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Brown Dwarf Companion to Epsilon Indi
silent lurker writes "A team of European astronomers has discovered a Brown Dwarf object (a 'failed' star) less than 12 light-years from the Sun. It is the nearest yet known. Now designated Epsilon Indi B, it is a companion
to a well-known bright star in the southern sky, Epsilon Indi (now "Epsilon Indi A"), previously thought to be single. The binary system
is one of the twenty nearest stellar systems to the Sun. ...and astronomers believe there might be as many as 12x as many brown dwarf stars as there are visible ones! Hmmmm... Lots o' juicy fodder for SF content creators, dontcha think? ...not to mention astronomers themselves. See press release from
European Southern Observatory. Another item is from
Science Daily."
Well in Elite anyway.
Ah well... Lonely life.
Mouse powered Chips, Open source Processors and Lego
Brown dwarfs are thought to form in much the same way as stars, by the gravitational collapse of clumps of cold gas and dust in dense molecular clouds. However, for reasons not yet entirely clear, some clumps end up with masses less than about 7.5% of that of our Sun, or 75 times the mass of planet Jupiter. Below that boundary, there is not enough pressure in the core to initiate nuclear hydrogen fusion, the long-lasting and stable source of power for ordinary stars like the Sun. Except for a brief early phase where some deuterium is burned, these low-mass objects simply continue to cool and fade slowly away while releasing the heat left-over from their birth.
Troll Stars, anyone?
-MT.
So how much more dark matter must we account for to get the right Omega value?
Opinions on the Twiddler2 hand-held keyboard?
Some back-of-the-envelope calculations using some crude rules-of-thumb: Stars roughly follow a mass-luminosity relationship. L / Lsun=(M / Msun)^2.3 (for M.5*Msun). An estimate for this object indicates it should be .0007 times as luminous as the sun. Actually, due to the lack of fusion, it is only .00002 times as bright.
Also, from Wien's displacement law (lamda_max*T = .290 cm K) and the object's estimated surface temperature of 1273 K, it's peak radiation occurs at a wavelength of 2280 nm, far into the infrared.
The bulk of what little light brown dwarves emit is emitted in the infrared, making them practically invisible without a very expensive (and new) telescope. This has led to speculation that an unnoticed brown dwarf (the infamous Nemesis) could be orbiting our own sun!
"I'm so moist I'm sticking to the leather." -Kermit the Frog on The Late Late Show
Brown dwarf? Good god! For those of you living in a cave, the proper ethnically-sensitive term is "Vertically-challenged African-American". How would you like someone to refer to you as "Whitey 4-eyes"? At least you guys had the sense to use the word "companion" rather than "hooker" although "escort" would also be acceptable.
Just because they don't spend their nights recompiling their Linux kernals doesn't make them any less of a person than you. Let's try to use modern terminology here, people!
GMD
watch this
IIRC, the Tellurites (big shaggy piggy folks) on Star Trek: TOS were from Epsilon Indi (or is it Indii).
I'd verify all this, but most of my Star Trek nerdophernalia is packed in a box somewhere.
You are in a maze of twisty little passages, all alike.
"It was a big mistake" said one scientist "Apparently, someone had spilled chocolate pudding on the lens of the telescope, and suddenly you have everyone claiming to see 'brown dwarves.'"
Who spilled the pudding onto the lens was not immediately evident.
Ed Wedig
Graphic design services
docbrown.net
"A team of European astronomers has discovered a Brown Dwarf object (a 'failed' star)..."
Must...not...make...Gary Coleman...or Emmanuel Lewis...joke...too...late...
Actually, Jupiter and Saturn are too small to be considered brown dwarfs. The upper mass limit for brown dwarf is about 0.08 solar masses, or about 80 Jupiter masses. The lower limit is a little squishy, but most astronomers who study brown dwarfs would not include Jupiter in the brown dwarf category. The lower limit is probably something like 10 Jupiter masses.
I object to the characterization of the star as "failed". While it may be true that it is something of an under-achiever, I would submit that Epsilon Indi B will eventually turn around and realize it's full potential.
If it could only find a one-by-four-by-nine monolith, Epsilon Indi B might well transform itself brilliantly. While Epsilon Indi B may live in a vacuum, its fate is far from predetermined, and who are you or anyone else to say otherwise?
--Jimmy has fancy plans; and pants to match.
This just in, Dr. Mortimer Snerd of Bigscope Observatory has found an earthlike planet orbiting a brown dwarf 20 lightyears from earth. Says Snerd, "The planet is identical to earth in mass, orbital period, rotation, land to sea ratio, and elemental composition. It's just $&%*$# colder than a witches tit!"
7% of the exoplanets listed at this table are greater than 10 Jupiter masses. Deuterium burning occurs at 10-12 Jupiter masses and greater, but doesn't help us categorize objects that have burned up their deuterium. 2-3 Jupiter masses might be a good dividing line, as it marks the transition from the object's radius increasing with mass to the radius actually decreasing with mass (which I won't go into as it leads to discussions of things like electron degeneracy pressure). Other definitions of planets and brown dwarfs make a distinction between the method of formation of the object, but this makes the mass much less important than the object's history, which is much harder to deduce. For instance, Jupiter was long regarded as having formed from runaway accretion starting with a small rocky core, but recent computer models suggest it (and the other gas giants) formed directly from gravitational collapse, just like a star. Also consider the 55-78 Jupiter mass object found orbiting at a distance roughly equivalent to Saturn's orbit around a sun-like star, a distance much too close for many astronomers' comfort.
"I'm so moist I'm sticking to the leather." -Kermit the Frog on The Late Late Show
actually no, if G the gravitational constant, M the sum of the mass of earth & "Snerd's Turd [he just named the brown dwarf], w is 2*pi over orbital period, and r the distance between "Witch-tit World" and Snerd's Turd, we find that:
G*M = w^2 * r^3
which shows that if we decrease M, it can be compensated for to yield same orbital period by decreasing the distance between the two bodies.
Dr. Snerd says he is folding a wire coathanger and to please report to the Observatory for your knuckle pimp-sticking