Radial velocity confirmation of a hot super-Neptune discovered by TESS with a warm Saturn–mass companion

E Knudstrup, D Gandolfi, G Nowak… - Monthly Notices of …, 2023 - academic.oup.com
E Knudstrup, D Gandolfi, G Nowak, CM Persson, E Furlan, J Livingston, E Matthews
Monthly Notices of the Royal Astronomical Society, 2023academic.oup.com
We report the discovery and confirmation of the planetary system TOI-1288. This late G
dwarf harbours two planets: TOI-1288 b and TOI-1288 c. We combine TESS space-borne
and ground-based transit photometry with HARPS-N and HIRES high-precision Doppler
measurements, which we use to constrain the masses of both planets in the system and the
radius of planet b. TOI-1288 b has a period of d, a radius of 5.24±0.09 R⊕, and a mass of
42±3 M⊕, making this planet a hot transiting super-Neptune situated right in the Neptunian …
Abstract
We report the discovery and confirmation of the planetary system TOI-1288. This late G dwarf harbours two planets: TOI-1288 b and TOI-1288 c. We combine TESS space-borne and ground-based transit photometry with HARPS-N and HIRES high-precision Doppler measurements, which we use to constrain the masses of both planets in the system and the radius of planet b. TOI-1288 b has a period of  d, a radius of 5.24 ± 0.09 R, and a mass of 42 ± 3 M, making this planet a hot transiting super-Neptune situated right in the Neptunian desert. This desert refers to a paucity of Neptune-sized planets on short period orbits. Our 2.4-yr-long Doppler monitoring of TOI-1288 revealed the presence of a Saturn–mass planet on a moderately eccentric orbit () with a minimum mass of 84 ± 7 M and a period of  d. The five sectors worth of TESS data do not cover our expected mid-transit time for TOI-1288 c, and we do not detect a transit for this planet in these sectors.
Oxford University Press