Accuracy of Absolute Magnitudes Derived from Widths of H and K Emission Components.
Abstract
Measures of the dths of the bright reversals in H and K in the sun and in the yellow giants of the Hyades are used to establish a calibration of absolute visual magnitude as a function of emission-line width. For giant and subgiant stars the probable error of a single measurement is j 0.26 mag., and the probable error due to intrinsic scatter is about I 0.20 mag. The latter quantity is determined from comparison with 24 stars for which dir/ir < 6 . A comparison with 29 main-sequence stars gives larger values of both measuring error and intrinsic scatter. It is suggested that the principal source of intrinsic scatter for all stars may be rotational widening. Further comparison with H and K measures in three supergiants in h and x Persei and in the K-type component of Aurigae indicates that the calibration is valid for stars as bright as Mv -6.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- September 1959
- DOI:
- 10.1086/146742
- Bibcode:
- 1959ApJ...130..499W