Abstract The K-type star TOI-2525 has an estimated mass of M = 0.849 − 0.033 + 0.024 M ⊙ and radius of R = 0.785 − 0.007 + 0.007 R ⊙ observed by the TESS mission in 22 sectors (within sectors 1 and ...39). The TESS light curves yield significant transit events of two companions, which show strong transit timing variations (TTVs) with a semiamplitude of ∼6 hr. We performed TTV dynamical and photodynamical light-curve analysis of the TESS data combined with radial velocity measurements from FEROS and PFS, and we confirmed the planetary nature of these companions. The TOI-2525 system consists of a transiting pair of planets comparable to Neptune and Jupiter with estimated dynamical masses of m b = 0.088 − 0.004 + 0.005 and m c = 0.709 − 0.033 + 0.034 M Jup , radii of r b = 0.88 − 0.02 + 0.02 and r c = 0.98 − 0.02 + 0.02 R Jup , and orbital periods of P b = 23.288 − 0.002 + 0.001 and P c = 49.260 − 0.001 + 0.001 days for the inner and outer planet, respectively. The period ratio is close to the 2:1 period commensurability, but the dynamical simulations of the system suggest that it is outside the mean-motion resonance (MMR) dynamical configuration. Object TOI-2525 b is among the lowest-density Neptune-mass planets known to date, with an estimated median density of ρ b = 0.174 − 0.015 + 0.016 g cm −3 . The TOI-2525 system is very similar to the other K dwarf systems discovered by TESS, TOI-2202 and TOI-216, which are composed of almost identical K dwarf primaries and two warm giant planets near the 2:1 MMR.
Abstract
High-eccentricity tidal migration predicts the existence of highly eccentric proto hot Jupiters on the “tidal circularization track,” meaning that they might eventually become hot Jupiters, ...but that their migratory journey remains incomplete. Having experienced moderate amounts of tidal evolution of their orbital elements, proto hot Jupiter systems can be powerful test beds for the underlying mechanisms of eccentricity growth. Notably, they may be used for discriminating between variants of high-eccentricity migration, each predicting a distinct evolution of misalignment between the star and the planet’s orbit. We constrain the spin–orbit misalignment of the proto hot Jupiter TOI-3362b with high-precision radial-velocity observations using ESPRESSO at Very Large Telescope. The observations reveal a sky-projected obliquity
λ
=
1.2
−
2.7
+
2.8
° and constrain the orbital eccentricity to
e
= 0.720 ± 0.016, making it one of the most eccentric gas giants for which the obliquity has been measured. Although the large eccentricity and the striking orbit alignment of the planet are puzzling, we suggest that ongoing coplanar high-eccentricity migration driven by a distant companion is a possible explanation for the system's architecture. This distant companion would need to reside beyond 5 au at 95% confidence to be compatible with the available radial-velocity observations.
Abstract
The geometries of near-resonant planetary systems offer a relatively pristine window into the initial conditions of exoplanet systems. Given that near-resonant systems have likely ...experienced minimal dynamical disruptions, the spin–orbit orientations of these systems inform the typical outcomes of quiescent planet formation, as well as the primordial stellar obliquity distribution. However, few measurements have been made to constrain the spin–orbit orientations of near-resonant systems. We present a Rossiter–McLaughlin measurement of the near-resonant warm Jupiter TOI-2202 b, obtained using the Carnegie Planet Finder Spectrograph on the 6.5 m Magellan Clay Telescope. This is the eighth result from the Stellar Obliquities in Long-period Exoplanet Systems survey. We derive a sky-projected 2D spin–orbit angle
λ
=
26
−
15
+
12
°
and a 3D spin–orbit angle
ψ
=
31
−
11
+
13
°
, finding that TOI-2202 b—the most massive near-resonant exoplanet with a 3D spin–orbit constraint to date—likely deviates from exact alignment with the host star’s equator. Incorporating the full census of spin–orbit measurements for near-resonant systems, we demonstrate that the current set of near-resonant systems with period ratios
P
2
/
P
1
≲ 4 is generally consistent with a quiescent formation pathway, with some room for low-level (≲20°) protoplanetary disk misalignments or post-disk-dispersal spin–orbit excitation. Our result constitutes the first population-wide analysis of spin–orbit geometries for near-resonant planetary systems.
