Astronomy and Astrophysics – Astrophysics
Scientific paper
2004-01-19
Mon.Not.Roy.Astron.Soc.351:1071-1098,2004
Astronomy and Astrophysics
Astrophysics
To appear in MNRAS. Revised version including additional discussion on color of variables. Additional data table will be avail
Scientific paper
10.1111/j.1365-2966.2004.07853.x
The POINT-AGAPE collaboration has been monitoring M31 for three seasons with the Wide Field Camera on the Isaac Newton Telescope. In each season, data are taken for one hour per night for roughly sixty nights during the six months that M31 is visible. The two fields of view straddle the central bulge, northwards and southwards. We have calculated the locations, periods and amplitudes of 35414 variable stars in M31 as a by-product of our microlensing search. The variables are classified according to their period and amplitude of variation. They are classified into population I and II Cepheids, Miras and semi-regular long-period variables. The population I Cepheids are associated with the spiral arms, while the central concentration of the Miras and long-period variables varies noticeably, the stars with brighter (and shorter) variations being much more centrally concentrated. A crucial role in the microlensing experiment is played by the asymmetry signal. It was initially assumed that the variable stars would not be a serious problem as their distributions would be symmetric. We demonstrate that this assumption is not correct. We find that differential extinction associated with the dust lanes causes the variable star distributions to be asymmetric. The size and direction of the asymmetry of the variable stars is measured as a function of period and amplitude of variation. The implications of this discovery for the successful completion of the microlensing experiments towards M31 are discussed. (Abridged)
An Jin H.
Baillon Paul
Calchi Novati Sebastiano
Carr Bernard J.
Creze Michel
No associations
LandOfFree
The POINT-AGAPE Survey I: The Variable Stars in M31 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The POINT-AGAPE Survey I: The Variable Stars in M31, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The POINT-AGAPE Survey I: The Variable Stars in M31 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-392045