First microlensing candidate towards M31 from the Nainital Microlensing Survey

Abstract

We report our first microlensing candidate NMS-E1 towards M31 from the data accumulated during the four years of Nainital Microlensing Survey. Cousin R and I band observations of ~13'x13' field in the direction of M31 have been carried out since 1998 and data is analysed using the pixel technique proposed by the AGAPE collaboration. NMS-E1 lies in the disk of M31 at α= 0:43:33.3 and δ= +41:06:44, about 15.5 arcmin to the South-East direction of the center of M31. The degenerate Paczyński fit gives a half intensity duration of ~59 days. The photometric analysis of the candidate shows that it reached R~20.1 mag at the time of maximum brightness and the colour of the source star was estimated to be (R-I)_0 ~ 1.1 mag. The microlensing candidate is blended by red variable stars; consequently the light curves do not strictly follow the characteristic Paczyński shape and achromatic nature. However its long period monitoring and similar behaviour in R and I bands supports its microlensing nature.

no changes except typos corrected, to appear in A&A

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Cited by in corpus (18)

• Limits on the Macho Content of the Galactic Halo from the EROS-2 Survey of the Magellanic Clouds
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• The Angstrom Project: a microlensing survey of the structure and composition of the bulge of the Andromeda galaxy
• Pixel lensing: Microlensing towards M31
• Photometric, kinematic and variability study in the young open cluster NGC 1960
• A new analysis of the MEGA M31 microlensing events
• Candidate microlensing events from M31 observations with the Loiano telescope
• The possibility of detecting planets in the Andromeda Galaxy
• Monte Carlo analysis of the MEGA microlensing events towards M31
• Probing MACHOs by observation of M31 pixel lensing with the 1.5m Loiano telescope
• Nainital Microlensing Survey -- detection of short period Cepheids in the disk of M31
• A Long-term photometric variability and spectroscopic study of luminous blue variable AF And in M31
• HST Imaging of MEGA Microlensing Candidates in M31
• Long-term photometric study of a faint W UMa binary in the direction of M31
• The POINT-AGAPE Survey: Comparing Automated Searches of Microlensing Events toward M31
• Probing MACHOs Toward the Galactic Bulge
• Microlensing and Variability in the Bulge of M31