0568103 - ASÚ 2024 RIV FR eng J - Journal Article
Orell-Miquel, J. - Nowak, G. - Murgas, F. - Kabáth, Petr … Total 23 authors
HD 191939 revisited: New and refined planet mass determinations, and a new planet in the habitable zone.
Astronomy & Astrophysics. Roč. 669, January (2023), č. článku A40. ISSN 0004-6361. E-ISSN 1432-0746
Institutional support: RVO:67985815
Keywords : stars * planets and satellites * photometric techniques
OECD category: Astronomy (including astrophysics,space science)
Impact factor: 6.5, year: 2022
Method of publishing: Open access

We report the discovery of a new non-transiting planet in the system and a refined mass determination of HD 191939 d. The new planet, HD 191939 g, has a minimum mass of 13.5 +/- 2.0 M-circle plus and a period of about 280 days. This period places the planet within the conservative habitable zone of the host star, and near a 1:3 resonance with HD 191939 e. The compilation of 362 radial velocity measurements with a baseline of 677 days from four different high-resolution spectrographs also allowed us to refine the properties of the previously known planets, including a 4.6 sigma mass determination for planet d, for which only a 2 sigma upper limit had been set until now. We confirm the previously suspected low density of HD 191939 d, which makes it an attractive target for attempting atmospheric characterisation. Overall, the planetary system consists of three sub-Neptunes interior to a Saturn-mass and a Uranus-mass planet plus a high-mass long-period companion. This particular configuration has no counterpart in the literature and makes HD 191939 an exceptional multi-planet transiting system with an unusual planet demographic worthy of future observation.
Permanent Link: https://hdl.handle.net/11104/0341998