UVBY H-Beta Photometry of Main-Sequence Stars in M67
Abstract
uvbyHβ photometry of main-sequence stars in M67 is presented and analysed. The cluster is found to have E(b-y) = 0.023±0.004, [Fe/H] = -0.06±0.07, (V-Mv)0 = 9.61±0.04, and an age of 5.0±0.5×109yr on the system of VandenBerg (1985). In deriving the cluster parameters, it is demonstrated that the binaries tend to have higher reddening, that the late F and early G stars require inclusion of a luminosity correction in the metallicity calibration, and that a strong temperature dependence exists in the δMv-δc0 relation, with the slope reaching f = 17 for the early G stars. The cm diagram above the main-sequence gap is dominated by binaries, while a paucity appears to exist below it. The turnoff shows clear evidence of a blueward hook. No evidence is found for an intrinsic spread in color on the main sequence below the gap.
- Publication:
-
The Astronomical Journal
- Pub Date:
- March 1987
- DOI:
- 10.1086/114345
- Bibcode:
- 1987AJ.....93..634N
- Keywords:
-
- Astronomical Photometry;
- Main Sequence Stars;
- Star Clusters;
- Ubv Spectra;
- Binary Stars;
- Color-Magnitude Diagram;
- G Stars;
- Interstellar Extinction;
- Late Stars;
- Metallicity;
- Stellar Luminosity;
- Astrophysics;
- CLUSTERS: OPEN