NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Some constraints on the color-magnitude diagram of giants in the galactic spheroidThe color-magnitude diagram of giants in the Galactic spheroid is shown to be important in determining the number-color histogram of stars brighter than B = 19 mag. This result is demonstrated by comparing a standard Galaxy model with observations of 391 stars in a field in the direction of Aquarius (l = 36.5 deg, b = -51.1 deg). More than 80 percent of the spheroid stars and 40 percent of all stars in this magnitude range and direction are predicted to be giants. At most, a few percent of the spheroid stars in the current sample can lie on the main sequence bluer than the turn-off onto the giant branch near B - V approximately 0.4. The available observations suggest that the blue tip of the horizontal branch of the spheroid must be sparsely populated about a factor of 10 less than would be expected if the color-magnitude diagram of the spheroid were the same as diagrams for any of the globular clusters M3, M13, or M92. The total dispersion in colors (measurement errors and intrinsic dispersion) has a standard deviation in B - V color that is less than 0.2 mag.
Document ID
19830065773
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Bahcall, J. N.
(Institute for Advanced Study Princeton, NJ, United States)
Soneira, R. M.
(Institute for Advanced Study Princeton, NJ, United States)
Morton, D. C.
(Anglo-Australian Observatory Epping, New South Wales, Australia)
Tritton, K. P.
(Edinburgh Royal Observatory, Edinburgh, United Kingdom)
Date Acquired
August 11, 2013
Publication Date
September 15, 1983
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 272
ISSN: 0004-637X
Subject Category
Astrophysics
Accession Number
83A46991
Funding Number(s)
CONTRACT_GRANT: NSF PHY-79-19884
CONTRACT_GRANT: NAS8-32902
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available