181 research outputs found
HATS-5b: A Transiting hot-Saturn from the HATSouth Survey
We report the discovery of HATS-5b, a transiting hot-Saturn orbiting a G type
star, by the HAT-South survey. HATS-5b has a mass of Mp=0.24 Mj, radius of
Rp=0.91 Rj, and transits its host star with a period of P=4.7634d. The radius
of HATS-5b is consistent with both theoretical and empirical models. The host
star has a V band magnitude of 12.6, mass of 0.94 Msun, and radius of 0.87
Rsun. The relatively high scale height of HATS-5b, and the bright,
photometrically quiet host star, make this planet a favourable target for
future transmission spectroscopy follow-up observations. We reexamine the
correlations in radius, equilibrium temperature, and metallicity of the
close-in gas-giants, and find hot Jupiter-mass planets to exhibit the strongest
dependence between radius and equilibrium temperature. We find no significant
dependence in radius and metallicity for the close-in gas-giant population.Comment: 10 pages, submitted to A
HATS-17b: A Transiting Compact Warm Jupiter in a 16.3 Days Circular Orbit
We report the discovery of HATS-17b, the first transiting warm Jupiter of the
HATSouth network. HATS-17b transits its bright (V=12.4) G-type
(M=1.131 0.030 M,
R=1.091 R) metal-rich ([Fe/H]=+0.3 dex)
host star in a circular orbit with a period of P=16.2546 days. HATS-17b has a
very compact radius of 0.777 0.056 R given its Jupiter-like mass of
1.338 0.065 M. Up to 50% of the mass of HATS-17b may be composed of
heavy elements in order to explain its high density with current models of
planetary structure. HATS-17b is the longest period transiting planet
discovered to date by a ground-based photometric survey, and is one of the
brightest transiting warm Jupiter systems known. The brightness of HATS-17b
will allow detailed follow-up observations to characterize the orbital geometry
of the system and the atmosphere of the planet.Comment: 12 page, 8 figures, submitted to A
HATS-6b: A Warm Saturn Transiting an Early M Dwarf Star, and a Set of Empirical Relations for Characterizing K and M Dwarf Planet Hosts
We report the discovery by the HATSouth survey of HATS-6b, an extrasolar
planet transiting a V=15.2 mag, i=13.7 mag M1V star with a mass of 0.57 Msun
and a radius of 0.57 Rsun. HATS-6b has a period of P = 3.3253 d, mass of
Mp=0.32 Mjup, radius of Rp=1.00 Rjup, and zero-albedo equilibrium temperature
of Teq=712.8+-5.1 K. HATS-6 is one of the lowest mass stars known to host a
close-in gas giant planet, and its transits are among the deepest of any known
transiting planet system. We discuss the follow-up opportunities afforded by
this system, noting that despite the faintness of the host star, it is expected
to have the highest K-band S/N transmission spectrum among known gas giant
planets with Teq < 750 K. In order to characterize the star we present a new
set of empirical relations between the density, radius, mass, bolometric
magnitude, and V, J, H and K-band bolometric corrections for main sequence
stars with M < 0.80 Msun, or spectral types later than K5. These relations are
calibrated using eclipsing binary components as well as members of resolved
binary systems. We account for intrinsic scatter in the relations in a
self-consistent manner. We show that from the transit-based stellar density
alone it is possible to measure the mass and radius of a ~0.6 Msun star to ~7%
and ~2% precision, respectively. Incorporating additional information, such as
the V-K color, or an absolute magnitude, allows the precision to be improved by
up to a factor of two.Comment: 21 pages, 11 figures, 10 tables. Submitted to AJ. Data available at
http://hatsouth.org Code implementing empirical model available at
http://www.astro.princeton.edu/~jhartman/kmdwarfparam.htm
HATS-11b and HATS-12b: Two transiting Hot Jupiters orbiting sub-solar metallicity stars selected for the K2 Campaign 7
We report the discovery of two transiting extrasolar planets from the
HATSouth survey. HATS-11, a V=14.1 G0-star shows a periodic 12.9 mmag dip in
its light curve every 3.6192 days and a radial velocity variation consistent
with a Keplerian orbit. HATS-11 has a mass of 1.000 0.060 M, a
radius of 1.444 0.057 M and an effective temperature of 6060
150 K, while its companion is a 0.85 0.12 M, 1.510 0.078
R planet in a circular orbit. HATS-12 shows a periodic 5.1 mmag flux
decrease every 3.1428 days and Keplerian RV variations around a V=12.8 F-star.
