HIP 41378 observed by CHEOPS: Where is planet d?
Abstract
HIP 41378 d is a long-period planet that has only been observed to transit twice, three years apart, with K2. According to stability considerations and a partial detection of the Rossiter-McLaughlin effect, d has been determined to be the most likely orbital period. We targeted HIP 41378 d with CHEOPS at the predicted transit timing based on d, but the observations show no transit. We find that large ( hours) transit timing variations (TTVs) could explain this non-detection during the CHEOPS observation window. We also investigated the possibility of an incorrect orbital solution, which would have major implications for our knowledge of this system. If d, the periods that minimize the eccentricity would be d and d. The shortest orbital period will be tested by TESS, which will observe HIP 41378 in Sector 88 starting in January 2025. Our study shows the importance of a mission like CHEOPS, which today is the only mission able to make long observations (i.e., from space) to track the ephemeris of long-period planets possibly affected by large TTVs.
Cite
@article{arxiv.2405.20077,
title = {HIP 41378 observed by CHEOPS: Where is planet d?},
author = {S. Sulis and L. Borsato and S. Grouffal and H. P. Osborn and A. Santerne and A. Brandeker and M. N. Günther and A. Heitzmann and M. Lendl and M. Fridlund and D. Gandolfi and Y. Alibert and R. Alonso and T. Bárczy and D. Barrado Navascues and S. C. Barros and W. Baumjohann and T. Beck and W. Benz and M. Bergomi and N. Billot and A. Bonfanti and C. Broeg and A. Collier Cameron and C. Corral van Damme and A. C. M. Correia and Sz. Csizmadia and P. E. Cubillos and M. B. Davies and M. Deleuil and A. Deline and L. Delrez and O. D. S. Demangeon and B. -O. Demory and A. Derekas and B. Edwards and D. Ehrenreich and A. Erikson and A. Fortier and L. Fossati and K. Gazeas and M. Gillon and M. Güdel and Ch. Helling and S. Hoyer and K. G. Isaak and L. Kiss and J. Korth and K. W. F. Lam and J. Laskar and A. Lecavelier des Etangs and D. Magrin and P. F. L. Maxted and C. Mordasini and V. Nascimbeni and G. Olofsson and R. Ottensamer and I. Pagano and E. Pallé and G. Peter and D. Piazza and G. Piotto and D. Pollacco and D. Queloz and R. Ragazzoni and N. Rando and H. Rauer and I. Ribas and N. C. Santos and G. Scandariato and D. Ségransan and A. E. Simon and A. M. S. Smith and S. G. Sousa and M. Stalport and M. Steinberger and M. Gy. Szabó and A. Tuson and S. Udry and S. Ulmer-Moll and V. Van Grootel and J. Venturini and E. Villaver and N. A. Walton and T. G. Wilson and D. Wolter and T. Zingales},
journal= {arXiv preprint arXiv:2405.20077},
year = {2024}
}
Comments
Accepted for publication in Astronomy and Astrophysics