A full transit of nu.02 Lup d

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 Earth mass exoplanet nu.02 Lup d with the CHEOPS space telescope.

We confirmed its transiting nature by covering its whole 9.1h transit for the first time. We refined the planet transit ephemeris to P=107.1361^+0.0019^_-0.0022_ days and T_c_=2459009.7759^+0.0101^_-0.0096_ BJD_TDB, 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.