2007 - Second season (1.52m Cassini telescope)



Project goal







Links to other ML teams

Data analysis pipeline

(Restricted access)

We collected
n410 exposures per field in the R band
n280 exposures per field in the I band


  We have established a fully automated pipeline for the detection and the characterisation of microlensing-like flux variations
  The selection pipeline leave us with two candidates microlensing events, that we name OAB-N1 and OAB-N2
  Updated analysis of event OAB-N2


Projected on M31, we display the boundaries of the two 1312.6 monitored fields.

The filled circle mark the position of the selected microlensing candidate events.




The microlensing candidate event OAB-N1: R and I band light curves (filled and empty symbols, respectively). The solid and the dashed lines are the best-fitting Paczyński curves with t0=4433.8 and t0=4430.6 (JD-2450000.0), respectively.


The microlensing candidate event OAB-N2: R and I band light curves (filled and empty symbols, respectively).  The solid line is the best-fitting Paczyński curve.

  • A quite short event, t1/2 = 7.1 days
  • A flux variation not too bright, ΔR = 21.1 q
  • The INT data extension appears to be flat
  • Poor value of the χ2
  • The quality of the fit is not good: several points before the bump deviate significantly from the expected shape:

    • nearby variable star?

    • sign of its intrinsic non-microlening nature?

    • some kind of eruptive variable?

  • Extremely bright, ΔR = 19.1

  • Short flux variation, t1/2 = 2.8 days

  • Located near the M31 centre

  • Completely flat INT extension

  • Cross-identification of the possible source star in

    the catalogue of Massey et al. (2006)



Editor of this page: Luigi Mancini  Last update: 27/05/2010