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Exoplanet HAT-P-20 b Transit

ParamountME II
QSI 532 ccd camera binned 2x2 (1"/pix)
Lodestar OAG
Rc filter
HAT-P-20 b is a Jupiter sized planet orbiting a host star of Mag v 11.3. This is a result I'm pleased with considering the night was not particularly clear with seeing of fwhm 3" at best. Also, problems I had had with the mount and auto guider were resolved enabling me to keep the target star centred on the same 2-3 pixels for nearly 4 hours. A requirement for some of the Pro/Am projects I have become involved with.
HAT-P-20 b host star has a mag v 11.3 with mass and radius relative to the Sun of 0.756 and 0.694 respectively. Close to the host star there is a 12.5 mag star that makes photometry difficult.
AstroImagJ was used for the for the photometry and transit modelling for which the only variables fixed were a/R at 11.23. and the u1 and u2 limb darkening coefficients.
My Results Rj 0.89, Inc 86.9 Transit duration 112m 33sec Depth of transit 0.01745
Accepted values Rj 0.867 +/- 0.033, Inc 86.8 +/- 0.2 Duration 110m:52sec +/- 1m 9sec. Depth of Transit 0.01649
(http://exoplanets.org/detail/HAT-P-20_b)
With regard to any Transit Time Variations (TTV) the transit minima was 2m:27s early, which is in keeping with similar values on the EDT site and does not support any TTV changes. Note also that changing parameters only altered this value by ~1minute either way.
The drop in the total C count resulting in exposure changes from 90-60-90 sec..