Not all brown dwarfs are brown
We report observations of an unusually blue brown dwarf, a nearby object that may be among the coldest and oldest brown dwarfs known. The source, ULAS J141623.94+134836.3, was originally discovered in the UKIDSS survey independently by R. Scholz and B. Burningham et al., and early results indicated its surface could be as cool as 500 K. It could even be the first Y dwarf. Our near-infrared spectrum, obtained with the IRTF SpeX spectrograph, instead shows it to be somewhat warmer (650 K), as well as old, massive and depleted in “metals” (any element other than hydrogen and helium). ULAS J1416+1348 is also a companion to the unusually blue L dwarf SDSS J141624.08+134826.7 discovered earlier this year by several groups. This nearby brown dwarf pair has generated a lot of interest among astronomers, with five publications in six months.
This result was published in in the Astronomical Journal; it was also an IRTF science highlight.
June 2010
