791 research outputs found
TOI-5126: A hot super-Neptune and warm Neptune pair discovered by and
We present the confirmation of a hot super-Neptune with an exterior Neptune
companion orbiting a bright (V = 10.1 mag) F-dwarf identified by the
(). The two
planets, observed in sectors 45, 46 and 48 of the extended
mission, are and
with d and
d orbital periods, respectively. We also obtained
precise space based photometric follow-up of the system with ESAs
() to constrain
the radius and ephemeris of TOI-5126 b. TOI 5126 b is located in the "hot
Neptune Desert" and is an ideal candidate for follow-up transmission
spectroscopy due to its high predicted equilibrium temperature ( K) implying a cloud-free atmosphere. TOI-5126 c is a warm
Neptune ( K) also suitable for follow-up. Tentative
transit timing variations (TTVs) have also been identified in analysis,
suggesting the presence of at least one additional planet, however this signal
may be caused by spot-crossing events, necessitating further precise
photometric follow-up to confirm these signals.Comment: Accepted in MNRAS, 18 pages, 14 figure
VaTEST III : validation of 8 potential super-earths from TESS data
Funding: The ULiegeâs contribution to SPECULOOS has received funding from the European Research Council under the European Unionâs Seventh Framework Programme (FP/2007-2013) (grant Agreement n⊠336480/SPECULOOS). This research is in part funded by the European Unionâs Horizon 2020 research and innovation programme (grants agreements n⊠803193/BEBOP), and from the Science and Technology Facilities Council (STFC; grant n⊠ST/S00193X/1, and ST/W000385/1).NASAâs all-sky survey mission, the Transiting Exoplanet Survey Satellite (TESS), is specifically engineered to detect exoplanets that transit bright stars. Thus far, TESS has successfully identified approximately 400 transiting exoplanets, in addition to roughly 6 000 candidate exoplanets pending confirmation. In this study, we present the results of our ongoing project, the Validation of Transiting Exoplanets using Statistical Tools (VaTEST). Our dedicated effort is focused on the confirmation and characterisation of new exoplanets through the application of statistical validation tools. Through a combination of ground-based telescope data, high-resolution imaging, and the utilisation of the statistical validation tool known as TRICERATOPS, we have successfully discovered eight potential super-Earths. These planets bear the designations: TOI-238b (1.61 +0.09â0.10 R â ), TOI-771b (1.42 +0.11â0.09 R â ), TOI-871b (1.66 +0.11â0.11 R â ), TOI-1467b (1.83 +0.16â0.15 R â ), TOI-1739b (1.69 +0.10â0.08 R â ), TOI-2068b (1.82 +0.16â0.15 R â ), TOI-4559b (1.42 +0.13â0.11 R â ), and TOI-5799b (1.62 +0.19â0.13 R â ). Among all these planets, six of them fall within the region known as âkeystone planetsâ, which makes them particularly interesting for study. Based on the location of TOI-771b and TOI-4559b below the radius valley we characterised them as likely super-Earths, though radial velocity mass measurements for these planets will provide more details about their characterisation. It is noteworthy that planets within the size range investigated herein are absent from our own solar system, making their study crucial for gaining insights into the evolutionary stages between Earth and Neptune.Peer reviewe
TESS Hunt for Young and Maturing Exoplanets (THYME) VII : Membership, rotation, and lithium in the young cluster Group-X and a new young exoplanet
The public, all-sky surveys Gaia and TESS provide the ability to identify new
young associations and determine their ages. These associations enable study of
planetary evolution by providing new opportunities to discover young
exoplanets. A young association was recently identified by Tang et al. and
F{\"u}rnkranz et al. using astrometry from Gaia (called "Group-X" by the
former). In this work, we investigate the age and membership of this
association; and we validate the exoplanet TOI 2048 b, which was identified to
transit a young, late G dwarf in Group-X using photometry from TESS. We first
identified new candidate members of Group-X using Gaia EDR3 data. To infer the
age of the association, we measured rotation periods for candidate members
using TESS data. The clear color--period sequence indicates that the
association is the same age as the Myr-old NGC 3532. We obtained
optical spectra for candidate members that show lithium absorption consistent
with this young age. Further, we serendipitously identify a new, small
association nearby Group-X, which we call MELANGE-2. Lastly, we statistically
validate TOI 2048 b, which is \rearth\ radius planet on a 13.8-day
