An Orbital Solution for WASP-12 b: Updated Ephemeris and Evidence for Decay Leveraging Citizen Science Data

JAAVSO Volume 51 number 2 (2023) NASA Citizen Scientists have used Exoplanet Transit Interpretation Code (EXOTIC) to reduce 40 sets of time-series images of WASP-12 taken by privately owned telescopes and a 6-inch telescope operated by the Center for Astrophysics | Harvard & Smithsonian MicroObservatory (MOBs). Of these sets, 24 result in clean transit light curves of WASP-12 b which are included in the NASA Exoplanet Watch website. We use priors from the NASA Exoplanet Archive to calculate the ephemeris of the planet and combine it with ETD (Exoplanet Transit Database), ExoClock, and TESS (Transiting Exoplanet Survey Satellite) observations. Combining these datasets gives an updated ephemeris for the WASP-12 b system of 2454508.97923 +/- 0.000051 BJDTDB with an orbital period of 1.09141935 +/- 2.16e-08 days which can be used to inform the efficient scheduling of future space telescope observations. The orbital decay of the planet was found to be -6.89e-10 +/- 4.01e-11 days/epoch. These results show the benefits of long-term observations by amateur astronomers that citizen scientists can analyze to augment the field of Exoplanet research.