Six-Color Photometry of Stars. X. The Stellar Magnitude and Color Index of the Sun.
Abstract
By means of a device originally designed and constructed by A. E. Whitford, the sun's light was reduced by reflections from a magnesium oxide disk and a aluminized convex mirror to approximate equality with the light of a ribbon-filament tungsten lamp, operated at a color temperature near 29600 K and at a distance of 17.4 inches from the first reflector. After photoelectric coirparison of the sun and lamp through this reducer, the photometer was transferred to the Crossley reflector, where the same I amp, at a distance of 1746 feet from the telescope and diaphragmed by a pinhole aperture, was readily compared ith a number of stars of known magnitude, color, and spectral type. The results for the sun on the International scale are: photovisual magnitude -2673 + 0.03; color index, +053 + 0.01; color class, dgl Mount Wilson or g2 V on the Yerkes system. All the photometric evidence shows that the sun is a normal dwarf star of spectral type G.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- September 1957
- DOI:
- 10.1086/146398
- Bibcode:
- 1957ApJ...126..266S