Exoplanet XO2-b
| RA | 07 48 07 |
| DEC | +50 13 33 |
| Out of transit V magnitude | 11.18 |
| Measured transit duration (mins) | 147.6± 3.5 |
| Measured transit depth (mmag) | 11±0.9 |
XO2-b is a "hot jupiter" planet orbiting a star 149±4 parsecs away in the constellation Lynx. It was dicovered in 2007 as part of the XO project. The planet has a mass of 0.57±0.06 Jupiter masses and orbits it's parent star every 2.62 days. The star is a K0V star of mass 0.98±0.02 solar masses.
This is my first exoplanet transit measurement and I am quite pleased with the result as I know that there are still several improvements that I can make to improve the precision of the photometry. Calculated photometric precision on the raw data is ±7mmag which appears close to actual data scatter. The error on the 9 point median appears to be ~4mmag which is slightly higher than I calculated that it should be.
The dominant noise factor here seems to be atmospheric scintillation and is a factor of two greater than Poisson noise. In future I will use a redder filter such as the Wratten 25A. This should increase my exposure times so decreasing the scintillation noise. I'm hoping that it will also reduce skyglow and extinction variation of signal.
Anyway, the plot of the transit may be seen below. I submitted the data to the Exoplanet Transit Database and it allocated a quality "3" (on a scale of 1-5) which I was quite pleased with for a first go. Quality "1" is what you get if you use the GTC.
My data was analysed by the Exoplanet Transit Database and the output can be found here: http://var2.astro.cz/EN/tresca/transit-detail.php?id=1292760105. If this data is used to model the system, it would look something like this:
