Featured Research

from universities, journals, and other organizations

Ultra-cool companion helps reveal giant planets

Date:
May 10, 2012
Source:
Royal Astronomical Society (RAS)
Summary:
Astronomers have found a brown dwarf that is more than 99% hydrogen and helium. Described as ultra-cool, it has a temperature of just 400 degrees Celsius and its discovery could be a key step forward in helping astronomers distinguish between brown dwarfs and giant planets.

This artist’s impression shows BD+01 2920B in the foreground (on the right hand side), with its host star in the background. The colour and banded atmosphere of the brown dwarf result from atmospheric gases and turbulence.
Credit: J. Pinfield, for the RoPACS network at the University of Hertfordshire.

An international team of astronomers led by David Pinfield of the University of Hertfordshire has found a brown dwarf that is more than 99% hydrogen and helium. Described as ultra-cool, it has a temperature of just 400 degrees Celsius and its discovery could be a key step forward in helping astronomers distinguish between brown dwarfs and giant planets.

The researchers publish their work in the journal Monthly Notices of the Royal Astronomical Society.

Brown dwarfs are star-like objects with insufficient mass to ignite hydrogen fusion in their cores. Over time they cool to temperatures of just a few hundred degrees. Formed like stars from the collapse of a giant molecular cloud a few hundred light years across, brown dwarfs in binary systems such as this have the same atmospheric chemistry as their host star.

In contrast, giant planets form with a more diverse chemistry. Those in our own solar system first formed as large solid cores, which then accreted gas from the disk around them. This led to a different chemistry in their outer layers. For example, when the Galileo spacecraft entered Jupiter's atmosphere in 1995, it found the proportion of heavier elements (astronomers call these 'metals') to be three times higher than in the Sun. Such differences allow astronomers to discriminate between planets and brown dwarfs and reveal their formation mechanisms.

Dr Pinfield and his team detected the brown dwarf using data from the Wide-field Infrared Explorer (WISE) satellite, the UK Infrared Telescope (UKIRT) in Hawaii and the Visible and Infrared Survey Telescope for Astronomy (VISTA) in Chile. He carried out this work as part of his European (FP7) Initial Training Network RoPACS which studies planets around cool stars.

The newly discovered object, known as BD+01 2920B, is about 35 times more massive than Jupiter. It orbits its host star at a distance of 390 billion km or about 2600 times the average distance from Earth to the Sun.

Searches for planets around other stars find many possible planets through the gravitational pull of the candidate objects on the stars they orbit as well as direct imaging using the latest (and future) optical technology on the largest telescopes. The problem is that compact brown dwarfs share many characteristics with giant planets, so astronomers struggle to confirm the nature of what they detect.

The new work has been made possible by combining data from ground- and space-based surveys, says Dr Pinfield. "Surveys from telescopes like VISTA and UKIRT and orbiting observatories like WISE are giving us an unprecedented view of 'ultra-cool' bodies in our neighbourhood."

'By finding these rare objects in orbit around nearby stars, we get a handle on the bigger picture, that we live in a galaxy where both giant planets and brown dwarfs are commonplace."


Story Source:

The above story is based on materials provided by Royal Astronomical Society (RAS). Note: Materials may be edited for content and length.


Journal Reference:

  1. D. J. Pinfield, B. Burningham, N. Lodieu, S. K. Leggett, C. G. Tinney, L. van Spaandonk, F. Marocco, R. Smart, J. Gomes, L. Smith, P. W. Lucas, A. C. Day-Jones, D. N. Murray, A. C. Katsiyannis, S. Catalan, C. Cardoso, J. R. A. Clarke, S. Folkes, M. C. Gálvez-Ortiz, D. Homeier, J. S. Jenkins, H. R. A. Jones, Z. H. Zhang. Discovery of the benchmark metal-poor T8 dwarf BD 01° 2920B. Monthly Notices of the Royal Astronomical Society, 2012; DOI: 10.1111/j.1365-2966.2012.20549.x

Cite This Page:

Royal Astronomical Society (RAS). "Ultra-cool companion helps reveal giant planets." ScienceDaily. ScienceDaily, 10 May 2012. <www.sciencedaily.com/releases/2012/05/120510100052.htm>.
Royal Astronomical Society (RAS). (2012, May 10). Ultra-cool companion helps reveal giant planets. ScienceDaily. Retrieved September 19, 2014 from www.sciencedaily.com/releases/2012/05/120510100052.htm
Royal Astronomical Society (RAS). "Ultra-cool companion helps reveal giant planets." ScienceDaily. www.sciencedaily.com/releases/2012/05/120510100052.htm (accessed September 19, 2014).

Share This



More Space & Time News

Friday, September 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

MIT BioSuit A New Take On Traditional Spacesuits

MIT BioSuit A New Take On Traditional Spacesuits

Newsy (Sep. 19, 2014) — The MIT BioSuit could be an alternative to big, bulky traditional spacesuits, but the concept needs some work. Video provided by Newsy
Powered by NewsLook.com
Boeing, SpaceX to Send Astronauts to Space Station

Boeing, SpaceX to Send Astronauts to Space Station

AFP (Sep. 17, 2014) — NASA selected Boeing and SpaceX on Tuesday to build America's next spacecraft to carry astronauts to the International Space Station (ISS) by 2017, opening the way to a new chapter in human spaceflight. Duration: 01:13 Video provided by AFP
Powered by NewsLook.com
East Coast Treated To Rare Meteor Sighting

East Coast Treated To Rare Meteor Sighting

Newsy (Sep. 16, 2014) — Numerous residents along the East Coast reported seeing a bright meteor flash through the sky Sunday night. Video provided by Newsy
Powered by NewsLook.com
Space Race Pits Bezos Vs Musk

Space Race Pits Bezos Vs Musk

Reuters - Business Video Online (Sep. 16, 2014) — Amazon CEO Jeff Bezos' startup will team up with Boeing and Lockheed to develop rocket engines as Elon Musk races to have his rockets certified. Fred Katayama reports. Video provided by Reuters
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:
from the past week

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