The differential blanketing of the main-sequence and near-main-sequence M67 stars relative to the Hyades and Coma.
The blanketing of main-sequence stars in the Hyades, Coma, and M67, and of F subgiants in M67 is compared on the basis of red photometry. The required reddening corrections are derived by several techniques that are insensitive or probably insensitive to blanketing. The mean reddening values obtained are E(B-V) of approximately 0.016 for the Hyades, 0.006 for Coma, and 0.053 for M67. These reddening values are shown to imply that there is measurable reddening well inside 100 pc, that Crawford's (1975) A- and F-star relations must be slightly revised, that significant numbers of relatively nearby field A stars are slightly reddened, that the North Galactic Pole stars of Hilditch et al. (1976) are reddened by 0.01 to 0.03 in B-V, and that Hyades-field F-star b-y comparisons must be revised. It is found from the reddening-corrected photometry that: (1) the differential Hyades-M67 blocking is greater in absolute value for early G late F stars; (2) effects of evolution on the F IV stars in M67 are clearly discernible in the UV and marginally so in B-V; and (3) the F stars on and very near the M67 main sequence have approximately the Coma blocking and considerably less than the Hyades blocking, which indicates that the zero-age metallicity of M67 is solar-normal.
The Astrophysical Journal Supplement Series
- Pub Date:
- January 1978
- Main Sequence Stars;
- Spectral Energy Distribution;
- Star Clusters;
- F Stars;
- Interstellar Extinction;
- Stellar Structure;
- Ubv Spectra;
- Main-Sequence Stars:Open Clusters