Variable stars towards the bulge of M31: the AGAPE catalogue

R. Ansari (1) , M. Auriere (2) , P. Baillon (3) , A. Bouquet (4) , G. Coupinot (2) , Ch. Coutures (5) , C. Ghesquiere (4) , Y. Giraud-Heraud (4) , D. Gillieron (2) , P. Gondolo , J. Hecquet (2) , J. Kaplan (4) , A. Kim (4) , Y. Le Du (4) , A.L. Melchior (6) , M. Moniez (1) , J.P. Picat (2) , G. Soucail (2)

1 LAL - Laboratoire de l'Accélérateur Linéaire
2 LATT - Laboratoire d'Astrophysique de l'Observatoire Midi-Pyrénées
3 CERN - European Organization for Nuclear Research
4 PCC (UMR 7553) - Physique Corpusculaire et Cosmologie
5 DAPNIA - Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée
6 LERMA - Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique

We present the AGAPE astrometric and photometric catalogue of 1579 variable stars in a 14'x10' field centred on M31. This work is the first survey devoted to variable stars in the bulge of M31. The R magnitudes of the objects and the B-R colours suggest that our sample is dominated by red long-period variable stars (LPV), with a possible overlap with Cepheid-like type II stars. Twelve nova candidates are identified. Correlations with other catalogues suggest that 2 novae could be recurrent novae and provide possible optical counterparts for 2 supersoft X-ray sources candidates observed with Chandra.

Mots clés: galaxies: individual: M 31; cosmology: dark matter; stars: variables: general; stars: novae; cataclysmic variables; stars: variables: Cepheids; X-rays: stars

Domaines: Cosmologie et astrophysique extra-galactique [astro-ph.CO]; Astrophysique [astro-ph]

R. Ansari, M. Auriere, P. Baillon, A. Bouquet, G. Coupinot, et al.. Variable stars towards the bulge of M31: the AGAPE catalogue. Astronomy and Astrophysics - A&A, 2004, 421, pp.509-518. ⟨10.1051/0004-6361:20035659⟩. ⟨in2p3-00022262⟩