Abstract
The relative rarity of giant planets around low-mass stars compared with solar-type stars is a key prediction from the core-accretion planet formation theory. In this paper we report on the ...discovery of four gas giant planets that transit low-mass late K and early M dwarfs. The planets HATS-74Ab (TOI 737b), HATS-75b (TOI 552b), HATS-76b (TOI 555b), and HATS-77b (TOI 730b) were all discovered from the HATSouth photometric survey and follow-up using TESS and other photometric facilities. We use the new ESPRESSO facility at the VLT to confirm systems and measure their masses. We find that these planets have masses of 1.46 ± 0.14
M
J, 0.491 ± 0.039
M
J, 2.629 ± 0.089
M
J, and
1.374
−
0.074
+
0.100
M
J, respectively, and radii of 1.032 ± 0.021
R
J, 0.884 ± 0.013
R
J, 1.079 ± 0.031
R
J, and 1.165 ± 0.021
R
J, respectively. The planets all orbit close to their host stars with orbital periods ranging from 1.7319 days to 3.0876 days. With further work, we aim to test core-accretion theory by using these and further discoveries to quantify the occurrence rate of giant planets around low-mass host stars.
ABSTRACT
We report on four new transiting hot Jupiters discovered by the WASP-South survey. WASP-178b transits a V = 9.9, A1V star with Teff = 9350 ± 150 K, the second-hottest transit host known. It ...has a highly bloated radius of 1.81 ± 0.09 RJup, in line with the known correlation between high irradiation and large size. With an estimated temperature of 2470 ± 60 K, the planet is one of the best targets for studying ultrahot Jupiters that is visible from the Southern hemisphere. The three host stars WASP-184, WASP-185, and WASP-192 are all post-main-sequence G0 stars of ages 4–8 Gyr. The larger stellar radii (1.3–1.7 M⊙) mean that the transits are relatively shallow (0.7–0.9 per cent) even though the planets have moderately inflated radii of 1.2–1.3 RJup. WASP-185b has an eccentric orbit (e = 0.24) and a relatively long orbital period of 9.4 d. A star that is 4.6 arcsec from WASP-185 and 4.4 mag fainter might be physically associated.
ABSTRACT
We report the discovery and characterization of WASP-180Ab, a hot Jupiter confirmed by the detection of its Doppler shadow and by measuring its mass using radial velocities. We find the 0.9 ... ± 0.1 MJup, 1.24 ± 0.04 RJup planet to be in a misaligned, retrograde orbit around an F7 star with Teff = 6500 K and a moderate rotation speed of vsin i⋆ = 19.9 km s−1. The host star is the primary of a V = 10.7 binary, where a secondary separated by ∼5 arcsec (∼1200 au) contributes ∼ 30 per cent of the light. WASP-180Ab therefore adds to a small sample of transiting hot Jupiters known in binary systems. A 4.6-d modulation seen in the WASP data is likely to be the rotational modulation of the companion star, WASP-180B.
Despite the thousands of planets in orbit around stars known to date, the mechanisms of planetary formation, migration, and atmospheric loss remain unresolved. In this work, we confirm the planetary ...nature of a young Saturn-size planet transiting a solar-type star every 8.03 d, TOI-1135 b. The age of the parent star is estimated to be in the interval of 125-1000 Myr based on various activity and age indicators, including its stellar rotation period of 5.13 ± 0.27 days and the intensity of photospheric lithium. We obtained follow-up photometry and spectroscopy, including precise radial velocity measurements using the CARMENES spectrograph, which together with the TESS data allowed us to fully characterise the parent star and its planet. As expected for its youth, the star is rather active and shows strong photometric and spectroscopic variability correlating with its rotation period. We modelled the stellar variability using Gaussian process regression. We measured the planetary radius at 9.02 ± 0.23 R ⊕ (0.81 ± 0.02 R Jup ) and determined a 3 σ upper limit of < 51.4 M ⊕ (< 0.16 M Jup ) on the planetary mass by adopting a circular orbit. Our results indicate that TOI-1135 b is an inflated planet less massive than Saturn or Jupiter but with a similar radius, which could be in the process of losing its atmosphere by photoevaporation. This new young planet occupies a region of the mass-radius diagram where older planets are scarse, and it could be very helpful to understanding the lower frequency of planets with sizes between Neptune and Saturn.
We present the discovery of three new transiting hot Jupiters by the WASP-South project, WASP-161 b, WASP-163 b, and WASP-170 b. Follow-up radial velocities obtained with the Euler/CORALIE ...spectrograph and transit light curves obtained with the TRAPPIST-North, TRAPPIST-South, SPECULOOS-South, NITES, and Euler telescopes have enabled us to determine the masses and radii for these transiting exoplanets. WASP-161 b completes an orbit around its V = 11.1 F6V-type host star in 5.406 days, and has a mass Mp = 2.5 0.2MJup and radius Rp = 1.14 0.06 RJup. WASP-163 b orbits around its host star (spectral type G8V and the magnitude V = 12.5) every 1.609 days, and has a mass of MP = 1.9 0.2 MJup and a radius of Rp = 1.2 0.1 RJup. WASP-170 b has a mass of 1.7 0.2 MJup and a radius of 1.14 0.09 RJup and is on a 2.344 day orbit around a G1V-type star of magnitude V = 12.8. Given their irradiations (∼109 erg s−1 cm−2) and masses, the three new planets' sizes are in good agreement with classical models of irradiated giant planets.
