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."

Comments

Astrophysics 101

[barakn]

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!

Re:Astrophysics 101

[barakn]

UKIRT has had a series of upgrades starting in about 1990, including several generations of IR imagers, the addition of active optics, etc.. Thus the modern version of UKIRT is not 23 years old. Nor is 23 years particularly old compared to the ~400 years that telescopic observations have been made. If you read the fine print, you'll note that it took collaborative observations by 5 different telescopes to merely confirm that brown dwarfs vary in brightness (differently at different colors). While it might confirm they have weather, it certainly does not "determine what kind of weather patterns their atmospheres have." A confirmed observation of a brown dwarf was not made until 1995 (reference).