Astrophys. J., 655, 522-527 (2007/January-3)
On the nature of the unique Hα-emitting T dwarf 2MASS J12373919+6526148.
LIEBERT J. and BURGASSER A.J.
Abstract (from CDS):
We explore and discount the hypothesis that the strong, continual Hα-emitting T dwarf 2MASS J12373919+6526148 can be explained as a young, low-gravity, very low mass brown dwarf. The source is already known to have a marginally fainter absolute magnitude than similar T dwarfs with trigonometric parallax measurements and has a tangential velocity consistent with old disk kinematics. Applying the technique of Burgasser et al. on new near-infrared spectroscopy for this source, estimates of its Teff, logg, and metallicity ([M/H]) are obtained. 2M 1237+6526 has a Teff~800-850 K. If [M/H] is solar, logg is as high as ∼5.5 (cgs) and this source is older than 10 Gyr. We find a more plausible scenario to be a modestly subsolar metallicity ([M/H]=-0.2) and moderate logg∼5.0, implying an age older than 2 Gyr and a mass greater than 0.035 M☉. The alternative explanation of the unique emission of this source, involving an interacting, close, double degenerate system, should be investigated further. Indeed, there is some evidence of a Teff<500 K companion to 2M 1237+6526 on the basis of a possible Spitzer IRAC [3.6]-[4.5] color excess. This excess may, however, be caused by a subsolar metallicity.
stars: individual (2MASS J12373919+6526148) - Stars: Low-Mass, Brown Dwarfs - Techniques: Spectroscopic
View the reference in ADS
To bookmark this query, right click on this link: simbad:2007ApJ...655..522L and select 'bookmark this link' or equivalent in the popup menu