A full transit of v 2 Lupi d and the search for an exomoon in its Hill sphere with CHEOPS

Ehrenreich, D.; Delrez, L.; Akinsanmi, B.; Wilson, T. G.; Bonfanti, A.; Beck, M.; Benz, W.; Hoyer, S.; Queloz, D.; Alibert, Y.; Charnoz, S.; Collier Cameron, A.; Deline, A.; Hooton, M.; Lendl, M.; Olofsson, G.; Sousa, S. G.; Adibekyan, V.; Alonso, R.; Anglada, G.; ... (2023). A full transit of v 2 Lupi d and the search for an exomoon in its Hill sphere with CHEOPS. Astronomy and astrophysics, 671, A154. EDP Sciences 10.1051/0004-6361/202244790

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The planetary system around the naked-eye star v2 Lupi (HD 136352; TOI-2011) is composed of three exoplanets with masses of 4.7, 11.2, and 8.6 Earth masses (M⊕). The TESS and CHEOPS missions revealed that all three planets are transiting and have radii straddling the radius gap separating volatile-rich and volatile-poor super-earths. Only a partial transit of planet d had been covered so we re-observed an inferior conjunction of the long-period 8.6 M⊕ exoplanet v2 Lup d with the CHEOPS space telescope. We confirmed its transiting nature by covering its whole 9.1 h transit for the first time. We refined the planet transit ephemeris to P = 107.1361−0.0022+0.0019 days and Tc = 2459009.7759−0.0096+0.0101 BJDTDB, improving by ~40 times on the previously reported transit timing uncertainty. This refined ephemeris will enable further follow-up of this outstanding long-period transiting planet to search for atmospheric signatures or explore the planet’s Hill sphere in search for an exomoon. In fact, the CHEOPS observations also cover the transit of a large fraction of the planet’s Hill sphere, which is as large as the Earth’s, opening the tantalising possibility of catching transiting exomoons. We conducted a search for exomoon signals in this single-epoch light curve but found no conclusive photometric signature of additional transiting bodies larger than Mars. Yet, only a sustained follow-up of v2 Lup d transits will warrant a comprehensive search for a moon around this outstanding exoplanet.

Item Type:

Journal Article (Original Article)


08 Faculty of Science > Physics Institute > Space Research and Planetary Sciences
08 Faculty of Science > Physics Institute
10 Strategic Research Centers > Center for Space and Habitability (CSH)
08 Faculty of Science > Physics Institute > NCCR PlanetS

UniBE Contributor:

Benz, Willy, Alibert, Yann Daniel Pierre, Broeg, Christopher, Demory, Brice-Olivier Denys, Fortier, A., Heng, Kevin, Jäckel, Annette, Thomas, Nicolas


500 Science > 530 Physics
500 Science > 520 Astronomy
600 Technology > 620 Engineering
500 Science > 570 Life sciences; biology
600 Technology > 610 Medicine & health




EDP Sciences




Danielle Zemp

Date Deposited:

20 Apr 2023 07:26

Last Modified:

20 Apr 2023 07:26

Publisher DOI:






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