We have identified several faint, red objects in the Hyades region which we believe are very low mass M dwarf and substellar mass "brown dwarf" members of the Hyades cluster. Proper motions for these stars, measured from Palomar Schmidt plates obtained at three different epochs, have the magnitude and direction of motion expected for membership in the cluster. Infrared JHK photometry of these stars show colors typical of late M dwarfs, but the optical colors of most of the brown dwarf candidates are anomalous. The luminosities of the faintest stars derived from the infrared photometry agree well with model predictions for 0.07 M⊙ brown dwarfs at the age of the Hyades, although the colors are bluer than models predict. We believe we have extended the Hyades mass function to objects less massive than the limit for core hydrogen burning, and that our lowest luminosity objects are true substellar "brown dwarfs" of known age and distance.
- Stars: fundamental parameters
- Stars: low mass, brown dwarfs