POSTED: 1:30 a.m. HST, Apr 19, 2011
LAST UPDATED: 1:35 a.m. HST, Apr 19, 2011
Astronomers using Mauna Kea telescopes have found what might be the coolest star ever — a brown dwarf with the same temperature as a cup of cappuccino.
The object, known as CFBDSIR 1458+10B, is 75 light-years from Earth and has a temperature of about 200 degrees Fahrenheit, just under water's boiling point.
"At such temperatures, we expect the brown dwarf has properties that are unique from previously known brown dwarfs and much closer to cold exoplanets, such as the presence of water clouds in its atmosphere," said Michael Liu of the University of Hawaii's Institute for Astronomy. "In fact, once we start taking images of gas-giant planets around sunlike stars in the near-future, I expect that many of them will look like (this)."
Brown dwarfs, essentially failed stars, lack the mass to trigger the nuclear reactions that make regular stars shine brightly. The newly discovered brown dwarf is the smaller member of a binary system detected by Liu and other astronomers using the W.M. Keck Observatory and the Canada-France- Hawaii Telescope. The researchers are reporting their discovery in the Astrophysical Journal.
The system was found last year, but at the time was thought to be a single object.
The binary system was detected using the Laser Guide Star Adaptive Optics system on the Keck II Telescope, which essentially cancels out much of Earth's atmospheric distortion.
The Spitzer Space Telescope has recently identified two other faint objects as possible contenders for the coolest known brown dwarfs, but their temperatures are not known as precisely.