HATS-12 has a mass of 1.489 0.071 M, a radius of 2.21
0.21 R, and an effective temperature of 6408 75 K. For HATS-12,
our measurements indicate that this is a 2.38 0.11 M, 1.35 0.17
R planet in a circular orbit. Both host stars show sub-solar metallicity of
-0.390 0.060 dex and -0.100 0.040 dex, respectively and are
(slightly) evolved stars. In fact, HATS-11 is amongst the most metal-poor and,
HATS-12 is amongst the most evolved stars hosting a hot Jupiter planet.
Importantly, HATS-11 and HATS-12 have been observed in long cadence by Kepler
as part of K2 campaign 7 (EPIC216414930 and EPIC218131080 respectively).Comment: 14 pages, 7 figures, 6 tables, submitted to A
HATS-15 b and HATS-16 b: Two massive planets transiting old G dwarf stars
We report the discovery of HATS-15 b and HATS-16 b, two massive transiting
extrasolar planets orbiting evolved ( Gyr) main-sequence stars. The
planet HATS-15 b, which is hosted by a G9V star ( mag), is a hot
Jupiter with mass of and radius of
, and completes its orbit in nearly 1.7 days.
HATS-16 b is a very massive hot Jupiter with mass of and radius of ; it orbits around
its G3 V parent star ( mag) in days. HATS-16 is slightly
active and shows a periodic photometric modulation, implying a rotational
period of 12 days which is unexpectedly short given its isochronal age. This
fast rotation might be the result of the tidal interaction between the star and
its planet.Comment: 16 pages, 8 figures, submitted to PAS
The Aligned Orbit of the Eccentric Proto Hot Jupiter TOI-3362b
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 the tidal reprocessing of
their orbital elements, proto-hot Jupiters 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 VLT. The observations reveal a sky-projected obliquity deg and constrain the orbital eccentricity to , making it one of the most eccentric gas giants for which the obliquity
has been measured. The large eccentricity and the striking orbit alignment of
the planet 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.Comment: ApJL 958 L20 (9 pages, 6 figures
HATS-9b and HATS-10b: Two Compact Hot Jupiters in Field 7 of the K2 Mission
We report the discovery of two transiting extrasolar planets by the HATSouth
survey. HATS-9b orbits an old (10.8 1.5 Gyr) V=13.3 G dwarf star, with a
period P = 1.9153 d. The host star has a mass of 1.03 M, radius of
1.503 R and effective temperature 5366 70 K. The planetary
companion has a mass of 0.837 M, and radius of 1.065 R yielding a mean
density of 0.85 g cm . HATS-10b orbits a V=13.1 G dwarf star, with a
period P = 3.3128 d. The host star has a mass of 1.1 M, radius of 1.11
R and effective temperature 5880 120 K. The planetary companion
has a mass of 0.53 M, and radius of 0.97 R yielding a mean density of
0.7 g cm . Both planets are compact in comparison with planets receiving
similar irradiation from their host stars, and lie in the nominal coordinates
of Field 7 of K2 but only HATS-9b falls on working silicon. Future
characterisation of HATS-9b with the exquisite photometric precision of the
Kepler telescope may provide measurements of its reflected light signature.Comment: 15 pages, 10 figures, accepted for publication in A
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