Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Can life emerge on planets around cooling stars?

30.11.2012
Astronomers find planets in strange places and wonder if they might support life. One such place would be in orbit around a white or brown dwarf. While neither is a star like the sun, both glow and so could be orbited by planets with the right ingredients for life.
No terrestrial, or Earth-like planets have yet been confirmed orbiting white or brown dwarfs, but there is no reason to assume they don’t exist. However, new research by Rory Barnes of the University of Washington and René Heller of Germany’s Leibniz Institute for Astrophysics Potsdam hints that planets orbiting white or brown dwarfs will prove poor candidates for life.

White dwarfs are the hot cores of dead stars and brown dwarfs are failed stars, objects not massive enough to start nuclear burning as the sun does. In theory, both can be bright enough to theoretically support a habitable zone — that swath of space just right for an orbiting planet’s surface water to be in liquid form, thus giving life a chance.

The inner edge of that just-right zone is where a planet starts to become a runaway greenhouse, such as Venus. That heating phenomenon removes the planet’s surface water and all chance of life — of habitability — is forever lost.

White and brown dwarfs share a common characteristic that sets them apart from normal stars like the sun: They slowly cool and become less luminous over time. And as they cool, their habitable zones gradually shrink inward. Thus, a planet that is found in the center of the habitable zone today must previously have spent time near the zone’s deadly inner edge.

Because of their past, such planet would “face a difficult path to habitability,” Barnes said, even if they’re discovered right in that habitable zone. Call it a sort of cosmic background check, revealing that the worlds probably lost the means to host life long before they became habitable zone residents.

“These planets, if we find them today in a current habitable zone, previously had to have gone through a phase which sterilized them forever,” Barnes said. Heller added, “So, even if they are located in the habitable zone today, they are dead.”

Barnes is the lead author of a paper published in November in the journal Astrobiology; and Heller is co-author.

For more information, contact Barnes at 206-543-8979 or rory@astro.washington.edu; or Heller at (0049) 331-7499-683 or rheller@aip.de

Rory Barnes | EurekAlert!
Further information:
http://www.washington.edu

More articles from Physics and Astronomy:

nachricht The random raman laser: A new light source for the microcosmos
05.05.2015 | The Optical Society

nachricht A New Gateway to the Microcosmos
05.05.2015 | Max-Planck-Institut für Quantenoptik

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: The random raman laser: A new light source for the microcosmos

Texas A&M University researchers demonstrate how a narrow-band strobe light source for speckle-free imaging has the potential to reveal microscopic forms of life

In modern microscope imaging techniques, lasers are used as light sources because they can deliver fast pulsed and extremely high-intensity radiation to a...

Im Focus: Pulsar with widest orbit ever detected

Discovered by high school research team

A team of highly determined high school students discovered a never-before-seen pulsar by painstakingly analyzing data from the National Science Foundation's...

Im Focus: Erosion, landslides and monsoon across the Himalaya

Scientists from Nepal, Switzerland and Germany was now able to show how erosion processes caused by the monsoon are mirrored in the sediment load of a river crossing the Himalaya.

In these days, it was again tragically demonstrated that the Himalayas are one of the most active geodynamic regions of the world. Landslides belong to the...

Im Focus: Through the galaxy by taxi - The Dream Chaser Space Utility Vehicle

A world-class prime systems integrator and electronic systems provider known for its rapid, innovative, and agile technology solutions, Sierra Nevada Corporation (SNC) is currently developing a new space transportation system called the Dream Chaser.

The ultimate aim is to construct a multi-mission-capable space utility vehicle, while accelerating the overall development process for this critical capability...

Im Focus: High-tech textiles – more than just clothes

Today, textiles are used for more than just clothes or bags – they are high tech materials for high-tech applications. High-tech textiles must fulfill a number of functions and meet many requirements. That is why the Fraunhofer Institute for Silicate Research ISC dedicated some major developing work to this most intriguing research area. The result can now be seen at Techtextil trade show in Frankfurt from 4 to 7 May. On display will be novel textile-integrated sensors, a unique multifunctional coating system for textiles and fibers, and textile processing of glass, carbon, and ceramics fibers to fiber preforms.

Thin materials and new kinds of sensors now make it possible to integrate silicone elastomer sensors in textiles. They are suitable for applications in medical...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Green Summit 2015: the summit of the essential

05.05.2015 | Event News

HHL Energy Conference on May 11/12, 2015: Students Discuss about Decentralized Energy

23.04.2015 | Event News

“Developing our cities, preserving our planet”: Nobel Laureates gather for the first time in Asia

23.04.2015 | Event News

 
Latest News

3-D models of neuronal networks reveal organizational principles of sensory cortex

06.05.2015 | Life Sciences

Molecular link found between high glucose, metabolic disease

06.05.2015 | Life Sciences

Services for innovative urban systems

06.05.2015 | Ecology, The Environment and Conservation

VideoLinks
B2B-VideoLinks
More VideoLinks >>>