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The Problem of Hipparcos Distances to Open Clusters. II. Constraints from Nearby Field TheoryThis paper examines the discrepancy between distances to nearby open clusters as determined by parallaxes from Hipparcos compared to traditional main-sequence fitting. The biggest difference is seen for the Pleiades, and our hypothesis is that if the Hipparcos distance to the Pleiades is correct, then similar subluminous zero-age main-sequence (ZAMS) stars should exist elsewhere, including in the immediate solar neighborhood. We examine a color-magnitude diagram of very young and nearby solar-type stars and show that none of them lie below the traditional ZAMS, despite the fact that the Hipparcos Pleiades parallax would place its members 0.3 mag below that ZAMS. We also present analyses and observations of solar-type stars that do lie below the ZAMS, and we show that they are subluminous because of low metallicity and that they have the kinematics of old stars.
Document ID
19990039651
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Soderblom, David R. (Space Telescope Science Inst. Baltimore, MD United States)
King, Jeremy R. (Space Telescope Science Inst. Baltimore, MD United States)
Hanson, Robert B. (California Univ. Santa Cruz, CA United States)
Jones, Burton F. (California Univ. Santa Cruz, CA United States)
Fischer, Debra (San Francisco State Univ. CA United States)
Stauffer, John R. (Harvard-Smithsonian Center for Astrophysics Cambridge, MA United States)
Pinsonneault, Marc H. (Ohio State Univ. Columbus, OH United States)
Date Acquired
August 19, 2013
Publication Date
September 1, 1998
Publication Information
Publication: Astrophysical Journal
Volume: 504
Subject Category
Astronomy
Funding Number(s)
CONTRACT_GRANT: NAG5-4830
CONTRACT_GRANT: NAGw-4837
CONTRACT_GRANT: NSF AST-95-30632
Distribution Limits
Public
Copyright
Other