. Energy News .




.
EXO WORLDS
Planet-Forming Disk Turns Off Lights, Locks Doors
by Staff Writers
San Diego CA (SPX) Jul 06, 2012

Artist's conceptualization of the dusty TYC 8241 2652 system as it might have appeared several years ago when it was emitting large amounts of excess infrared radiation. Credit: Gemini Observatory/AURA artwork by Lynette Cook. For a larger version of this image please go here.

That surprise you feel when your favorite store turns off its lights, locks up its doors, and suddenly, for no apparent reason, goes out of business? That's just how astronomers felt recently when a dusty disk of rocky debris around a nearby star abruptly shut down and by all appearances went out of business.

The star - designated TYC 8241 2652 and a young analog of our Sun - only a few years ago displayed all of the characteristics of hosting a solar system in the making. Now, it has transformed completely: very little of the warm dusty material thought to originate from collisions of rocky planets is apparent - it's a mystery that has astronomers baffled.

Carl Melis of the University of California, San Diego, led the discovery team, whose report is published in the July 5th issue of the journal Nature. He said, "It's like the classic magician's trick: now you see it, now you don't. Only in this case we're talking about enough dust to fill an inner solar system and it really is gone!"

Co-author Ben Zuckerman of the University of California Los Angeles, observed, "It's as if you took a conventional picture of the planet Saturn today and then came back two years later and found that its rings had disappeared."

The dusty disk at TYC 8241 2652 was first seen by the NASA Infrared Astronomical Satellite (IRAS) in 1983, and remained brightly glowing for 25 years. Like Earth, warm dust absorbs the energy of visible starlight (sunlight) and reradiates that heat energy as infrared radiation.

An infrared image obtained at the Gemini telescope in Chile on May 1, 2012 - just as the paper was being accepted by Nature - confirmed that the warm dust has now been gone for 2.5 years.

"A perplexing thing about this discovery is that we don't have a really satisfactory explanation to address what happened around this star. The disappearing act appears to be independent of the star itself, as there is no evidence to suggest that the star zapped the dust with some sort of mega-flare or any other violent event," said Melis.

Zuckerman, who has been investigating circumstellar disks (debris disks around stars) since the 1980s, noted that "the dust disappearance at TYC 8241 2652 was so bizarre and so quick, initially I figured that our observations must simply be in error in some strange way."

Norm Murray, Director of the Canadian Institute for Theoretical Astrophysics, who was not part of the research group, said, "The history of astronomy has shown that events that are not predicted and hard to explain can be game-changers".

The lack of an existing model for what is going on around this star is forcing astronomers to rethink what happens within young solar systems in the making.

"Although we've identified a couple of mechanisms that are potentially viable, none are really compelling," said Melis. "In one case, gas produced in the impact that released the dust helps to quickly drag the dust particles into the star and thus to their doom.

"In another possibility, collisions of large rocks left over from an original major impact provide a fresh infusion of dust particles into the disk which then instigate a runaway process where small grains chip into oblivion both themselves and also larger grains."

Major dusty regions such as the asteroid belt and another located out beyond the orbit of Neptune are known to exist in our own solar system. Nearly 30 years ago, NASA's Infrared Astronomical Satellite (IRAS) first discovered similar regions orbiting other stars.

Now hundreds of stars similar to our Sun are known to emit an excess of infrared radiation that is usually attributed to dusty materials orbiting the star in what are called debris disks.

It is believed that this material results from planetary system formation and is due to collisions and reprocessing of objects like the comets and asteroids that are part of our own solar system. But nothing like the disappearing dust disk at TYC 8241 2652 had ever been seen during these three decades.

The result is based upon multiple sets of observations of TYC 8241 2652 obtained with the Thermal-Region Camera Spectrograph (T-ReCS) on the Gemini South telescope in Chile, the IRAS satellite, the Wide-field Infrared Survey Explorer (WISE) satellite, NASA's Infrared Telescope on Mauna Kea in Hawai`i, the Herschel Space Telescope of the European Space Agency, and AKARI (a Japanese/ESA infrared satellite).

TYC 8241 2652 lies in the direction of the constellation of Centaurus. Observations by Australian co-authors Simon Murphy and Michael Bessell with the Australian National University's 2.3-meter telescope established that the star is roughly 10 million years old and 450 light years distant.

Related Links
Gemini Observatory
Lands Beyond Beyond - extra solar planets - news and science
Life Beyond Earth




.
.
Get Our Free Newsletters Via Email
...
Buy Advertising Editorial Enquiries




.

. Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle



EXO WORLDS
Dramatic change spotted on a faraway planet
Baltimore MD (SPX) Jul 02, 2012
Astronomers using the NASA/ESA Hubble Space Telescope have seen dramatic changes in the upper atmosphere of a faraway planet. Just after a violent flare on its parent star bathed it in intense X-ray radiation, the planet's atmosphere gave off a powerful burst of evaporation. The observations give a tantalising glimpse of the changing climates and weather on planets outside our Solar System. ... read more


EXO WORLDS
ESA-China collaboration takes Earth observation to new heights

Satellite research reveals smaller volcanoes could cool climate

NASA Satellites Examine a Powerful Summer Storm

Bottleneck off the Orkney Islands

EXO WORLDS
Announcement of ACRIDS product line for Precision Airdrop Systems

SSTL announces exactView-1 satellite launch date

Galileo pathfinder GIOVE-A retires

ESA extends its navigation lab in readiness for Galileo testing

EXO WORLDS
Taiwan indicts loggers for axing 2000-year-old trees

Study Slashes Deforestation Carbon Emission Estimate

Scientists develop first satellite deforestation tracker for whole of Latin America

Scientists reconstruct pre-Columbian human effects on the Amazon Basin

EXO WORLDS
Denmark can triple its biomass production and improve the environment

Researchers tap into genetic reservoir of heat-loving bacteria

Prairie cordgrass: Highly underrated

New loo turns poo into power

EXO WORLDS
Japanese Energy Supply Gets FiT With Solar Bonds

New England Clean Energy Wins Two Solarize Projects

TUV Rheinland PTL's New Services Support Large-Scale Solar Power Plants

Europe Unlikely to Follow US Lead in Imposing Duties on China PV Imports

EXO WORLDS
U.S moves massive wind farm plan forward

Belgium wind farm a go after EIB loan

Opponents force Wales wind farm hearings

Toward super-size wind turbines: Bigger wind turbines do make greener electricity

EXO WORLDS
Huge Australian coal mine wins conditional approval

Russia expands presence on Spitsbergen

Australia scraps coal port expansion

Trapped China miner found after 17 days: state media

EXO WORLDS
EU parliament condemns China forced abortions

China vows crackdown after latest protest

Huge China art gift boosts Hong Kong culture district

Tension as China scraps factory plan


Memory Foam Mattress Review

Newsletters :: SpaceDaily Express :: SpaceWar Express :: TerraDaily Express :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News

.

The content herein, unless otherwise known to be public domain, are Copyright 1995-2012 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement