Astron. Astrophys. 324, 133-136 (1997)

The galactic double-mode Cepheids

II. Properties of the generalized phase differences

E. Poretti ¹ and I. Pardo <sup>2

1</sup> Osservatorio Astronomico di Brera, Via Bianchi 46, I-22055 Merate, Italy (poretti@merate.mi.astro.it)
² Università di Milano, I-20100 Milano, Italy

Received 28 November 1996 / Accepted 3 February 1997

Abstract

By considering the least-squares fits of the double-mode Cepheid light curves discussed in Paper I we defined their properties by their Fourier parameters and generalized phase differences . When plotting the latter quantities as a function of the order, the second order terms are confined in the region just below 3 /2; the third order terms have , the fourth order ones cluster around 2 (or 0), the fifth order ones seem to have /2. The mean values are also regularly spaced. The progression of the values as function of period was investigated and the signature of a possible resonance near 6.0 d was found.

Key words: methods: data analysis stars: oscillations Cepheids Galaxy: stellar content

Send offprint requests to: E. Poretti

© European Southern Observatory (ESO) 1997

Online publication: May 26, 1998

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