TOI-1670 b and c: An Inner Sub-Neptune with an Outer Warm Jupiter Unlikely to Have Originated from High-eccentricity Migration

0557049 - ASÚ 2023 RIV US eng J - Journal Article
Tran, Q. - Bowler, B. - Endl, M. - Kabáth, Petr - Skarka, Marek - Šubjak, Ján - Karjalainen, Marie - Karjalainen, Raine … Total 41 authors
TOI-1670 b and c: An Inner Sub-Neptune with an Outer Warm Jupiter Unlikely to Have Originated from High-eccentricity Migration.
Astronomical Journal. Roč. 163, č. 5 (2022), č. článku 225. ISSN 0004-6256. E-ISSN 1538-3881
Institutional support: RVO:67985815
Keywords : spin-orbit misalignment * chain monte-carlo * low-mass stars
OECD category: Astronomy (including astrophysics,space science)
Impact factor: 5.3, year: 2022
Method of publishing: Open access

We report the discovery of two transiting planets around the bright (V = 9.9 mag) main-sequence F7 star TOI-1670 by the Transiting Exoplanet Survey Satellite. TOI-1670 b is a sub-Neptune (R-b = 2.06(-0.15)(+0.19) R-circle plus) on a 10.9 day orbit, and TOI-1670 c is a warm Jupiter (R-c= 0.987(-0.025)(+0.025) R-Jup) on a 40.7 day orbit. Using radial velocity observations gathered with the Tull Coude Spectrograph on the Harlan J. Smith telescope and HARPS-N on the Telescopio Nazionale Galileo, we find a planet mass of M-c = 0.63(-0.08)(+0.09) M(Jup )for the outer warm Jupiter, implying a mean density of rho(c) = 0.81(-0.11)(+0.13) g cm(-3). The inner sub-Neptune is undetected in our radial velocity data (M-b < 0.13 M-Jup at the 99% confidence level). Multiplanet systems like TOI-1670 hosting an outer warm Jupiter on a nearly circular orbit (l(e) = 0.09(-0.04)(+0.05)) and one or more inner coplanar planets are more consistent with “gentle”formation mechanisms such as disk migration or in situ formation rather than high-eccentricity migration. Of the 11 known systems with a warm Jupiter and a smaller inner companion, eight (73%) are near a low-order mean-motion resonance, which can be a signature of migration. TOI-1670 joins two other systems (27% of this subsample) with period commensurabilities greater than 3, a common feature of in situ formation or halted inward migration. TOI-1670 and the handful of similar systems support a diversity of formation pathways for warm Jupiters.
Permanent Link: http://hdl.handle.net/11104/0331646