Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

2 Earth-sized bodies with oxygen rich atmospheres found -- but they're stars not planets

13.11.2009
Astrophysicists find 2 Earth-sized bodies with oxygen rich atmospheres - only snag is they're stars not planets

Astrophysicists at the University of Warwick and Kiel University have discovered two earth sized bodies with oxygen rich atmospheres – however there is a bit of a disappointing snag for anyone looking for a potential home for alien life, or even a future home for ourselves, as they are not planets but are actually two unusual white dwarf stars.

The two white dwarf stars SDSS 0922+2928 and SDSS 1102+2054 are 400 and 220 light years from Earth. They are both the remnants of massive stars that are at the end of their stellar evolution having consumed all the material they had available for nuclear fusion.

Theoretical models suggest that massive stars (around 7 – 10 times the mass of our own Sun) will consume all of their hydrogen, helium and carbon, and end their lives either as white dwarfs with very oxygen-rich cores, or undergo a supernova and collapse into neutron stars. Finding such oxygen-rich white dwarfs would be an important confirmation of the models.

Unfortunately, almost all white dwarfs have hydrogen and/or helium envelopes that, while low in mass, are sufficiently thick to shield the core from direct view. However should such a core lose its remaining hydrogen envelope, astrophysicists could then detect an extremely oxygen-rich spectrum from the surface of the white dwarf.

Searching within an astronomical data set of the Sloan Digital Sky Survey (SDSS), the University of Warwick and Kiel University astrophysicists did indeed discover two white dwarfs with large atmospheric oxygen abundances.

Lead author on the paper, astrophysicist Dr. Boris Gänsicke from the University of Warwick, said:

"These surface abundances of oxygen imply that these are white dwarfs displaying their bare oxygen-neon cores, and that they may have descended from the most massive progenitors stars in that class."

Most stellar models producing white dwarfs with such oxygen and neon cores also predict that a sufficiently thick carbon-rich layer should surround the core and avoid upward diffusion of large amounts of oxygen. However, calculations also show that the thickness of this layer decreases the closer the progenitor star is to upper mass limit for stars ending their lives as white dwarfs. Hence one possibility for the formation of SDSS 0922+2928 and SDSS 1102+2054 is that they descended from the most massive stars avoiding core-collapse, in which case they would be expected to be very massive themselves. However current data is insufficient to provide any unambiguous measure of the masses of these two unusual white dwarves.

The full paper "Two white dwarfs with oxygen-rich atmospheres" will be published online by the journal Science on November 12th 2009 at 2pm EST and is written by Dr Boris Gänsicke, Jonathan Girven, Professor Tom Marsh, and Dr Danny Steeghs all of Department of Physics at University of Warwick in the UK and Detlev Koester of the University of Kiel in Germany.

Copies of the embargoed Science paper are available to reporters from the AAAS Office of Public - contact +1-202-326-6440 or scipak@aaas.org

For further information please contact:

Dr Boris Gänsicke, Department of Physics , University of Warwick
+44 (0)2476 574741
Boris.Gaensicke@warwick.ac.uk
Peter Dunn, Head of Communications
Communications Office, University of Warwick,
+44 (0)24 76 523708 or +44 (0)7767 655860
email: p.j.dunn@warwick.ac.uk

Dr. Boris Gänsicke | EurekAlert!
Further information:
http://www.warwick.ac.uk

More articles from Physics and Astronomy:

nachricht Breakthrough with a chain of gold atoms
17.02.2017 | Universität Konstanz

nachricht New functional principle to generate the „third harmonic“
16.02.2017 | Laser Zentrum Hannover e.V.

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Biocompatible 3-D tracking system has potential to improve robot-assisted surgery

17.02.2017 | Medical Engineering

Real-time MRI analysis powered by supercomputers

17.02.2017 | Medical Engineering

Antibiotic effective against drug-resistant bacteria in pediatric skin infections

17.02.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>