93 research outputs found
TOI-150: A transiting hot Jupiter in the TESS southern CVZ
We report the detection of a hot Jupiter ($M_{p}=1.75_{-0.17}^{+0.14}\
M_{J}R_{p}=1.38\pm0.04\ R_{J}\log
g=4.152^{+0.030}_{-0.043}\beta=-79.59^{\circ}$). We confirm the
planetary nature of the candidate TOI-150.01 using radial velocity observations
from the APOGEE-2 South spectrograph and the Carnegie Planet Finder
Spectrograph, ground-based photometric observations from the robotic
Three-hundred MilliMeter Telescope at Las Campanas Observatory, and Gaia
distance estimates. Large-scale spectroscopic surveys, such as APOGEE/APOGEE-2,
now have sufficient radial velocity precision to directly confirm the signature
of giant exoplanets, making such data sets valuable tools in the TESS era.
Continual monitoring of TOI-150 by TESS can reveal additional planets and
subsequent observations can provide insights into planetary system
architectures involving a hot Jupiter around a star about halfway through its
main-sequence life.Comment: 13 pages, 3 figures, 2 tables, accepted to ApJ
Searching for GEMS: TOI-6383Ab, a Giant Planet Transiting an M3-dwarf Star in a Binary System
We report on the discovery of a transiting giant planet around the 3500 K M3-dwarf star TOI-6383A located 172 pc from Earth. It was detected by the Transiting Exoplanet Survey Satellite and confirmed by a combination of ground-based follow-up photometry and precise radial velocity measurements. This planet has an orbital period of ∼1.791 days, a mass of 1.040 ± 0.094MJ, and a radius of 1.008+0.036-0.033 RJ, resulting in a mean bulk density of 1.26+0.18-0.17 g cm−3. TOI-6383A has an M dwarf companion star, TOI-6383B, which has a stellar effective temperature of Teff ∼ 3100 K and a projected orbital separation of 3126 au. TOI-6383A is a low-mass dwarf star hosting a giant planet and is an intriguing object for planetary evolution studies due to its high planet-to-star mass ratio. This discovery is part of the Searching for Giant Exoplanets around M-dwarf Stars (GEMS) Survey, intending to provide robust and accurate estimates of the occurrence of GEMS and the statistics on their physical and orbital parameters. This paper presents an interesting addition to the small number of confirmed GEMS, particularly notable since its formation necessitates massive, dust-rich protoplanetary discs and high accretion efficiency (>10%)
The Fourteenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the extended Baryon Oscillation Spectroscopic Survey and from the second phase of the Apache Point Observatory Galactic Evolution Experiment
The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has been in
operation since July 2014. This paper describes the second data release from
this phase, and the fourteenth from SDSS overall (making this, Data Release
Fourteen or DR14). This release makes public data taken by SDSS-IV in its first
two years of operation (July 2014-2016). Like all previous SDSS releases, DR14
is cumulative, including the most recent reductions and calibrations of all
data taken by SDSS since the first phase began operations in 2000. New in DR14
is the first public release of data from the extended Baryon Oscillation
Spectroscopic Survey (eBOSS); the first data from the second phase of the
Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE-2),
including stellar parameter estimates from an innovative data driven machine
learning algorithm known as "The Cannon"; and almost twice as many data cubes
from the Mapping Nearby Galaxies at APO (MaNGA) survey as were in the previous
release (N = 2812 in total). This paper describes the location and format of
the publicly available data from SDSS-IV surveys. We provide references to the
important technical papers describing how these data have been taken (both
targeting and observation details) and processed for scientific use. The SDSS
website (www.sdss.org) has been updated for this release, and provides links to
data downloads, as well as tutorials and examples of data use. SDSS-IV is
planning to continue to collect astronomical data until 2020, and will be
followed by SDSS-V.Comment: SDSS-IV collaboration alphabetical author data release paper. DR14
happened on 31st July 2017. 19 pages, 5 figures. Accepted by ApJS on 28th Nov
2017 (this is the "post-print" and "post-proofs" version; minor corrections
only from v1, and most of errors found in proofs corrected
Kepler-730: A hot Jupiter system with a close-in, transiting, Earth-sized planet
Kepler-730 is a planetary system hosting a statistically validated hot
Jupiter in a 6.49-day orbit and an additional transiting candidate in a
2.85-day orbit. We use spectroscopic radial velocities from the APOGEE-2N
instrument, Robo-AO contrast curves, and Gaia distance estimates to
statistically validate the planetary nature of the additional Earth-sized
candidate. We perform astrophysical false positive probability calculations for
the candidate using the available Kepler data and bolster the statistical
validation by using radial velocity data to exclude a family of possible binary
star solutions. Using a radius estimate for the primary star derived from
stellar models, we compute radii of and
() for Kepler-730b and
Kepler-730c, respectively. Kepler-730 is only the second compact system hosting
a hot Jupiter with an inner, transiting planet.Comment: 13 pages, 2 figures, 3 tables, published in ApJ
A Green Bank Telescope search for narrowband technosignatures between 1.1-1.9 GHz during 12 Kepler planetary transits
A growing avenue for determining the prevalence of life beyond Earth is to
search for "technosignatures" from extraterrestrial intelligences/agents.
