Astronomy Blog

Share |

Brown Dwarfs May Help Us Better Understand the Giant Planets

May 21, 2012; 8:25 AM ET

An international team of astronomers has found a brown dwarf that is made up of about 99 percent hydrogen and helium. Described as ultra-cool, its temperature is just 400 degrees Celsius and its discovery could be a key step forward in helping astronomers tell the difference between brown dwarfs and giant planets.

Brown dwarfs are starlike objects with not enough mass to ignite hydrogen fusion in their cores. Over time they cool to temperatures of just a few hundred degrees Celsius. 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 (such as Jupiter and Saturn) 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.

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 2,600 times the average distance from the 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.

You can leave your comments, as well as be part of a community where discussions on any astronomy subject, such as light pollution, when you join AccuWeather's Astronomy Facebook fanpage by clicking here.

We are now well over 3,400 likes on Facebook. Please tell your friends about this Facebook page and blog and have them weigh in on some exciting issues. We encourage open discussion and will never criticize any idea, and no negative conversation will be allowed.

The views expressed are those of the author and not necessarily those of AccuWeather, Inc. or AccuWeather.com

Comments

Comments left here should adhere to the AccuWeather.com Community Guidelines. Profanity, personal attacks, and spam will not be tolerated.

More Astronomy Weather Blog

  • Weekend astronomy viewing guide

    July 22, 2016; 4:11 PM ET

    Summer nights are the perfect time to be outdoors. Here are a few ideas for your night sky viewing this weekend. If clouds block your view, chances are you will have a cool lightning show instead!

  • Updated July Fourth Holiday weekend astronomy guide

    July 2, 2016; 4:30 PM ET

    There is a lot to see in the night sky this July Fourth holiday weekend. With the new moon soon, the Milky Way will be visible. Also, see the planets shimmer, search for the highest clouds on Earth and perhaps catch a glimpse of the aurora or a stray meteor. Sky viewing conditions are detailed for each night through Independence Day.

  • July Fourth Holiday Weekend Astronomy Guide

    July 1, 2016; 4:18 PM ET

    There is a lot to see in the night sky this July Fourth holiday weekend. See the planets shimmer, search for the highest clouds on Earth and perhaps catch a glimpse of the Aurora. Sky viewing conditions are detailed for each night through Independence Day.

  • June Bootids meteor shower

    June 24, 2016; 3:07 PM ET

    The fickle June Bootids meteor shower is only a few days away. It will peak Sunday night, but the level of activity is unknown.

About This Blog

Astronomy Blog
The AccuWeather.com astronomy blog, by Dave Samuhel, discusses stargazing, including how weather will affect viewing conditions of astronomical phenomenon.