Variable stars in the dwarf irregular galaxy NGC 6822: the photometric catalogue

Abstract

Deep B,V time-series photometry obtained with the ESO Very Large Telescope has been used to identify variable stars in the dwarf irregular galaxy NGC 6822. We surveyed a 6.8x6.8 arcmin area of the galaxy and detected a total number of 390 candidate variables with the optimal image subtraction technique (Alard 2000). Light curves on a magnitude scale were obtained for 262 of these variables. Differential flux light curves are available for the remaining sample. In this paper we present the photometric catalogue of calibrated light curves and time-series data, along with coordinates and classification of the candidate variables. A detailed description is provided of the procedures used to identify the variable stars and calibrate their differential flux light curves on a magnitude scale.

22 pages, 19 figures only as JPEG. Revised version with corrected eq. 5. Full text with better resolution .ps figures available upon request from the authors. Uses aa.cls (included), in press on A&A. Table 2 will only be published at the CDS, Appendix A, Tables 4,5,6 will only be available in the electronic edition of the Journal

References in corpus (9)

• A method for optimal image subtraction
• CU Comae: a new field double-mode RR Lyrae, the most metal poor discovered to date
• OGLE small amplitude red giant variables in the Galactic Bar
• Updated pulsation models for anomalous Cepheids
• RR Lyrae and short-period variable stars in the dwarf irregular galaxy NGC 6822
• The Araucaria Project. The Distance to the Local Group Galaxy NGC 6822 from Cepheid Variables discovered in a Wide-Field Imaging Survey
• Variable stars in the bar of the Large Magellanic Cloud: the photometric catalogue
• Early-type variables in the Magellanic Clouds. I. Beta Cephei stars in the LMC bar
• Variable stars in nearby galaxies. V. Search for Cepheids in Field A of NGC 6822

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