Back to Home

General Forum Message

Forums: Atm · Astrophotography · Blackholes · Blackholes2 · CCD · Celestron · Domes · Education
Eyepieces · Meade · Misc. · God and Science · SETI · Software · UFO · XEphem
RSS Button

Home | Discussion Forums | Misc. Topics | Post
Login

Be the first pioneers to continue the Astronomy Discussions at our new Astronomy meeting place...
The Space and Astronomy Agora
RE: RE: BROWN DWARF

Forum List | Follow Ups | Post Message | Back to Thread Topics | In Response To
Posted by Mike Wilson on May 25, 2000 13:16:52 UTC

More info on brown dwarfs.

A brown dwarf is an object that lies in the mass range between a large Jovian planet and the smallest stars. They are considered to be failed stars. The upper limit is well defined at around 80 Jupiter masses. Beyond that, the center of the object is hot enough to ignite nuclear fusion and shine to become a star. There is some debate over the lower limit, but recent discoveries put it at around 10 Jupiter masses. To look at, they would be about the same size as Jupiter but much denser. They would probably glow a dim red as the there is huge amount of heat left over from their formation.

I think the best way to distinguish between a brown dwarf and a Jovian planet is that a planet is formed from the gas and dust surrounding a newborn star, where a Brown dwarf is formed in the same way a star is: directly out of a interstellar nebula. But here is where the debate over the definition of the lower mass limit arises. For example:

It is quite possible to have a planet that weighs say, 10 Jupiter masses that is formed in a solar system and at same time have a similar object formed in an intersteller gas cloud that weighs the same. Which one is a planet and which is a brown dwarf? This is where the debate is ongoing on.

Follow Ups:

    Login to Post
    Additional Information
    Google
     
    Web www.astronomy.net
    DayNightLine
    About Astronomy Net | Advertise on Astronomy Net | Contact & Comments | Privacy Policy
    Unless otherwise specified, web site content Copyright 1994-2020 John Huggins All Rights Reserved
    Forum posts are Copyright their authors as specified in the heading above the post.
    "dbHTML," "AstroGuide," "ASTRONOMY.NET" & "VA.NET"
    are trademarks of John Huggins