Faculty of Mathematics, Physics
and Informatics
Comenius University Bratislava

Exoplanets


The AGO observers attempted to observe transiting exoplanet for several times. While photometry of the exoplanet transits does not belong to our main observational program, the atmospheric and observational conditions are not ideal for our main belt asteroid photometry program, therefore our 0.60-m Cassegrain type telescope with the Ap8 CCD camera can be aimed at some of the transiting   exoplanets. In addition to the transit alone we observe the part of the lightcurve approximately an hour before and after the predicted first and last contact. Photometric data are processed in the MaxIm DL software (photometry and calibration for the flat field, dark and bias) or in the own photometric program (image calibration in IRAF, photometric processing in the software created within the dissertation thesis by Világi, 2007).

Despite the relatively large number of transiting exoplanets, our equipment allows us to observe transits with a deep magnitude drop. Currently, there is a web site of the Czech astronomical society which offers transit minima ephemerides and catalogue of the transits made by amateur and professional astronomers (Exoplanet transit database). We performed the first successful observation of transiting exoplanet in Slovakia in 2008 (Corot-Exo-2b), photometric lightcurve and resulting data and derived transiting system parameters were published (Vereš et al., 2009). Further observations of more exoplanets were directly submitted to the Exoplanet transit database, which is able to process the data online and determine the physical parameters of the system (Mandel & Agol, 2002;  Kwee, K.K.  van Woerden, 1956). These follow-up observation are important for investigation of the transit duration, the time shift of the minimum or the lightcurve changes during following transits of the same object. These changes may imply presence of the additional, so far undetected exoplanet or massive moon orbiting the exoplanet.

Kwee, K. K., van Woerden, H. 1956, Bull. of the Astr. Inst. of the Netherlands, 464, 327

Mandel, K., Agol, E. 2002, ApJ, 580, 171

Vereš, P., Budaj, J., Világi, J., Galád, A., Kornoš, L. 2009. Contrib. Astron. Obs. Skalnaté Pleso, 39, 34