Issue |
A&A
Volume 450, Number 2, May I 2006
|
|
---|---|---|
Page(s) | 873 - 880 | |
Section | Online catalogs and data | |
DOI | https://doi.org/10.1051/0004-6361:20054359 | |
Published online | 10 April 2006 |
The Araucaria project. Bright variable stars in NGC 6822 from a wide-field imaging survey
1
Universidad de Concepción, Departamento de Física, Casilla 160–C, Concepción, Chile e-mail: [rmennick;soszynsk;wgieren]@astro-udec.cl; pietrzyn@hubble.cfm.udec.cl
2
Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warsaw, Poland
Received:
14
October
2005
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.