The nature of dwarf cepheids. I. AD Canis Minoris.
Abstract
New uvby-beta photometry of AD CMi covering several cycles is reported. No evidence for shock wave emission is detected in either the H beta line or in the Wesselink radius solutions. Due to the large acceleration at certain phases, a Wesselink analysis requires phases at equal temperatures, as opposed to phases of equal color. This explains the previously reported failure of the Wesselink method as well as the reported evidence for shock waves. The observed ultraviolet excess during the rising branch can be fully explained by effective gravity variations. A Wesselink radius of 3 solar radii is derived. This leads to a Population I mass. No evidence for a low-mass Population II nature exists for this star. Except for the large amplitude, the star is virtually indistinguishable from a normal delta Scuti variable.-
- Publication:
-
The Astrophysical Journal
- Pub Date:
- November 1975
- DOI:
- 10.1086/153933
- Bibcode:
- 1975ApJ...201..653B
- Keywords:
-
- Cepheid Variables;
- Dwarf Stars;
- Stellar Spectrophotometry;
- Ubv Spectra;
- Electrophotometry;
- H Beta Line;
- Shock Wave Propagation;
- Ultraviolet Radiation;
- Astrophysics