Volume 450, Number 2, May I 2006
|Page(s)||873 - 880|
|Section||Online catalogs and data|
|Published online||10 April 2006|
The Araucaria project. Bright variable stars in NGC 6822 from a wide-field imaging survey
Universidad de Concepción, Departamento de Física, Casilla 160–C, Concepción, Chile e-mail: [rmennick;soszynsk;wgieren]@astro-udec.cl; email@example.com
2 Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warsaw, Poland
Accepted: 5 January 2006
We have performed a search for variable stars in the dwarf irregular galaxy NGC 6822 using wide-field multi-epoch VI photometry down to a limiting magnitude . Apart from the Cepheid variables in this galaxy already reported in an earlier paper by Pietrzynski et al. (2004), we have found 1019 “non-periodic” variable stars, 50 periodically variable stars with periods ranging from 0.12 to 66 days and 146 probably periodic variables. Twelve of these stars are eclipsing binaries and fifteen are likely new, low-amplitude Cepheids. Interestingly, seven of these Cepheid candidates have periods longer than 100 days, have very low amplitudes (less than 0.2 mag in I), and are very red. They could be young, massive Cepheids still embedded in dusty envelopes. The other objects span a huge range in colours and represent a mixture of different types of luminous variables. Many of the variables classified as non-periodic in the present study may turn out to be periodic variables once a much longer time baseline will be available to study them. We provide the catalogue of photometric parameters and show the atlas of light curves for the new variable stars. Our present catalogue is complementary to the one of Baldacci et al. (2005) which has focussed on very short-period and fainter variables in a subfield in NGC 6822.
Key words: galaxies: stellar content / binaries: eclipsing / stars: variables: general / Cepheids / Local Group / binaries: general
© ESO, 2006
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.