New Neighbors from 2MASS: Activity and Kinematics at the Bottom of the Main Sequence
New Neighbors from 2MASS: Activity and Kinematics at the Bottom of the Main Sequence
We have combined 2MASS and POSS II data in a search for nearby ultracool (later than M6.5) dwarfs with K_s<12. Spectroscopic follow-up observations identify 53 M7 to M9.5 dwarfs and seven L dwarfs. The observed space density is 0.0045 +- 0.0008 M8-M9.5 dwarfs per cubic parsec, without accounting for biases, …