists working with the Very Large Telescope (VLT) at ESO’s Paranal Observatory in Chile have announced the success of a “clever new trick” of examining such non-transiting exoplanet atmospheres. By gathering high-quality infrared observations of the Tau Boötis system with the VLT’s CRIRES instrument the researchers were able to differentiate the radiation coming from the planet versus that emitted by its star, allowing the velocity and mass of Tau Boötis b to be determined.

“Thanks to the high quality observations provided by the VLT and CRIRES we were able to study the spectrum of the system in much more detail than has been possible before,” said Ignas Snellen with Leiden Observatory in the Netherlands, co-author of the research paper. “Only about 0.01% of the light we see comes from the planet, and the rest from the star, so this was not easy.”

Using this technique, the researchers determined that Tau Boötis b’s thick atmosphere contains carbon monoxide and, curiously, exhibits cooler temperatures at higher altitudes — the opposite of what’s been found on other hot Jupiter exoplanets.

“Maybe one day we may even find evidence for biological activity on Earth-like planets in this way.”

– Ignas Snellen, Leiden Observatory, the Netherlands

In addition to atmospheric details, the team was also able to use the new method to determine Tau Boötis b’s mass and orbital angle — 44 degrees, another detail not previously identifiable.

“The new technique also means that we can now study the atmospheres of exoplanets that don’t transit their stars, as well as measuring their masses accurately, which was impossible before,” said Snellen. “This is a big step forward.

“Maybe one day we may even find evidence for biological activity on Earth-like planets in this way.”

This research was presented in a paper “The signature of orbital motion from the dayside of the planet Tau Boötis b”, to appear in the journal Nature on June 28, 2012.

Milky Way to Concordia Base… Come In, Concordia Base…

This stunning photo of the Milky Way was captured from what may be the coldest and most isolated research facility on Earth: the French-Italian Concordia Base station, located at 3,200 meters (nearly 10,500 feet) altitude on the Antarctic plateau, 1,670 km (1,037 miles) from the geographic south pole.

Taken by Dr. Alexander Kumar, a doctor, researcher and photographer who’s been living at the Base since January, the image shows the full beauty of the sky above the southern continent — a sky that doesn’t see the Sun from May to August.

During the winter months no transportation can be made to or from Concordia Base — no deliveries or evacuations, not for any reason. The team there is truly alone, very much like future space explorers will one day be. This isolation is one reason that Concordia is used by ESA for research for missions to Mars.

Of course, taking photos outside is no easy task. Temperatures outside the Base in winter can drop down to -70ºC (-100ºF)!

Still, despite the isolation, darkness and cold, Dr. Kumar finds inspiration in his surroundings.

“The dark may cause fear, but if you take the time to adapt and look within it, you never know what you may find – at the bottom of the ocean, in the night sky, or under your bed in the middle of the night,” writes Kumar on the Concordia blog. “If you don’t overcome your fear of the ‘unknown’ and ‘monsters’, you will never see marvellous secrets hidden in the dark.

“I hope this photo inspires you too for the days, weeks and months ahead. In terms of the space exploration we are only beginning. We have to continue pushing out into the great beyond.”

Image credits: ESA/IPEV/PNRA – A. Kumar

May 16, 2012December 23, 2015

The Big Dipper Like You’ve Never Seen It Before!

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All right, it may look just like any other picture you’ve ever seen of the Big Dipper. Maybe even a little less impressive, in fact. But, unlike any other picture, this one was taken from 290 million km away by NASA’s Juno spacecraft en route to Jupiter, part of a test of its Junocam instrument! Now that’s something new concerning a very old lineup of stars!

“I can recall as a kid making an imaginary line from the two stars that make up the right side of the Big Dipper’s bowl and extending it upward to find the North Star,” said Scott Bolton, principal investigator of NASA’s Juno mission. “Now, the Big Dipper is helping me make sure the camera aboard Juno is ready to do its job.”

567922main_junospacecraft0711 — Diagram of the Juno spacecraft (NASA/JPL)

The image is a section of a larger series of scans acquired by Junocam between 20:23 and 20:56 UTC (3:13 to 3:16 PM EST) on March 14, 2012. Still nowhere near Jupiter, the purpose of the imaging exercise was to make sure that Junocam doesn’t create any electromagnetic interference that could disrupt Juno’s other science instruments.

In addition, it allowed the Junocam team at Malin Space Science Systems in San Diego, CA to test the instrument’s Time-Delay Integration (TDI) mode, which allows image stabilization while the spacecraft is in motion.

Because Juno is rotating at about 1 RPM, TDI is crucial to obtaining focused images. The images that make up the full-size series of scans were taken with an exposure time of 0.5 seconds, and yet the stars (brightened above by the imaging team) are still reasonably sharp… which is exactly what the Junocam team was hoping for.

