Variable stars in the bar of the Large Magellanic Cloud: The photometric catalogue ^*,**,***

¹ INAF - Osservatorio Astronomico di Bologna, Via Ranzani 1, 40127 Bologna, Italy e-mail: [gisella.clementini;marcella.maio;angela.bragaglia;eugenio.carretta; paolo.montegriffo]@bo.astro.it
² INAF - Centro Galileo Galilei & Telescopio Nazionale Galileo, PO Box 565, 38700 S.Cruz de La Palma, Spain e-mail: difabrizio@tng.iac.es
³ INAF - Osservatorio Astronomico di Padova, Vicolo dell'Osservatorio 5, 35122 Padova, Italy e-mail: gratton@pd.astro.it

⁴ Pontificia Universidad Católica de Chile, Departado de Astronomía y Astrofísica, Av. Vicuna Mackenna 4860, 782-0436, Macul, Santiago, Chile e-mail: mzoccali@astro.puc.cl
⁵ Princeton University Observatory, Peyton Hall, Princeton NJ 08544, USA

Received: 14 July 2004
Accepted: 27 September 2004

Abstract

The catalogue of the Johnson-Cousins and I light curves obtained for 162 variable stars (135 RR Lyrae, 4 candidate Anomalous Cepheids, 11 Classical Cepheids, 11 eclipsing binaries and 1 δ Scuti star) in two areas close to the bar of the Large Magellanic Cloud is presented along with coordinates, finding charts, periods, epochs, amplitudes, and mean quantities (intensity- and magnitude-averaged luminosities) of the variables with full coverage of the light variations. A star by star comparison is made with MACHO and OGLE II photometries based on both variable and constant stars in common, and the transformation relationships to our photometry are provided. The pulsation properties of the RR Lyrae stars in the sample are discussed in detail. Parameters of the Fourier decomposition of the light curves are derived for the fundamental mode RR Lyrae stars with complete and regular curves (29 stars). They are used to estimate metallicities, absolute magnitudes, intrinsic colours, and temperatures of the variable stars, according to Jurcsik & Kovács ([CITE], A&A, 312, 111), and Kovács & Walker ([CITE], A&A, 371, 579) method. Quantities derived from the Fourier parameters are compared with the corresponding observed quantities. In particular, the “photometric” metallicities are compared with the spectroscopic metal abundances derived by Gratton et al. ([CITE], A&A, 421, 937) from low resolution spectra obtained with FORS at the Very Large Telescope.