Wesselink radii for classical cepheids.
Abstract
Wesselink radii have been determined for 14 classical Cepheids (TT Aql, Aql, RT Aur, RX Aur, Cep, X Cyg, W Gem, Gem, T Mon, Y Oph, AW Per, S Sge, T Vul, and U Vul). New data were used to match the light and radial velocity curves in phase. From several hundred Wesselink solutions, sources of observational error have been analyzed, and the results are summarized in Table 1. The scatter in the period-radius relation is approximately the same as that expected from errors. The slope of the period radius relation differs from that predicted by Stobie's models. Radii found for the Cepheids in open clusters using Thompson's surface brightness color relation also have a significantly steeper slope than the Wesselink radii. The slopes of the three period-radius relations agree if several of the short-period stars in the Wesselink radii sample are assumed to be pulsating in the first overtone. Subject headings: stars: Cepheids - stars: pulsation
- Publication:
-
The Astrophysical Journal
- Pub Date:
- October 1976
- DOI:
- 10.1086/154701
- Bibcode:
- 1976ApJ...209..135E