“An amateur astrophotographer wouldn’t be very impressed by these images, but they show that Junocam is correctly aligned and working just as we expected”, said Mike Caplinger, Junocam systems engineer.

As well as the Big Dipper, Junocam also captured other stars and asterisms, such as Vega, Canopus, Regulus and the “False Cross”. (Portions of the imaging swaths were also washed out by sunlight but this was anticipated by the team.)

These images will be used to further calibrate Junocam for operation in the low-light environment around Jupiter, once Juno arrives in July 2016.

Read more about the Junocam test on the MSSS news page here.

As of May 10, Juno was approximately 251 million miles (404 million kilometers) from Earth. Juno has now traveled 380 million miles (612 million kilometers) since its launch on August 5, 2011 and is currently traveling at a velocity of 38,300 miles (61,600 kilometers) per hour relative to the Sun.

Watch a video of the Juno launch here, taken by yours truly from the press site at Kennedy Space Center!

May 14, 2012December 23, 2015

A Sword of Stars

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Like the blade of a magical weapon from a fantasy tale, the northern edge of spiral galaxy NGC 891 is captured by the Hubble Space Telescope, glowing with the light of billions of stars and interwoven with dark clouds of dust and cold gas.

In reality this cosmic blade is enormous. About the same size as our galaxy, NGC 891 is approximately 100,000 light-years in diameter, making the section visible here around 40,000 light-years in length.

Unlike the Milky Way, however, NGC 891 is unbarred and also exhibits many more filaments of dark gas and dust. Astronomers suggest that these are the result of star formation and supernovae, both of which can expel vast amounts of interstellar material far out into space.

The few bright stars in the foreground are located in our own galaxy.

NGC 891 is located in the constellation Andromeda and lies about 30 million light-years away… that means the light captured by Hubble’s Advanced Camera for Surveys to create the image above began its journey 35 million years after the asteroid impact that led to the extinction of the dinosaurs, and about 26 million years before our ancient African ancestors began walking upright. That may sound like a long trip but, as Douglas Adams so eloquently said, “that’s just peanuts to space!”

The Secret Origin Story of Brown Dwarfs

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Sometimes called failed stars, brown dwarfs straddle the line between star and planet. Too massive to be “just” a planet, but lacking enough material to start fusion and become a full-fledged star, brown dwarfs are sort of the middle child of cosmic objects. Only first detected in the 1990s, their origins have been a mystery for astronomers. But a researchers from Canada and Austria now think they have an answer for the question: where do brown dwarfs come from?

If there’s enough mass in a cloud of cosmic material to start falling in upon itself, gradually spinning and collapsing under its own gravity to compress and form a star, why are there brown dwarfs? They’re not merely oversized planets — they aren’t in orbit around a star. They’re not stars that “cooled off” — those are white dwarfs (and are something else entirely.) The material that makes up a brown dwarf probably shouldn’t have even had enough mass and angular momentum to start the whole process off to begin with, yet they’re out there… and, as astronomers are finding out now that they know how to look for them, there’s quite a lot.

So how did they form?

According to research by Shantanu Basu of the University of Western Ontario and Eduard I. Vorobyov from the University of Vienna in Austria and Russia’s Southern Federal University, brown dwarfs may have been flung out of other protostellar disks as they were forming, taking clumps of material with them to complete their development.

Basu and Vorobyov modeled the dynamics of protostellar disks, the clouds of gas and dust that form “real” stars. (Our own solar system formed from one such disk nearly five billion years ago.) What they found was that given enough angular momentum — that is, spin — the disk could easily eject larger clumps of material while still having enough left over to eventually form a star.

Basu-Vorobyov model — Model of how a clump of low-mass material gets ejected from a disk (S. Basu/E. Vorobyev)

The ejected clumps would then continue condensing into a massive object, but never quite enough to begin hydrogen fusion. Rather than stars, they become brown dwarfs — still radiating heat but nothing like a true star. (And they’re not really brown, by the way… they’re probably more of a dull red.)

In fact a single protostellar disk could eject more than one clump during its development, Basu and Vorobyov found, leading to the creation of multiple brown dwarfs.

If this scenario is indeed the way brown dwarfs form, it stands to reason that the Universe may be full of them. Since they are not very luminous and difficult to detect at long distances, the researchers suggest that brown dwarfs may be part of the answer to the dark matter mystery.

“There could be significant mass in the universe that is locked up in brown dwarfs and contribute at least part of the budget for the universe’s missing dark matter,” Basu said. “And the common idea that the first stars in the early universe were only of very high mass may also need revision.”

Based on this hypothesis, with the potential number of brown dwarfs that could be in our galaxy alone we may find that these “failed stars” are actually quite successful after all.

The team’s research paper was accepted on March 1 into The Astrophysical Journal.

Read more on the University of Western Ontario’s news release here.

