AAVSO: American Association of Variable Star Observers

Maintaining the Ephemeris of 20 CoRoT Planets: Transit Minimum Times and Potential Transit Timing Variations

Volume 48 number 2 (2020)

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Hans J. Deeg
Instituto de Astrofísica de Canarias, C. Vía Láctea S/N, E-38205 La Laguna, Tenerife, Spain, and Universidad de La Laguna, Dept. de Astrofísica, E-38206 La Laguna, Tenerife, Spain; address correspondence to hdeeg@iac.es
Peter Klagyivik
Instituto de Astrofísica de Canarias, C. Vía Láctea S/N, E-38205 La Laguna, Tenerife, Spain, Universidad de La Laguna, Dept. de Astrofísica, E-38206 La Laguna, Tenerife, Spain, and Institute of Planetary Research, German Aerospace Center, Rutherfordstrasse 2, D-12489 Berlin, Germany
James D. Armstrong
University of Hawai’i Institute for Astronomy, 34 Ohia Ku Street, Pukalani, HI 96768
David Nespral
Instituto de Astrofísica de Canarias, C. Vía Láctea S/N, E-38205 La Laguna, Tenerife, Spain, and Universidad de La Laguna, Dept. de Astrofísica, E-38206 La Laguna, Tenerife, Spain
Lev Tal-Or
Department of Physics, Ariel University, Ariel 40700, Israel
Roi Alonso
Instituto de Astrofísica de Canarias, C. Vía Láctea S/N, E-38205 La Laguna, Tenerife, Spain, and Universidad de La Laguna, Dept. de Astrofísica, E-38206 La Laguna, Tenerife, Spain
Richelle Cabatic
Dartmouth College, Thayer School of Engineering, 14 Engineering Drive, Hanover, NH 03755
Cameron Chaffey
Department of Physics, University of California, Davis, CA 95616
Bartek Gauza
Centre for Astrophysics Research, School of Physics, Astronomy and Mathematics, University of Hertfordshire, College Lane, Hatfield AL10 9AB, United Kingdom
Sergio Hoyer
Aix Marseille Université, CNRS, CNES, LAM, Marseille, France
Christopher J. Lindsay
Yale University Department of Astronomy, 52 Hillhouse Avenue, New Haven, CT 06511
Paulo Miles-Páez
European Southern Observatory, Garching, Germany
Patricio Rojo
Department of Astronomy, Universidad de Chile
Brandon Tingley
Bøggildsvej 14, 8530 Hjortshøj, Denmark

Abstract

We present 33 transit minimum times of 20 transiting planets discovered by the CoRoT mission, which have been obtained from ground-based observations since the mission’s end in 2012, with the objective to maintain the ephemeris of these planets and to identify potential transit time variations. Twelve of the observed planets are in the CoRoT fields near the galactic center and the remaining eight planets are in the fields near the anticenter. We detect indications for significant transit timing variations in the cases of CoRoT 3b, 11b, 13b, 27b. For two more planets (CoRoT 18b and 20b) we conclude that timing offsets in early follow-up observations led to ephemerides in discovery publications that are inconsistent with timings from follow-up observations in later epochs. In the case of CoRoT-20b, this might be due to the influence from a further non-transiting planet. We also note that a significant majority (23 of 33) of our reported minimum times have negative O–C values, albeit most of them are within the expected uncertainty of the ephemeris.