Technosignatures require significant energy to be visible across interstellar
space and thus intentional signals might be concentrated in frequency, in time,
or in space, to be found in mutually obvious places. Therefore, it could be
advantageous to search for technosignatures in parts of parameter space that
are mutually-derivable to an observer on Earth and a distant transmitter. In
this work, we used the L-band (1.1-1.9 GHz) receiver on the Robert C. Byrd
Green Bank Telescope (GBT) to perform the first technosignature search
pre-synchronized with exoplanet transits, covering 12 Kepler systems. We used
the Breakthrough Listen turboSETI pipeline to flag narrowband hits (3 Hz)
using a maximum drift rate of 614.4 Hz/s and a signal-to-noise threshold
of 5 - the pipeline returned apparently-localized
features. Visual inspection by a team of citizen scientists ruled out 99.6% of
them. Further analysis found 2 signals-of-interest that warrant follow-up, but
no technosignatures. If the signals-of-interest are not re-detected in future
work, it will imply that the 12 targets in the search are not producing
transit-aligned signals from 1.1-1.9 GHz with transmitter powers 60 times
that of the former Arecibo radar. This search debuts a range of innovative
technosignature techniques: citizen science vetting of potential
signals-of-interest, a sensitivity-aware search out to extremely high drift
rates, a more flexible method of analyzing on-off cadences, and an extremely
low signal-to-noise threshold.Comment: 18 pages, 11 figure
Following the TraCS of exoplanets with Pan-Planets: Wendelstein-1b and Wendelstein-2b
Hot Jupiters seem to get rarer with decreasing stellar mass. The goal of the
Pan-Planets transit survey was the detection of such planets and a statistical
characterization of their frequency. Here, we announce the discovery and
validation of two planets found in that survey, Wendelstein-1b and
Wendelstein-2b, which are two short-period hot Jupiters that orbit late K host
stars. We validated them both by the traditional method of radial velocity
measurements with the HIgh Resolution Echelle Spectrometer (HIRES) and the
Habitable-zone Planet Finder (HPF) instruments and then by their Transit Color
Signature (TraCS). We observed the targets in the wavelength range of Angstr\"om and performed a simultaneous multiband transit fit and
additionally determined their thermal emission via secondary eclipse
observations. Wendelstein-1b is a hot Jupiter with a radius of
and mass of ,
orbiting a K7V dwarf star at a period of d, and has an estimated surface
temperature of about K. Wendelstein-2b is a hot Jupiter with
a radius of and a mass of
, orbiting a K6V dwarf star at a period of
d, and has an estimated surface temperature of about
K. With this, we demonstrate that multiband photometry is
an effective way of validating transiting exoplanets, in particular for fainter
targets since radial velocity (RV) follow-up becomes more and more costly for
those targets.Comment: 14 pages, 12 figures. Accepted for publication in A&
Characterization of low-mass companions to objects of interest observed with APOGEE-N
We report the characterization of 28 low-mass
() companions
to objects of interest (KOIs), eight of which were previously
designated confirmed planets. These objects were detected as transiting
companions to Sun-like stars (G and F dwarfs) by the mission
and are confirmed as single-lined spectroscopic binaries in the current work
using the northern multiplexed Apache Point Observatory Galactic Evolution
Experiment near-infrared spectrograph (APOGEE-N) as part of the third and
fourth Sloan Digital Sky Surveys. We have observed hundreds of KOIs using
APOGEE-N and collected a total of 43,175 spectra with a median of 19 visits and
a median baseline of years per target. We jointly model the
photometry and APOGEE-N radial velocities to derive
fundamental parameters for this subset of 28 transiting companions. The radii
for most of these low-mass companions are over-inflated (by ) when
compared to theoretical models. Tidally locked M dwarfs on short period orbits
show the largest amount of inflation, but inflation is also evident for
companions that are well separated from the host star. We demonstrate that
APOGEE-N data provides reliable radial velocities when compared to precise
high-resolution spectrographs that enable detailed characterization of
