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UBV photoelectric photometry of the 1H/2H double mode cepheid CO Aurigae
Author(s) -
Santangelo M. M. M.,
Cavalletti G.,
Benedetti W.
Publication year - 2007
Publication title -
astronomische nachrichten
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.394
H-Index - 63
eISSN - 1521-3994
pISSN - 0004-6337
DOI - 10.1002/asna.200610704
Subject(s) - cepheid variable , photometry (optics) , physics , light curve , astrophysics , photoelectric effect , galaxy , stars , astronomy , optics
We performed new UBV photoelectric photometry of the double mode cepheid CO Aur. A careful time series analysis, by means of various algorithms, of our light curves of CO Aur enabled us to confirm the two previously known periodicities (Antonello et al. 1986) and their ratio of about 0.800. This ratio can be explained if CO Aur is a double mode cepheid pulsating in the first and second overtone (1H/2H); only two such stars are known in our galaxy. From the analysis of present data, the high stability of the periods stated by Fuhrmann et al. (1984) is fully confirmed; there is no clear evidence of variations of other light curve parameters. Within the limits of our photoelectric data, the secondary periodicity of CO Aur has a perfectly sinusoidal shape. We also performed a time series analysis of the Tycho epoch photometry in B T and V T ; and the high stability of the first period of CO Aur is confirmed by the Tycho datasets too. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)