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

Volume 48 number 2 (2020)

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 space mission. These 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. All acquired light curves are available at the Strasbourg Astronomical Data Center (CDS).