Subscribe free to our newsletters via your
. 24/7 Space News .




EXO WORLDS
NASA's Hubble Space Telescope Finds Dead Stars Polluted with Planet Debris
by Staff Writers
Baltimore MD (SPX) May 13, 2013


This is an artist's impression of a white dwarf (burned-out) star accreting rocky debris left behind by the star's surviving planetary system. It was observed by Hubble in the Hyades star cluster. At lower right, an asteroid can be seen falling toward a Saturn-like disk of dust that is encircling the dead star. Infalling asteroids pollute the white dwarf's atmosphere with silicon. Credit: NASA, ESA, and G. Bacon (STScI). For a larger version of this image please go here.

NASA's Hubble Space Telescope has found the building blocks for Earth-sized planets in an unlikely place-- the atmospheres of a pair of burned-out stars called white dwarfs.

These dead stars are located 150 light-years from Earth in a relatively young star cluster, Hyades, in the constellation Taurus. The star cluster is only 625 million years old. The white dwarfs are being polluted by asteroid-like debris falling onto them.

Hubble's Cosmic Origins Spectrograph observed silicon and only low levels of carbon in the white dwarfs' atmospheres. Silicon is a major ingredient of the rocky material that constitutes Earth and other solid planets in our solar system. Carbon, which helps determine properties and origin of planetary debris, generally is depleted or absent in rocky, Earth-like material.

"We have identified chemical evidence for the building blocks of rocky planets," said Jay Farihi of the University of Cambridge in England. He is lead author of a new study appearing in the Monthly Notices of the Royal Astronomical Society.

"When these stars were born, they built planets, and there's a good chance they currently retain some of them. The material we are seeing is evidence of this. The debris is at least as rocky as the most primitive terrestrial bodies in our solar system."

This discovery suggests rocky planet assembly is common around stars, and it offers insight into what will happen in our own solar system when our sun burns out 5 billion years from now.

Farihi's research suggests asteroids less than 100 miles (160 kilometers) wide probably were torn apart by the white dwarfs' strong gravitational forces. Asteroids are thought to consist of the same materials that form terrestrial planets, and seeing evidence of asteroids points to the possibility of Earth-sized planets in the same system.

The pulverized material may have been pulled into a ring around the stars and eventually funneled onto the dead stars. The silicon may have come from asteroids that were shredded by the white dwarfs' gravity when they veered too close to the dead stars.

"It's difficult to imagine another mechanism than gravity that causes material to get close enough to rain down onto the star," Farihi said.

By the same token, when our sun burns out, the balance of gravitational forces between the sun and Jupiter will change, disrupting the main asteroid belt. Asteroids that veer too close to the sun will be broken up, and the debris could be pulled into a ring around the dead sun.

According to Farihi, using Hubble to analyze the atmospheres of white dwarfs is the best method for finding the signatures of solid planet chemistry and determining their composition.

"Normally, white dwarfs are like blank pieces of paper, containing only the light elements hydrogen and helium,"Farihi said. "Heavy elements like silicon and carbon sink to the core. The one thing the white dwarf pollution technique gives us that we just won't get with any other planet-detection technique is the chemistry of solid planets."

The two "polluted" Hyades white dwarfs are part of the team's search of planetary debris around more than 100 white dwarfs, led by Boris Gansicke of the University of Warwick in England.

Team member Detlev Koester of the University of Kiel in Germany is using sophisticated computer models of white dwarf atmospheres to determine the abundances of various elements that can be traced to planets in the Hubble spectrograph data.

Fahiri's team plans to analyze more white dwarfs using the same technique to identify not only the rocks' composition, but also their parent bodies.

.


Related Links
Hubble at NASA
Lands Beyond Beyond - extra solar planets - news and science
Life Beyond Earth






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
The Great Exoplanet Debate
Moffett Field CA (SPX) May 07, 2013
At the 2012 Astrobiology Science Conference, Astrobiology Magazine hosted a plenary session titled: "Expanding the Habitable Zone: The Hunt for Exoplanets Now and Into the Future." Originally formulated as part of our "Great Debate" series, this panel of exoplanet hunters and thinkers held a lively discussion about some of the most important issues facing the search for and understanding of alie ... read more


EXO WORLDS
Northrop Grumman Completes Lunar Lander Study for Golden Spike Company

Scientists Use Laser to Find Soviet Moon Rover

Characterizing The Lunar Radiation Environment

Russia rekindles Moon exploration program, intends setting up first human outposts there

EXO WORLDS
NASA Curiosity Rover Team Selects Second Drilling Target on Mars

Opportunity Making Smallest Turn Yet, As Dust Storm Affects Rover

More than 78,000 people apply for one-way trip to Mars

Austria Aims For Mars Via Morocco

EXO WORLDS
Researchers use graphene quantum dots to detect humidity and pressure

Outside View: Patents laws and suffering innovators

Glow-in-the-Dark Plants on the ISS

Russia Confirms Plans to Send Sarah Brightman to Space

EXO WORLDS
China launches communications satellite

On Course for Shenzhou 10

Yuanwang III, VI depart for space-tracking missions

Shenzhou's Shadow Crew

EXO WORLDS
The fourth Automated Transfer Vehicle is ready to meet up with its Ariane 5

NASA to pay Russia $424 mln more for lift into space

NASA Extends Crew Flight Contract with Russian Space Agency

Cargo spaceship docks with ISS despite antenna mishap

EXO WORLDS
NASA Awards Contract to Modify Mobile Launcher

Angara Rocket Launch Delayed to 2014

ESA's Vega launcher scores new success with Proba-V

European Vega rocket launch delayed due to weather

EXO WORLDS
NASA's Hubble Space Telescope Finds Dead Stars Polluted with Planet Debris

The Great Exoplanet Debate

NASA's Spitzer Puts Planets in a Petri Dish

Two New Exoplanets Detected with Kepler, SOPHIE and HARPS-N

EXO WORLDS
One order of steel; hold the greenhouse gases

Cloud computing is silver lining for Russian firms

Another 'trophy' for the chemistry cabinet

Researcher Construct Invisibility Cloak for Thermal Flow




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - 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