individual systems and the inference of orbital elements for faint ()
KOIs. The data from the entire APOGEE-KOI program is public and presents an
opportunity to characterize an extensive subset of the binary population
observed by .Comment: 98 pages (include 56 for the figure sets), 10 tables, 7 figures, 2
figure sets, accepted for publication in ApJ
Kepler-503b: An Object at the Hydrogen Burning Mass Limit Orbiting a Subgiant Star
Using spectroscopic radial velocities with the APOGEE instrument and Gaia
distance estimates, we demonstrate that Kepler-503b, currently considered a
validated Kepler planet, is in fact a brown-dwarf/low-mass star in a nearly
circular 7.2-day orbit around a subgiant star. Using a mass estimate for the
primary star derived from stellar models, we derive a companion mass and radius
of () and
(),
respectively. Assuming the system is coeval, the evolutionary state of the
primary indicates the age is Gyr. Kepler-503b sits right at the
hydrogen burning mass limit, straddling the boundary between brown dwarfs and
very low-mass stars. More precise radial velocities and secondary eclipse
spectroscopy with James Webb Space Telescope will provide improved measurements
of the physical parameters and age of this important system to better constrain
and understand the physics of these objects and their spectra. This system
emphasizes the value of radial velocity observations to distinguish a genuine
planet from astrophysical false positives, and is the first result from the
SDSS-IV monitoring of Kepler planet candidates with the multi-object APOGEE
instrument.Comment: Accepted for publication in ApJL, 12 pages, 3 figures, 2 table
Searching for Giant Exoplanets around M-dwarf Stars (GEMS) I: Survey Motivation
Recent discoveries of transiting giant exoplanets around M-dwarf stars
(GEMS), aided by the all-sky coverage of TESS, are starting to stretch theories
of planet formation through the core-accretion scenario. Recent upper limits on
their occurrence suggest that they decrease with lower stellar masses, with
fewer GEMS around lower-mass stars compared to solar-type. In this paper, we
discuss existing GEMS both through confirmed planets, as well as protoplanetary
disk observations, and a combination of tests to reconcile these with
theoretical predictions. We then introduce the \textit{Searching for GEMS}
survey, where we utilize multi-dimensional nonparameteric statistics to
simulate hypothetical survey scenarios to predict the required sample size of
transiting GEMS with mass measurements to robustly compare their bulk-density
with canonical hot-Jupiters orbiting FGK stars. Our Monte-Carlo simulations
predict that a robust comparison requires about 40 transiting GEMS (compared to
the existing sample of 15) with 5- mass measurements.
Furthermore, we discuss the limitations of existing occurrence estimates for
GEMS, and provide a brief description of our planned systematic search to
improve the occurrence rate estimates for GEMS.Comment: 16 pages + references, including 7 figures. Accepted in AAS Journal
Searching for Giant Exoplanets around M-dwarf Stars (GEMS) I: Survey Motivation
Recent discoveries of transiting giant exoplanets around M-dwarf stars (GEMS), aided by the all-sky coverage of TESS, are starting to stretch theories of planet formation through the core-accretion scenario. Recent upper limits on their occurrence suggest that they decrease with lower stellar masses, with fewer GEMS around lower-mass stars compared to solar-type. In this paper, we discuss existing GEMS both through confirmed planets, as well as protoplanetary disk observations, and a combination of tests to reconcile these with theoretical predictions. We then introduce the Searching for GEMS survey, where we utilize multidimensional nonparameteric statistics to simulate hypothetical survey scenarios to predict the required sample size of transiting GEMS with mass measurements to robustly compare their bulk-density with canonical hot Jupiters orbiting FGK stars. Our Monte Carlo simulations predict that a robust comparison requires about 40 transiting GEMS (compared to the existing sample of ∼15) with 5σ mass measurements. Furthermore, we discuss the limitations of existing occurrence estimates for GEMS and provide a brief description of our planned systematic search to improve the occurrence rate estimates for GEMS
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