This paper deals with two partial order techniques for Petri nets (PN in short): persistent sets and step graphs. These techniques aim to reduce the width and the depth of the marking graphs of PN, ...respectively, while preserving their deadlocks. To achieve more reductions while preserving the deadlocks of PN, this paper revisits the definition of persistent sets and establishes some weaker practical sufficient conditions. It also proposes a combination of persistent sets with steps as a sort of Cartesian product of persistent sets. This combination provides a means of better controlling the length and the number of steps, while still preserving deadlocks.
ABSTRACT
We present the discovery of three transiting planets from the WASP survey, two hot-Jupiters: WASP-177 b (∼0.5 MJup, ∼1.6 RJup) in a 3.07-d orbit of a V = 12.6 K2 star, WASP-183 b (∼0.5 MJup, ...∼1.5 RJup) in a 4.11-d orbit of a V = 12.8 G9/K0 star; and one hot-Saturn planet WASP-181 b (∼0.3 MJup, ∼1.2 RJup) in a 4.52-d orbit of a V = 12.9 G2 star. Each planet is close to the upper bound of mass–radius space and has a scaled semimajor axis, a/R*, between 9.6 and 12.1. These lie in the transition between systems that tend to be in orbits that are well aligned with their host-star’s spin and those that show a higher dispersion.
Abstract
We report the discovery of four transiting giant planets around K dwarfs. The planets HATS-47b, HATS-48Ab, HATS-49b, and HATS-72b have masses of
,
,
, and
, respectively, and radii of
,
,
, ...and
, respectively. The planets orbit close to their host stars with orbital periods of
days,
days,
days, and
days, respectively. The hosts are main-sequence K dwarfs with masses of
,
,
, and
, and with
V
-band magnitudes of
,
,
and
. The super-Neptune HATS-72b (a.k.a. WASP-191b and TOI 294.01) was independently identified as a transiting planet candidate by the HATSouth, WASP, and
TESS
surveys, and we present a combined analysis of all of the data gathered by each of these projects (and their follow-up programs). An exceptionally precise mass is measured for HATS-72b thanks to high-precision radial velocity (RV) measurements obtained with VLT/ESPRESSO, FEROS, HARPS, and
Magellan
/PFS. We also incorporate
TESS
observations of the warm Saturn–hosting systems HATS-47 (a.k.a. TOI 1073.01), HATS-48A, and HATS-49. HATS-47 was independently identified as a candidate by the
TESS
team, while the other two systems were not previously identified from the
TESS
data. The RV orbital variations are measured for these systems using
Magellan
/PFS. HATS-48A has a resolved
neighbor in
Gaia
DR2, which is a common-proper-motion binary star companion to HATS-48A with a mass of 0.22
and a current projected physical separation of ∼1400 au.
We report the discovery of two transiting exoplanets from the WASP survey, WASP-150b and WASP-176b. WASP-150b is an eccentric (e = 0.38) hot Jupiter on a 5.6 day orbit around a V = 12.03, F8 ...main-sequence host. The host star has a mass and radius of 1.4 and 1.7 respectively. WASP-150b has a mass and radius of 8.5 and 1.1 RJ, leading to a large planetary bulk density of 6.4 J. WASP-150b is found to be ∼3 Gyr old, well below its circularization timescale, supporting the eccentric nature of the planet. WASP-176b is a hot Jupiter planet on a 3.9 day orbit around a V = 12.01, F9 sub-giant host. The host star has a mass and radius of 1.3 M and 1.9 R . WASP-176b has a mass and radius of 0.86 MJ and 1.5 RJ, respectively, leading to a planetary bulk density of 0.23 J.
ABSTRACT
SuperWASP, the Northern hemisphere WASP observatory, has been observing the skies from La Palma since 2004. In that time, more than 50 planets have been discovered with data contributions ...from SuperWASP. In the process of validating planets, many false-positive candidates have also been identified. The TESS telescope is set to begin observations of the northern sky in 2019. Similar to the WASP survey, the TESS pixel size is relatively large (13 arcsec for WASP and 21 arcsec for TESS), making it susceptible to many blended signals and false detections caused principally by grazing and blended stellar eclipsing binary systems. In order to reduce duplication of effort on targets, we present a catalogue of 1 041 Northern hemisphere SuperWASP targets that have been rejected as planetary transits through follow-up observation.
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