Stellar population samples at the galactic poles. III. UBVRI observations of proper motion stars near the south pole and the luminosity laws for the halo and old disk populations

Journal Article · Mon Mar 01 00:00:00 EST 1976 · Astrophys. J., Suppl. Ser.; (United States)

DOI:https://doi.org/10.1086/190366· OSTI ID:7270194

Eggen, O J

Some 1200 UBV and 650 R, I observations of 1050 stars, mostly with annual proper motion greater than 0.096'', brighter than visual magnitude 15, and within 10/sup 0/ of the south galactic pole, are presented and discussed. The M-type stars (B -- V greater than + 1.15 mag) in the sample are discussed in a current article in The Astrophysical Journal, Part I. The bluer stars indicate that the slopes of the luminosity laws for old disk and halo stars are fairly similar to M/sub v/ near +6 mag, the old-disk-population law has an inflection point near M/sub v/ = +7 mag, the halo-population law may peak near M/sub v/ = +9 mag on a broad plateau that continues to beyond +10 mag and drops to zero near +13 mag, and the upper limit for the mass density of the halo population near the Sun is near 9 x 10/sup -4/ M/sub mass/ pc/sup -3/. Many stars of particular interest in the sample are briefly discussed. These include several possible red subluminous stars, one of which may be a very close solar neighbor; some halo-population giants; and one unique flare star with an amplitude near 0.5 mag in R. (auth)

• Research Organization: Australian National Univ., Canberra
• OSTI ID: 7270194
• Journal Information: Astrophys. J., Suppl. Ser.; (United States), Vol. 30:3
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
MAIN SEQUENCE STARS
PROPER MOTION
BRIGHTNESS
GIANT STARS
LUMINOSITY
PHOTOMETRY
STATISTICS
TABLES
INFORMATION
MATHEMATICS
MOTION
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
STARS
640102* - Astrophysics & Cosmology- Stars & Quasi-Stellar
Radio & X-Ray Sources