AAVSO: American Association of Variable Star Observers

25 New Light Curves and Updated Ephemeris through Analysis of Exoplanet WASP-50 b with EXOTIC

Volume 49 number 2 (2021)

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Ramy Mizrachi
Stanford Online High School, 415 Broadway Academy Hall, Floor 2, 8853, Redwood City, CA 94063; ramymizrachi@gmail.com
Dylan Ly
Stanford Online High School, 415 Broadway Academy Hall, Floor 2, 8853, Redwood City, CA 94063; wuyifighter@gmail.com
Leon Bewersdorff
Citizen Scientist, Sandkaulbach 3-5, 52062 Aachen, North Rhine-Westphalia, Germany; leon.bewersdorff@rwth-aachen.de
Kalee Tock
Stanford Online High School, 415 Broadway Academy Hall, Floor 2, 8853, Redwood City, CA 94063; kaleeg@stanford.edu

Abstract

EXOplanet Transit Interpretation Code (EXOTIC) was used to reduce 75 sets of time-series images of WASP-50 taken by the 6-inch telescope of the Center for Astrophysics | Harvard & Smithsonian MicroObservatory. Of these sets, 25 resulted in clean light curves showing the transit of WASP-50 b, 22 of which had sufficiently low uncertainty to qualify for use in an ephemeris update. We used these results to establish planetary parameters and update WASP-50 b’s mid-transit time from 2455558.61237 ± 0.0002 to 2456295.68245 ± 0.00085 (BJD_TDB) and its period from 1.9551 ± 5–06 to 1.95509584 ± 0.00000106 d. The mid-transit time uncertainty of WASP-50 b at the time of projected James Webb Telescope science operations (January 2022) is reduced by a factor of 4.0 using our new ephemeris. We also calculate the planetary size and semi-major axis of WASP-50 b to be approximately 83,200 km ± 2,230 km and 0.0294AU ± 0.0000233 AU, respectively.