New OGLE-III Planetary and Low-Luminosity Object Transits

Photometric data collected during the 2001 OGLE planetary/low-luminosity transit campaign (Udalski et al. 2002a, Acta Astron. 52, 1; astro-ph/0202320) have been reanalyzed for transits with the BLS method (Kovacs, Zucker and Mazeh 2002, astro-ph/0206099). The method turned out to be very efficient: it detected all previously found transits in the OGLE-III 2001 data and 13 additional new transits (Udalski et al. 2002b, Acta Astron. 52, 115; astro-ph/0207133)

The total number of planetary/low-luminosity object transits found in the 2001 campaign OGLE-III data is now 59.

All transits' data of the new BLS-method detections are presented in THIS TABLE.

Sizes of the stars and transiting objects were estimated by modeling the light curve with a simple transit model assuming completely dark transiting object and limb darkening of the primary star. The results for the central passage (i = 90 deg) and M_primary = 1 M_Sun can be found HERE.

New transits include a few new Jupiter size objects (R < 1.6 R_Jup). OGLE-TR-56 is especially interesting case. Model transit fit to the data indicates the size of the transiting object R_transit = 0.7 R_Jup if the passage were central (i = 90 deg), i.e. it may be less than Saturn size. The resulting size of the primary star is 0.72 R_Sun which is consistent with its color. It should be noted that the transiting object size can actually be even smaller as the data in the table scale by mass of the primary as M^{1/3}, and it is very likely that the mass of the primary in this case is smaller than 1 M_Sun. If confirmed spectroscopically to be a planet, OGLE-TR-56 would be the shortest period and one of the smallest extrasolar planet ("hot" Saturn).


PLEASE cite the following paper when using the data or referring to these OGLE results: Udalski et al. (2002), Acta Astron., 52, 115.