Abstract We report the discovery and characterization of three giant exoplanets orbiting solar-analog stars, detected by the TESS space mission and confirmed through ground-based photometry and ...radial velocity measurements taken at La Silla observatory with FEROS. TOI-2373 b is a warm Jupiter orbiting its host star every ∼13.3 days, and is one of the most massive known exoplanet with a precisely determined mass and radius around a star similar to the Sun, with an estimated mass of m p = 9.3 − 0.2 + 0.2 M jup and a radius of r p = 0.93 − 0.2 + 0.2 R jup . With a mean density of ρ = 14.4 − 1.0 + 0.9 g cm − 3 , TOI-2373 b is among the densest planets discovered so far. TOI-2416 b orbits its host star on a moderately eccentric orbit with a period of ∼8.3 days and an eccentricity of e = 0.32 − 0.02 + 0.02 . TOI-2416 b is more massive than Jupiter with m p = 3.0 − 0.09 + 0.10 M jup , however is significantly smaller with a radius of r p = 0.88 − 0.02 + 0.02 , R jup , leading to a high mean density of ρ = 5.4 − 0.3 + 0.3 g cm − 3 . TOI-2524 b is a warm Jupiter near the hot Jupiter transition region, orbiting its star every ∼7.2 days on a circular orbit. It is less massive than Jupiter with a mass of m p = 0.64 − 0.04 + 0.04 M jup , and is consistent with an inflated radius of r p = 1.00 − 0.03 + 0.02 R jup , leading to a low mean density of ρ = 0.79 − 0.08 + 0.08 g cm − 3 . The newly discovered exoplanets TOI-2373 b, TOI-2416 b, and TOI-2524 b have estimated equilibrium temperatures of 860 − 10 + 10 K, 1080 − 10 + 10 K, and 1100 − 20 + 20 K, respectively, placing them in the sparsely populated transition zone between hot and warm Jupiters.
Abstract
We report the discovery and orbital characterization of three new transiting warm giant planets. These systems were initially identified as presenting single-transit events in the light ...curves generated from the full-frame images of the Transiting Exoplanet Survey Satellite. Follow-up radial velocity measurements and additional light curves were used to determine the orbital periods and confirm the planetary nature of the candidates. The planets orbit slightly metal-rich late F- and early G-type stars. We find that TOI 4406b has a mass of
M
P
= 0.30 ± 0.04
M
J
, a radius of
R
P
= 1.00 ± 0.02
R
J
, and a low-eccentricity orbit (
e
= 0.15 ± 0.05) with a period of
P
= 30.08364 ±0.00005 days. TOI 2338b has a mass of
M
P
= 5.98 ± 0.20
M
J
, a radius of
R
P
= 1.00 ± 0.01
R
J
, and a highly eccentric orbit (
e
= 0.676 ± 0.002) with a period of
P
= 22.65398 ± 0.00002 days. Finally, TOI 2589b has a mass of
M
P
= 3.50 ± 0.10
M
J
, a radius of
R
P
= 1.08 ± 0.03
R
J
, and an eccentric orbit (
e
= 0.522 ± 0.006) with a period of
P
= 61.6277 ± 0.0002 days. TOI 4406b and TOI 2338b are enriched in metals compared to their host stars, while the structure of TOI 2589b is consistent with having similar metal enrichment to its host star.
We report on the confirmation and follow-up characterization of two long-period transiting substellar companions on low-eccentricity orbits around TIC 4672985 and TOI-2529, whose transit events were ...detected by the TESS space mission. Ground-based photometric and spectroscopic follow-up from different facilities, confirmed the substellar nature of TIC 4672985
b
, a massive gas giant in the transition between the super-Jupiters and brown dwarfs mass regime. From the joint analysis we derived the following orbital parameters:
P
= 69.0480
−0.0005
+0.0004
d,
M
p
= 12.74
−1.01
+1.01
M
j
,
R
p
= 1.026
−0.067
+0.065
R
j
and
e
= 0.018
−0.004
+0.004
. In addition, the RV time series revealed a significant trend at the ~350 m s
−1
yr
−1
level, which is indicative of the presence of a massive outer companion in the system. TIC 4672985
b
is a unique example of a transiting substellar companion with a mass above the deuterium-burning limit, located beyond 0.1 AU and in a nearly circular orbit. These planetary properties are difficult to reproduce from canonical planet formation and evolution models. For TOI-2529
b
, we obtained the following orbital parameters:
P
= 64.5949
−0.0003
+0.0003
d,
M
p
= 2.340
−0.195
+0.197
M
j
,
R
p
= 1.030
−0.050
+0.050
R
j
and
e
= 0.021
−0.015
+0.024
, making this object a new example of a growing population of transiting warm giant planets.
