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Precise Dynamical Masses of ɛ Indi Ba and Bb: Evidence of Slowed Cooling at the L/T Transition
Dupuy, Trent J.; Brandt, Timothy D.; Li, Yiting +3 more
We report individual dynamical masses of 66.92 ± 0.36 M Jup and 53.25 ± 0.29 M Jup for the binary brown dwarfs ɛ Indi Ba and Bb, measured from long-term (≈10 yr) relative orbit monitoring and absolute astrometry monitoring data on the Very Large Telescope (VLT). Relative astrometry with NACO fully constrains the Keplerian orb…
Towards a Comprehensive View of Accretion, Inner Disks, and Extinction in Classical T Tauri Stars: An ODYSSEUS Study of the Orion OB1b Association
Herczeg, Gregory J.; France, Kevin; Ábrahám, Péter +21 more
The coevolution of T Tauri stars and their surrounding protoplanetary disks dictates the timescales of planet formation. In this paper, we present magnetospheric accretion and inner disk wall model fits to near-UV (NUV) to near-IR (NIR) spectra of nine classical T Tauri stars in Orion OB1b as part of the Outflows and Disks around Young Stars: Syne…
Joint Constraints on Exoplanetary Orbits from Gaia DR3 and Doppler Data
Winn, Joshua N.
The third Gaia data release includes a catalog of exoplanets and exoplanet candidates identified via the star's astrometric motion. This paper reports on tests for consistency between the Gaia two-body orbital solutions and precise Doppler velocities for stars currently amenable to such a comparison. For BD-17 0063, HD 81040, and HD 132406, the Ga…
On Spectroscopic Phase-curve Retrievals: H2 Dissociation and Thermal Inversion in the Atmosphere of the Ultrahot Jupiter WASP-103 b
Changeat, Quentin
This work presents a reanalysis of the spectroscopic phase-curve observations of the ultrahot Jupiter WASP-103 b obtained by the Hubble Space Telescope (HST) and the Spitzer Telescope. Traditional 1D and unified 1.5D spectral retrieval techniques are employed, allowing to map the thermal structure and the abundances of trace gases in this planet a…
A Transiting, Temperate Mini-Neptune Orbiting the M Dwarf TOI-1759 Unveiled by TESS
Trifonov, Trifon; Stock, Stephan; Henning, Thomas +66 more
We report the discovery and characterization of TOI-1759 b, a temperate (400 K) sub-Neptune-sized exoplanet orbiting the M dwarf TOI-1759 (TIC 408636441). TOI-1759 b was observed by TESS to transit in Sectors 16, 17, and 24, with only one transit observed per sector, creating an ambiguity regarding the orbital period of the planet candidate. Groun…
A Census of the Low Accretors. I. The Catalog
Calvet, Nuria; Briceño, César; Hernández, Jesús +2 more
Observations have shown that the disk frequency and the fraction of accreting pre-main-sequence stars decrease with the age of the population and that some stars appear to have disks while their accretion has stopped. Still, it is unclear how disk-bearing stars stop their accretion. To provide insight into the last stages of accretion in low-mass …
Kepler and the Behemoth: Three Mini-Neptunes in a 40 Million Year Old Association
Bouma, L. G.; Bieryla, A.; Latham, D. W. +8 more
Stellar positions and velocities from Gaia are yielding a new view of open cluster dispersal. Here we present an analysis of a group of stars spanning Cepheus (l = 100°) to Hercules (l = 40°), hereafter the Cep-Her complex. The group includes four Kepler objects of interest: Kepler-1643 b (R p = 2.32 ± 0.13 R ⊕, P = 5.3 days)…
Lyα Escape from Low-mass, Compact, High-redshift Galaxies
Reddy, Naveen A.; Shivaei, Irene; Dey, Arjun +5 more
We investigate the effects of stellar populations and sizes on Lyα escape in 27 spectroscopically confirmed and 35 photometric Lyα emitters (LAEs) at z ≈ 2.65 in seven fields of the Boötes region of the NOAO Deep Wide-Field Survey. We use deep HST/WFC3 imaging to supplement ground-based observations and infer key galaxy properties. Compared to typ…
Scaling K2. V. Statistical Validation of 60 New Exoplanets From K2 Campaigns 2-18
Barclay, Thomas; Bieryla, Allyson; Latham, David W. +39 more
The NASA K2 mission, salvaged from the hardware failures of the Kepler telescope, has continued Kepler's planet-hunting success. It has revealed nearly 500 transiting planets around the ecliptic plane, many of which are the subject of further study, and over 1000 additional candidates. Here we present the results of an ongoing project to follow-up…
Destruction of Long-period Comets
Jewitt, David
We identify a sample of 27 long-period comets for which both nongravitational accelerations and Lyα-based gas production rates are available. Seven of the 27 comets (i.e., ~25%) did not survive perihelion because of nucleus fragmentation or complete disintegration. Empirically, the latter nuclei have the smallest gas production rates and the large…