Spectral Types of Suspected Metal-poor Stars in the Direction of the NGP
Abstract
(B - V) colors and Mg indices have been obtained for over 360 stars in the direction of the North Galactic Pole, to V ~ 18.5. Three dozen of the stars have Mg indices which are indicative of metal-poor stars. Twelve range in brightness from V=12 to 16, while another dozen are brighter than 18.0. To determine whether or not these stars truly are halo giants or nearby dwarfs, we want to obtain classification spectra. If proven to be giants, their faintness means most are in the pure ``halo" population, well beyond the ``thick disk". If dwarfs, they then reside mainly within the thick-disk region. In either case, their metallicities will add to the information from which the metallicity gradient is determined, the existence of which (or at least value) is open to question, as well as the velocity dispersion σ_W.
- Publication:
-
NOAO Proposal
- Pub Date:
- February 2000
- Bibcode:
- 2000noao.prop..394Y