CAOSP abstracts, Volume: 54, No.: 2, year: 2024

Author(s): Garai, Z.; Osborn, H.P.; Tuson, A.; Ulmer-Moll, S.; The CHEOPS Consortium
Journal: Contributions of the Astronomical Observatory Skalnaté Pleso, vol. 54, no. 2, p. 150-156.
Date: 02/2024
Title: Confirming long-period transiting exoplanets with TESS and CHEOPS. The case of HD 22946 d
Keyword(s): methods: observational, techniques: photometric, planets and satellites: fundamental parameters
Pages: 150 -- 156
DOI: https://doi.org/10.31577/caosp.2024.54.2.150
NASA ADS Abstract Service: 2024CoSka..54b.150G
Citation:
License: This work is licensed under a Creative Commons Attribution 4.0 International License

Abstract: Due to the limited observing duration of the Transiting Exoplanet Survey Satellite (TESS) primary mission, which observed the majority of the near-ecliptic sectors for only 27 days, planets on long periods produce only single transits. However, thanks to its extended mission, TESS re-observed the same fields 2 years later, and in many cases was able to re-detect a second transit. These ‘duotransit’ cases require follow-up in order to uncover the true orbital period due to the gap, which causes a set of aliases. The Characterising Exoplanet Satellite (CHEOPS) space observatory can be used to follow-up duotransit targets and to determine their true orbital periods and other characteristics. We investigated the HD 22946 planetary system with a similar aim. Based on the combined TESS and CHEOPS observations, we successfully determined the true orbital period of the planet d to be 47.42489 ± 0.00011 d, and derived precise radii of the planets in the system. Planet d, as a warm sub-Neptune, is very interesting because there are only a few similar confirmed exoplanets to date.