orbit around its 300 Myr-old host star.Comment: Revised to correct error in reported planet radius (original: 2.1
Earth radii, corrected: 2.6 Earth radii) and units for planetary radius ratio
entries in Table 8. All data tables available open-access with the AJ articl
TOI-2285b: A 1.7 Earth-radius planet near the habitable zone around a nearby M dwarf
We report the discovery of TO1-2285b, a sub-Neptune-sized planet transiting a nearby (42 pc) M dwarf with a period of 27.3 d. We identified the transit signal from the Transiting Exoplanet Survey Satellite photometric data, which we confirmed with ground-based photometric observations using the multiband imagers MuSCAT2 and MuSCAT3. Combining these data with other follow-up observations including high-resolution spectroscopy with the Tillinghast Reflector Echelle Spectrograph, high-resolution imaging with the SPeckle Polarimeter, and radial velocity (RV) measurements with the InfraRed Doppler instrument, we find that the planet has a radius of 1.74 +/- 0.08 R-circle plus, a mass of <19.5 M-circle plus + (95% c.I.), and an insolation flux of 1.54 +/- 0.14 times that of the Earth. Although the planet resides just outside the habitable zone for a rocky planet, if the planet harbors an H2O layer under a hydrogen-rich atmosphere, then liquid water could exist on the surface of the H2O layer depending on the planetary mass and water mass fraction. The bright host star in the near-infrared (K-s = 9.0) makes this planet an excellent target for further RV and atmospheric observations to improve our understanding of the composition, formation, and habitability of sub-Neptune-sized planets
Two Warm Super-Earths Transiting the Nearby M Dwarf TOI-2095
We report the detection and validation of two planets orbiting TOI-2095 (TIC
235678745). The host star is a 3700K M1V dwarf with a high proper motion. The
star lies at a distance of 42 pc in a sparsely populated portion of the sky and
is bright in the infrared (K=9). With data from 24 Sectors of observation
during TESS's Cycles 2 and 4, TOI-2095 exhibits two sets of transits associated
with super-Earth-sized planets. The planets have orbital periods of 17.7 days
and 28.2 days and radii of 1.30 and 1.39 Earth radii, respectively. Archival
data, preliminary follow-up observations, and vetting analyses support the
planetary interpretation of the detected transit signals. The pair of planets
have estimated equilibrium temperatures of approximately 400 K, with stellar
insolations of 3.23 and 1.73 times that of Earth, placing them in the Venus
zone. The planets also lie in a radius regime signaling the transition between
rock-dominated and volatile-rich compositions. They are thus prime targets for
follow-up mass measurements to better understand the properties of warm,
transition radius planets. The relatively long orbital periods of these two
planets provide crucial data that can help shed light on the processes that
shape the composition of small planets orbiting M dwarfs.Comment: Submitted to AAS Journal
TOI-4010: A System of Three Large Short-Period Planets With a Massive Long-Period Companion
We report the confirmation of three exoplanets transiting TOI-4010
(TIC-352682207), a metal-rich K dwarf observed by TESS in Sectors 24, 25, 52,
and 58. We confirm these planets with HARPS-N radial velocity observations and
measure their masses with 8 - 12% precision. TOI-4010 b is a sub-Neptune ( days, , ) in the hot Neptune desert, and is one of the
few such planets with known companions. Meanwhile, TOI-4010 c ( days,
, ) and TOI-4010 d ( days, , )
are similarly-sized sub-Saturns on short-period orbits. Radial velocity
observations also reveal a super-Jupiter-mass companion called TOI-4010 e in a
long-period, eccentric orbit ( days and based on
available observations). TOI-4010 is one of the few systems with multiple
short-period sub-Saturns to be discovered so far.Comment: 26 pages, 16 figures, published in A
The TESS Grand Unified Hot Jupiter Survey. I. Ten TESS Planets
We report the discovery of ten short-period giant planets (TOI-2193A b,
TOI-2207 b, TOI-2236 b, TOI-2421 b, TOI-2567 b, TOI-2570 b, TOI-3331 b,
TOI-3540A b, TOI-3693 b, TOI-4137 b). All of the planets were identified as
planet candidates based on periodic flux dips observed by NASA's Transiting
Exoplanet Survey Satellite (TESS). The signals were confirmed to be from
transiting planets using ground-based time-series photometry, high angular
resolution imaging, and high-resolution spectroscopy coordinated with the TESS
Follow-up Observing Program. The ten newly discovered planets orbit relatively
bright F and G stars (,~ between 4800 and 6200 K).
