Photometric Techniques Using Small College Research Instruments for Study of the Extrasolar Planetary Transits of HD 209458

Abstract

We present the results of a program to develop techniques that enable high-resolution photometric measurements using modest research instruments available to small colleges, and then demonstrate those techniques in a pilot photometric project.

Using a 25 cm Schmidt–Cassegrain telescope and SBIG ST7E CCD camera, we develop techniques that enabled milli-magnitude photometric resolution. The pilot project studied five transits of the recently discovered gas giant planet orbiting HD 209458. We measured a flux drop of 1.46 ± 0.17% during the transit which corresponds to a planetary diameter of 1.39 ± 0.14 R_Jup, a transit period of 2^h 48^min ± 21^min, and planet orbital inclination of 87.6 ± 1.3°. We determined the orbital period as 3.5234 ± 0.0026 days. These results agree well with other studies which used professional grade research instruments. We suggest a number of other challenging photometric research areas suitable for graduate and undergraduate investigation using equipment common to many small colleges.