May 2, 2012December 23, 2015

Where All The Hottest Stars Gather

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An ESO telescope captures a group of hot young stars that would outshine any Hollywood party!

At the upper left of this image is the star cluster NGC 6604, a grouping of hot young stars within a larger collection located in the sky near the much more famous Eagle Nebula (of “Pillars of Creation” fame.) The young stars, which burn bright and blue, are helping make a new generation of stars with their strong stellar winds, which condense nearby gas and dust into even more star-forming regions.

Eventually the new stars will replace the ones seen here, which, although big and bright, will quickly burn through their stellar fuel and fade. Such is the life cycle of massive stars — live fast and die young.

This image was acquired by the MPG/ESO 2.2-meter telescope at the European Southern Observatory’s La Silla Observatory in Chile. NGC 6604 is about 5,500 light-years from Earth, located in the constellation Serpens. Read more on the ESO news release here.

April 18, 2012December 23, 2015

Grab a seat for the Celestial Lights show!

Painstakingly assembled from over 150,000 digital photos taken over the course of eight months, this stunning time-lapse video of aurora-filled Arctic skies is the latest creation by photo/video artist Ole C. Salomonsen. Take a moment, turn up the sound, sit back and enjoy the show!

This is Ole’s second video project. The footage was shot on location in parts of Norway, Finland and Sweden from September 2011 to April 2012, and shows the glorious effects that the Sun’s increasing activity has had on our planet’s upper atmosphere.

Ole writes on his Vimeo page:

The video is a merge of two parts; the first part contains some more wild and aggressive auroras, as well as a few Milky Way sequences, hence either auroras are moving fast because they are or they are fast due to motion of the Milky Way / stars. Still, some of the straight-up shots are very close to real-time speed — although auroras mostly are slower, she can also be FAST!

The second part has some more slow and majestic auroras, where I have focused more on composition and foreground. The music should give you a clear indication of where you are.

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The music was provided by Norwegian composer Kai-Anders Ryan.

Ole’s “hectic” aurora season is coming to a close now that the Sun is rising above the horizon in the Arctic Circle, and he figured that it was a good time to release the video. It will also be available on 4K Digital Cinema on request.

“Hope you like the video, and that you by watching it are able to understand my fascination and awe for this beautiful celestial phenomenon,” says Ole.

You can follow Ole’s work on Facebook at facebook.com/arcticlightphoto, and check out his website here.

March 30, 2012December 23, 2015

Hubble Gets Best Look Yet At Messier 9

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First discovered by Charles Messier in 1764, the globular cluster Messier 9 is a vast swarm of ancient stars located 25,000 light-years away, close to the center of the galaxy. Too distant to be seen with the naked eye, the cluster’s innermost stars have never been individually resolved… until now.

This image from the Hubble Space Telescope is the most detailed view yet into Messier 9, capturing details of over 250,000 stars within it. Stars’ shape, size and color can be determined — giving astronomers more clues as to what the cluster’s stars are made of. (Download a large 10 mb JPEG file here.)

Hot blue stars as well as cooler red stars can be seen in Messier 9, along with more Sun-like yellow stars.

Unlike our Sun, however, Messier 9’s stars are nearly ten billion years old — twice the Sun’s age — and are made up of much less heavy elements.

Since heavy elements (such as carbon, oxygen and iron) are formed inside the cores of stars and dispersed into the galaxy when the stars eventually go supernova, stars that formed early on were birthed from clouds of material that weren’t yet rich in such elements.

Zoom into the Messier 9 cluster with a video from NASA and the European Space Agency below:

The Hubble Space Telescope is a project of international cooperation between ESA and NASA. See more at www.spacetelescope.org.

Image credit: NASA & ESA. Video: NASA, ESA, Digitized Sky Survey 2, N. Risinger (skysurvey.org)

March 22, 2012December 23, 2015

VISTA View Is Chock Full Of Galaxies

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See all those tiny points of light in this image? Most of them aren’t stars; they’re entire galaxies, seen by the European Southern Observatory’s VISTA survey telescope located at the Paranal Observatory in Chile.

This is a combination of over 6000 images taken with a total exposure time of 55 hours, and is the widest deep view of the sky ever taken in infrared light.

The galaxies in this VISTA image are only visible in infrared light because they are very far away. The ever-increasing expansion rate of the Universe shifts the light coming from the most distant objects (like early galaxies) out of visible wavelengths and into the infrared spectrum.

(See a full-size version — large 253 mb file.)

ESO’s VISTA (Visual and Infrared Survey Telescope for Astronomy) telescope is the world’s largest and most powerful infrared observatory, and has the ability to peer deep into the Universe to reveal these incredibly distant, incredibly ancient structures.

By studying such faraway objects astronomers can better understand how the structures of galaxies and galactic clusters evolved throughout time.

The region seen in this deep view is an otherwise “unremarkable” and apparently empty section of sky located in the constellation Sextans.