The planets' orbital periods range from 2 to 10~days, and their masses range
from 0.2 to 2.2 Jupiter masses. TOI-2421 b is notable for being a Saturn-mass
planet and TOI-2567 b for being a ``sub-Saturn'', with masses of and Jupiter masses, respectively. In most cases, we
have little information about the orbital eccentricities. Two exceptions are
TOI-2207 b, which has an 8-day period and a detectably eccentric orbit (), and TOI-3693 b, a 9-day planet for which we can set an upper
limit of . The ten planets described here are the first new planets
resulting from an effort to use TESS data to unify and expand on the work of
previous ground-based transit surveys in order to create a large and
statistically useful sample of hot Jupiters.Comment: 44 pages, 15 tables, 21 figures; revised version submitted to A
The TESS-Keck Survey. XI. Mass Measurements for Four Transiting sub-Neptunes orbiting K dwarf TOI-1246
Multi-planet systems are valuable arenas for investigating exoplanet architectures and comparing planetary siblings. TOI-1246 is one such system, with a moderately bright K dwarf (V=11.6, K=9.9) and four transiting sub-Neptunes identified by TESS with orbital periods of 4.31 d, 5.90 d, 18.66 d, and 37.92 d. We collected 130 radial velocity observations with Keck/HIRES and TNG/HARPS-N to measure planet masses. We refit the 14 sectors of TESS photometry to refine planet radii (2.97±0.06 Râ,2.47±0.08 Râ,3.46±0.09 Râ, 3.72±0.16 Râ), and confirm the four planets. We find that TOI-1246 e is substantially more massive than the three inner planets (8.1±1.1Mâ, 8.8±1.2Mâ, 5.3±1.7Mâ, 14.8±2.3Mâ). The two outer planets, TOI-1246 d and TOI-1246 e, lie near to the 2:1 resonance (Pe/Pd=2.03) and exhibit transit timing variations. TOI-1246 is one of the brightest four-planet systems, making it amenable for continued observations. It is one of only six systems with measured masses and radii for all four transiting planets. The planet densities range from 0.70±0.24 to 3.21±0.44g/cm3, implying a range of bulk and atmospheric compositions. We also report a fifth planet candidate found in the RV data with a minimum mass of 25.6 ± 3.6 Mâ. This planet candidate is exterior to TOI-1246 e with a candidate period of 93.8 d, and we discuss the implications if it is confirmed to be planetary in nature
The TESS-Keck Survey. XI. Mass Measurements for Four Transiting Sub-Neptunes Orbiting K Dwarf TOI-1246
Multiplanet systems are valuable arenas for investigating exoplanet architectures and comparing planetary siblings. TOI-1246 is one such system, with a moderately bright K dwarf (V = 11.6, K = 9.9) and four transiting sub-Neptunes identified by TESS with orbital periods of 4.31, 5.90, 18.66, and 37.92 days. We collected 130 radial velocity observations with Keck/HIRES and TNG/HARPS-N to measure planet masses. We refit the 14 sectors of TESS photometry to refine planet radii (2.97 +/- 0.06 R (circle plus), 2.47 +/- 0.08 R (circle plus), 3.46 +/- 0.09 R (circle plus), and 3.72 +/- 0.16 R (circle plus)) and confirm the four planets. We find that TOI-1246 e is substantially more massive than the three inner planets (8.1 +/- 1.1 M (circle plus), 8.8 +/- 1.2 M (circle plus), 5.3 +/- 1.7 M (circle plus), and 14.8 +/- 2.3 M (circle plus)). The two outer planets, TOI-1246 d and TOI-1246 e, lie near to the 2:1 resonance (P (e)/P ( d ) = 2.03) and exhibit transit-timing variations. TOI-1246 is one of the brightest four-planet systems, making it amenable for continued observations. It is one of only five systems with measured masses and radii for all four transiting planets. The planet densities range from 0.70 +/- 0.24 to 3.21 +/- 0.44 g cm(-3), implying a range of bulk and atmospheric compositions. We also report a fifth planet candidate found in the RV data with a minimum mass of 25.6 +/- 3.6 M (circle plus). This planet candidate is exterior to TOI-1246 e, with a candidate period of 93.8 days, and we discuss the implications if it is confirmed to be planetary in nature
The TESS Grand Unified Hot Jupiter Survey. II. Twenty New Giant Planets
NASA's Transiting Exoplanet Survey Satellite (TESS) mission promises to
improve our understanding of hot Jupiters by providing an all-sky,
magnitude-limited sample of transiting hot Jupiters suitable for population
studies. Assembling such a sample requires confirming hundreds of planet
candidates with additional follow-up observations. Here, we present twenty hot
Jupiters that were detected using TESS data and confirmed to be planets through
photometric, spectroscopic, and imaging observations coordinated by the TESS
Follow-up Observing Program (TFOP). These twenty planets have orbital periods
shorter than 7 days and orbit relatively bright FGK stars ().
Most of the planets are comparable in mass to Jupiter, although there are four
planets with masses less than that of Saturn. TOI-3976 b, the longest period
planet in our sample ( days), may be on a moderately eccentric orbit
(), while observations of the other targets are consistent
with them being on circular orbits. We measured the projected stellar obliquity
of TOI-1937A b, a hot Jupiter on a 22.4 hour orbit with the Rossiter-McLaughlin
effect, finding the planet's orbit to be well-aligned with the stellar spin
axis (). We also investigated the possibility that
TOI-1937 is a member of the NGC 2516 open cluster, but ultimately found the
evidence for cluster membership to be ambiguous. These objects are part of a
larger effort to build a complete sample of hot Jupiters to be used for future
demographic and detailed characterization work.Comment: 67 pages, 11 tables, 13 figures, 2 figure sets. Resubmitted to ApJS
after revision
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