The Optical gravitational lensing experiment. OGLE 7: Binary microlens or a new unusual variable?

Oct, 1994
14 pages
Published in:
  • Astrophys.J.Lett. 436 (1994) L103
e-Print:
Report number:
  • CFA-3959B

Citations per year

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Abstract: (arXiv)
We present the light curve of an unusual variable object, OGLE\#7, detected during the OGLE search for microlensing events. After one season of being in a low, normal state, the star brightened by more than 2mag with a characteristic double-maximum shape, and returned to normal brightness after 60 days. We consider possible explanations of the photometric behavior of OGLE\#7. The binary microlens model seems to be the most likely explanation -- it reproduces well the observed light curve and explains the observed colors of OGLE\#7. The characteristic time scale of the OGLE\#7 event, tEt_E, is equal to 80 days, the longest observed to date. The binary microlens model predicts that the spectrum of the star should be composite, with roughly 50\% of its light in the II-band coming from a non-lensed source.