Featured Research

from universities, journals, and other organizations

Even 'Failed Stars' Can Form Planets

Date:
October 26, 2005
Source:
Max Planck Society
Summary:
Astronomers from German, American, and Italian research institutes have used NASA's SPITZER space telescope to discover that there is at least the beginnings of planet formation around brown dwarfs, sometimes called 'failed stars.'

Astronomers from German, American, and Italian research institutes have used NASA΄s SPITZER space telescope to discover that there is at least the beginnings of planet formation around brown dwarfs, sometimes called ‛failed stars'.

Related Articles


Thus, the process of building planets is more universal and robust than had previously been assumed (Science Express, October 20, 2005).

Brown dwarfs, like more massive normal stars, are formed when interstellar gas and dust clouds collapse. When this happens, a central, dense area builds up, embedded in a rotating disc made of gas and dust. These circumstellar discs produce infrared radiation according to their temperature.

The collapse of gas and dust clouds ends when the increasing pressure, temperature, and density in the central area causes nuclear fusion to start -- that is, the burning of hydrogen into helium. This causes the dense area to become its own star. If its mass is too small, however, for the fusion to take place, a brown dwarf is created instead. It will have no further source of energy, and will slowly radiate the compression temperature created by the collapse.

The team of astronomers investigated six young brown dwarfs from the Chamaeleon star-forming region in the direction of the south celestial pole. The objects are between one and three million years old, and their masses are between 40 and 70 times that of Jupiter. The astonomers used SPITZER to record the detailed spectrum of infrared light, from which they derived information about the size of the radiated particles and their minerological composition.

The data analysis showed that in five of the six cases they looked at, dust particles in the circumstellar disc of the ‛failed stars' stuck together and made larger clumps of olivine, a material made of silicon and crystalline structures. The discs of young normal stars are already known to contain this material. It is also found in comets -- the leftover material from the time when our own planetary system was being built. Apparently, the same growth and crystallisation processes take place in the circumstellar discs that we see in normal stars (including the Sun) at the beginning of planet formation.

Futhermore, there was evidence that the circumstellar discs flatten out in a way that one would also expect given how the dust components develop. Daniel Apai, who is doing research at the Steward Observatory in Tuscon, Arizona and is a member of the Life and Planets Astrobiology Center NASA's Astrobiology Institute, says that ‛Using SPITZER, we can investigate planet formation under all different kinds of conditions. Our observations show that the first steps of planet formation are determined to a lesser extent by details than we previously thought'. Kees Dullemond at the Max Planck Instiute for Astronomy stresses that ‛this result is important also because it narrows down theories about planet formation and thus gives us a deeper insight into the process'.

These observational results show that in the future, in projects to find extrasolar planets -- like ESA's DARWIN mission and NASA's terrestrial planet finder -- it could be worth it to look for planets in the neighborhood of brown dwarfs.

We can look at these spectra when we do a wavelength analysis on the light collected in the telescope, similar to the way a drop of water or a prisma turns sunlight into a rainbow. The bright ‛arches', which appear at different wavelengths, are the ‛fingerprints' which allow us to read the chemical features (i.e., it contains silicate), the size, and the physical condition (from amorphous to crystalline).

In the picture, the light green vertical stripes indicate the ‛fingerprints' of crystals which are made primarily of the minieral olivine, which is green, made of silicate, and appears on earth. It seems the spectra of three of the four brown dwarfs have similar components. In interstellar dust, they are unrecognisable. They are most clearly visible in the spectrum of the Hale-Bopp comet. The bigger the dust particles, the wider the ‛arches' are in their emission spectrum.

Participants in this project: Drs Daniel Apai and Ilaria Pascucci (Steward Observatory, University of Arizona, Tucson), Drs Jeroen Bouwman, Thomas Henning and Cornelis P Dullemond (Max Planck Institute for Astronomy, Heidelberg), and Dr Antonella Natta (Osservatorio Astrofisico di Arcetri, Florence).


Story Source:

The above story is based on materials provided by Max Planck Society. Note: Materials may be edited for content and length.


Cite This Page:

Max Planck Society. "Even 'Failed Stars' Can Form Planets." ScienceDaily. ScienceDaily, 26 October 2005. <www.sciencedaily.com/releases/2005/10/051026090144.htm>.
Max Planck Society. (2005, October 26). Even 'Failed Stars' Can Form Planets. ScienceDaily. Retrieved October 31, 2014 from www.sciencedaily.com/releases/2005/10/051026090144.htm
Max Planck Society. "Even 'Failed Stars' Can Form Planets." ScienceDaily. www.sciencedaily.com/releases/2005/10/051026090144.htm (accessed October 31, 2014).

Share This



More Space & Time News

Friday, October 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Antares Liftoff Explosion

Raw: Antares Liftoff Explosion

AP (Oct. 29, 2014) — Observers near Wallops Island recorded what they thought would be a routine rocket launch Tuesday night. What they recorded was a major rocket explosion shortly after lift off. (Oct 29) Video provided by AP
Powered by NewsLook.com
Raw: Russian Cargo Ship Docks at Space Station

Raw: Russian Cargo Ship Docks at Space Station

AP (Oct. 29, 2014) — Just hours after an American cargo run to the International Space Station ended in flames, a Russian supply ship has arrived at the station with a load of fresh supplies. (Oct. 29) Video provided by AP
Powered by NewsLook.com
Journalist Captures Moment of Antares Rocket Explosion

Journalist Captures Moment of Antares Rocket Explosion

Reuters - US Online Video (Oct. 29, 2014) — A space education journalist is among those who witness and record the explosion of an unmanned Antares rocket seconds after its launch. Rough Cut (no reporter narration) Video provided by Reuters
Powered by NewsLook.com
Rocket Explosion Under Investigation

Rocket Explosion Under Investigation

AP (Oct. 28, 2014) — NASA and Orbital Sciences officials say they are investigating the explosion of an unmanned commercial supply rocket bound for the International Space Station. It blew up moments after liftoff Tuesday evening over the launch site in Virginia. (Oct. 28) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins