HIPPARCOS absolute magnitudes for metal-rich K giants and the calibration of DDO photometry
Abstract
Parallaxes for 581 bright K giants have been determined using the Hipparcos satellite. We combine the trigonometric parallaxes with ground-based photometric data to determine the K giant absolute magnitudes. For all these giants, absolute magnitude estimates can also be made using the intermediate-band photometric David Dunlop Observatory (DDO) system. We compare the DDO absolute magnitudes with the very accurate Hipparcos absolute magnitudes, finding various systematic offsets in the DDO system. These systematic effects can be corrected, and we provide a new calibration of the DDO system allowing absolute magnitude to be determined with an accuracy of 0.35 mag in the range 2>M_v>-1. The new calibration performs well when tested on K giants with DDO photometry in a selection of low-reddening open clusters with well-measured distance moduli.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- February 1998
- DOI:
- 10.1046/j.1365-8711.1998.01165.x
- arXiv:
- arXiv:astro-ph/9708061
- Bibcode:
- 1998MNRAS.294...28H
- Keywords:
-
- Hipparcos Satellite;
- Stellar Magnitude;
- K Stars;
- Giant Stars;
- Metallic Stars;
- Calibrating;
- Astronomical Photometry;
- Stellar Parallax;
- Open Clusters;
- Galactic Structure;
- Milky Way Galaxy;
- Astronomy;
- STARS: FUNDAMENTAL PARAMETERS;
- GALAXY: STRUCTURE;
- Astrophysics
- E-Print:
- Submitted to MNRAS. 7 pages, 6 figures, MNRAS style file also available at http://astro.utu.fi/~cflynn/projects4.html