English

The MACHO Project LMC Variable Star Inventory. VI. The Second-overtone Mode of Cepheid Pulsation From First/Second Overtone (FO/SO) Beat Cepheids

Astrophysics 2009-10-30 v1

Abstract

MACHO Project photometry of 45 LMC FO/SO beat Cepheids which pulsate in the first and second overtone (FO and SOo, respectively) has been analysed to determine the lightcurve characteristics for the SO mode of Cepheid pulsation. We predict that singly-periodic SO Cepheids will have nearly sinusoidal lightcurves; that we will only be able to discern SO Cepheids from fundamental (F) and (FO) Cepheids for P <= 1.4 days; and that the SO distribution will overlap the short-period edge of the LMC FO Cepheid period-luminosity relation (when both are plotted as a function of photometric period). We also report the discovery of one SO Cepheid candidate, MACHO*05:03:39.6-70:04:32, with a photometric period of 0.775961 +/- 0.000019 days and an instrumental amplitude of 0.047 +/- 0.009 mag in V.

Keywords

Cite

@article{arxiv.astro-ph/9808275,
  title  = {The MACHO Project LMC Variable Star Inventory. VI. The Second-overtone Mode of Cepheid Pulsation From First/Second Overtone (FO/SO) Beat Cepheids},
  author = {The MACHO Collaboration and C. Alcock and R. A. Allsman and D. R. Alves and T. S. Axelrod and A. Becker and D. P. Bennett and K. H. Cook and K. C. Freeman and K. Griest and M. J. Lehner and S. L. Marshall and D. Minniti and B. A. Peterson and M. R. Pratt and P. J. Quinn and A. W. Rodgers and A. Rorabeck and W. Sutherland and A. Tomaney and T. Vandehei and D. L. Welch},
  journal= {arXiv preprint arXiv:astro-ph/9808275},
  year   = {2009}
}

Comments

23 pages, 7 Encapsulated PostScript figures. Accepted for publication in the Astrophysical Journal