Confirmation of One of the Coldest Known Brown Dwarfs

Дата и время публикации : 2011-10-19T19:04:57Z

Авторы публикации и институты :
K. L. Luhman
A. J. Burgasser
I. Labbe
D. Saumon
M. S. Marley
J. J. Bochanski
A. J. Monson
S. E. Persson

Ссылка на журнал-издание: Ссылка на журнал-издание не найдена
Коментарии к cтатье: Astrophysical Journal, in press, for press release see
Первичная категория: astro-ph.GA

Все категории : astro-ph.GA

Краткий обзор статьи: Using two epochs of 4.5um images from the Infrared Array Camera (IRAC) on board the Spitzer Space Telescope, we recently identified a common proper motion companion to the white dwarf WD 0806-661 that is a candidate for the coldest known brown dwarf. To verify its cool nature, we have obtained images of this object at 3.6um with IRAC, at J with HAWK-I on the Very Large Telescope, and in a filter covering the red half of J with FourStar on Magellan. WD 0806-661 B is detected by IRAC but not HAWK-I or FourStar. From these data we measure colors of [3.6]-[4.5]=2.77+/-0.16 and J-[4.5]>7.0 (SNR<3). Based on these colors and its absolute magnitudes, WD 0806-661 B is the coldest companion directly imaged outside of the solar system and is a contender for the coldest known brown dwarf with the Y dwarf WISEP J1828+2650. It is unclear which of these two objects is colder given the available data. A comparison of its absolute magnitude at 4.5um to the predictions of theoretical spectra and evolutionary models suggests that WD 0806-661 B has T=300-345 K.

Category: Physics