Jc. Wilson et al., Three wide-separation L dwarf companions from the Two Micron All Sky Survey: Gliese 337C, Gliese 618.1B, and HD 89744B, ASTRONOM J, 122(4), 2001, pp. 1989-2000
We present two confirmed wide-separation L dwarf common proper-motion compa
nions to nearby stars and one candidate identified from the Two Micron All
Sky Survey. Spectral types from optical spectroscopy are L0 V, L2.5 V, and
L8 V. Near-infrared, low-resolution spectra of the companions are provided,
as well as a grid of known objects spanning M6 VET dwarfs to support spect
ral type assignment for these and future L dwarfs in the z'JHK bands. Using
published measurements, we estimate ages of the companions from physical p
roperties of the primaries. These crude ages allow us to estimate companion
masses using theoretical low-mass star and brown dwarf evolutionary models
. The new L dwarfs in this paper bring the number of known wide-binary (Del
ta greater than or equal to 100 AU) L dwarf companions of nearby stars to n
ine. One of the L dwarfs is a wide-separation companion to the F7 IV-V+extr
asolar planet system HD 89744Ab.