Hostname: page-component-77c89778f8-n9wrp Total loading time: 0 Render date: 2024-07-20T13:36:24.432Z Has data issue: false hasContentIssue false

EROS: Short Period Cepheids in the Bar of the LMC

Published online by Cambridge University Press:  12 April 2016

J.P. Beaulieu*
Affiliation:
Institut d’Atrophysique de Paris, 98 bis Boulevard Arago, 75014 PARIS, FRANCE

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

We present Fourier analysis at 490 nm for 87 Cepheid light curves in the bar of the Large Magellanic Cloud. The photometry has been obtained through the EROS project whose main purpose is the search for baryonic dark matter in the Galactic halo. The very high quality of the photometry and the good phase coverage enable us to obtain accurate Fourier decomposition of the light curves. As a consequence we confirm that the so-called s-Cepheids are overtone pulsators and represent about 30 % of our sample, whereas the Classical Cepheids are fundamental pulsators. We have identified a number of features in plots of amplitude ratios and phase differences versus period. These features are usually related to resonances between different pulsation modes. If we accept that Fourier decomposition techniques applied to light curves yield positions for the centres of resonances, then it seems that resonances occur in LMC Cepheids at the same period as in Galactic Cepheids for fundamental pulsators, whereas they appear to be at shorter periods for overtone pulsators.

Type
Part 1. The Scientific Programme
Copyright
Copyright © Astronomical Society of the Pacific 1995

References

Alcock, C., et al. 1995, AJ, in pressGoogle Scholar
Andreasen, G.K., & Petersen, J.O. 1987, A&A, 180, 127 Google Scholar
Antonello, E., & Poretti, E. 1986, A&A, 169, 149 Google Scholar
Antonello, E., Poretti, E., & Reduzzi, L. 1990, A&A, 236, 138 Google Scholar
Antonello, E. 1994, A&A, 282, 835 Google Scholar
Arnaud, M. et al. 1994a, Experimental Astron., 4, 265 Google Scholar
Arnaud, M. et al. 1994b, Experimental Astron., 4, 279 Google Scholar
Aubourg, E., et al. 1993a, The Messenger, 72, 20 Google Scholar
Aubourg, E., et al. 1993b, Nature, 365, 623 Google Scholar
Beaulieu, J.P., et al. 1995, A&A, in pressGoogle Scholar
Buchler, J.R., & Goupil, M.J. 1984, ApJ, 279, 394 Google Scholar
Buchler, J.R., & Moskalik, P. 1994, A&A, 292, 450 Google Scholar
Feast, M.W. 1984, Magellanic Cloud Cepheids. in: van den Bergh, S., de Boer, K.S. (eds) Proc. IAU Symp. 108, Structure and evolution of the Magellanic Clouds. Reidel, Dordrecht p.157 Google Scholar
Gieren, W.P., et al. 1990, AJ, 99, 1196 Google Scholar
Grison, P. 1994, A&A, 289, 404 Google Scholar
Grison, P., et al. 1995, A&AS, 109, 1 Google Scholar
Kholopov, P.N., et al. 1985, General Catalogue of Variable Stars, 4th edition, Vol. I. Nauka, Moscow Google Scholar
Klapp, J., Goupil, M.J., & Buchler, J.R. 1985, ApJ, 296, 514 Google Scholar
Paczyǹski, B., 1986, ApJ, 304, 1 Google Scholar
Moskalik, P., Buchler, J.R., & Marom, M. 1992, ApJ, 385, 685 Google Scholar
Payne-Gaposchkin, C.H. 1971, Smithson. Contr. Astrophys. No. 13 Google Scholar
Poretti, E. 1994, A&A, 285, 524 Google Scholar
Scargle, J.D. 1982, ApJ, 263, 835 Google Scholar
Simon, N.R., 1988, The Fourier decomposition technique: Interpreting the variations of pulsating stars. In: Stalio, R., Willson, L.A. (eds) Pulsation and Mass Loss in Stars. Kluwer, Dordrecht p.27 Google Scholar
Simon, N.R., & Lee, A. 1981, ApJ, 248, 291 Google Scholar
Simon, N.R. 1985, ApJ, 299, 723 Google Scholar
Stellingwerf, R.F., & Donohoe, M. 1986, ApJ, 306, 183 Google Scholar
Stellingwerf, R.F., & Donohoe, M. 1987, ApJ, 314, 252 Google Scholar