The Activity, Variability, and Rotation of Lower Main-Sequence Members of the Coma Star Cluster
Abstract
High-precision, differential, Stromgren b, y photometric observations of nine members of the Coma star cluster, spectral types F3 V to K0 V, were made. Four G-type stars in this sample were all variable on both seasonal and year-to-year time scales, and the single K-type star also showed hints of variability. In contrast, four F-type stars were not detectably variable on either time scale. The variable stars tended to become slightly bluer as they brightened. The low-level photometric variability of Coma stars appears to resemble closely that observed among similar stars in the Hyades cluster. We also measured rotation periods for the four G-type stars from modulation present in our photometric data. The rotation periods of these stars and similar stars in the Hyades are comparable. The fact that the Coma and Hyades clusters are essentially indistinguishable in terms of their activity, variability, and rotational characteristics presents difficulties for claims that the photometric Hyades anomaly is a consequence of stellar activity. Reprints.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 20, 1990
- Accession Number
- ADA221907
Entities
People
- Brian A. Skiff
- G. W. Lockwood
- Richard R. Radick
Organizations
- Air Force Systems Command