Observing transiting exoplanets with the MicroObservatory: 43 new transit light curves of the hot Jupiter HAT-P-32b

TL;DR

This study demonstrates that small robotic telescopes like MicroObservatory can effectively monitor transiting exoplanets, refine their orbital parameters, and support future space missions by providing precise transit timing data over multiple years.

Contribution

It presents 43 new transit light curves of HAT-P-32b, updates the exoplanet's ephemeris, and shows the utility of small telescopes in exoplanet and stellar variability studies.

Findings

Achieved 3-minute RMS in transit timing predictions.

Refined orbital period to 2.15000815 days.

Improved mid-transit time predictions for JWST and ARIEL missions.

Abstract

Observations of 43 complete transits of the hot Jupiter exoplanet HAT-P-32b using the MicroObservatory 0.15-m robotic telescope network covering a period of 7 years are presented. Compared with the most recent ephemeris for the system, the precision of the mid-transit times yielded a root-mean-square value from the predicted model of 3.0 min. The estimated system parameters based on EXOFAST modelling are broadly consistent with those of the default parameter values listed in the NASA Exoplanet Archive. An updated orbital period of 2.15000815 +/- 0.00000013 d and ephemeris of 2458881.71392 +/- 0.00027 BJDTDB is consistent with recent studies of the system using larger telescopes. Using this updated ephemeris, the predicted mid-transit time for a notional observation of HAT-P-32b by the NASA JWST mission in mid-2021 is improved by 1.4 min compared with the discovery ephemeris and is ~8 times more precise. Likewise, the mid-transit time for an observation by the ESA ARIEL mission in 2020 is improved by 1.7 min. Thus, observations of transiting exoplanets by MicroObservatory and other users of small telescopes can contribute to the maintenance of the ephemerides of targets for future space-based telescope missions. We also note that one of the HAT-P-32 field stars is a {\delta} Scuti pulsating variable and that characterization using the same observations as this study further demonstrates the utility of MicroObservatory for the observation of stellar variability, whilst simultaneously observing transiting exoplanets for ephemeris maintenance.