Results 1 to 10 of about 226 (101)

The Impact of Bayesian Hyperpriors on the Population-level Eccentricity Distribution of Imaged Planets

open access: yesThe Astronomical Journal, 2023
Orbital eccentricities directly trace the formation mechanisms and dynamical histories of substellar companions. Here, we study the effect of hyperpriors on the population-level eccentricity distributions inferred for the sample of directly imaged ...
Vighnesh Nagpal   +5 more
doaj   +1 more source

Metallicity and Spectral Evolution of WASP 39b: The Limited Role of Hydrodynamic Escape

open access: yesThe Astrophysical Journal Letters, 2023
The recent observations on WASP-39 b by JWST have revealed hints of high metallicity within the atmosphere compared to its host star. There are various theories on how these high metallic atmospheres emerge.
Amy J. Louca   +2 more
doaj   +1 more source

The JWST Early Release Science Program for Direct Observations of Exoplanetary Systems I: High-contrast Imaging of the Exoplanet HIP 65426 b from 2 to 16 μm

open access: yesThe Astrophysical Journal Letters, 2023
We present JWST Early Release Science coronagraphic observations of the super-Jupiter exoplanet, HIP 65426b, with the Near-Infrared Camera (NIRCam) from 2 to 5 μ m, and with the Mid-Infrared Instrument (MIRI) from 11 to 16 μ m. At a separation of ∼0.″82 (
Aarynn L. Carter   +110 more
doaj   +1 more source

TOI-3984 A b and TOI-5293 A b: Two Temperate Gas Giants Transiting Mid-M Dwarfs in Wide Binary Systems

open access: yesThe Astronomical Journal, 2023
We confirm the planetary nature of two gas giants discovered by TESS to transit M dwarfs with stellar companions at wide separations. TOI-3984 A ( J = 11.93) is an M4 dwarf hosting a short-period (4.353326 ± 0.000005 days) gas giant ( M _p = 0.14 ± 0.03 ...
Caleb I. Cañas   +32 more
doaj   +1 more source

The Unusual M-dwarf Warm Jupiter TOI-1899 b: Refinement of Orbital and Planetary Parameters

open access: yesThe Astronomical Journal, 2023
TOI-1899 b is a rare exoplanet, a temperate warm Jupiter orbiting an M dwarf, first discovered by Cañas et al. (2020) from a TESS single-transit event.
Andrea S. J. Lin   +33 more
doaj   +1 more source

Detecting Solar System Analogs through Joint Radial Velocity/Astrometric Surveys

open access: yesThe Astronomical Journal, 2023
Earth-mass exoplanets on year-long orbits and cool gas giants (CGG) on decade-long orbits lie at the edge of current detection limits. The Terra Hunting Experiment (THE) will take nightly radial velocity (RV) observations on HARPS3 of at least 40 bright ...
Daniel A. Yahalomi   +3 more
doaj   +1 more source

The JWST Early-release Science Program for Direct Observations of Exoplanetary Systems II: A 1 to 20 μm Spectrum of the Planetary-mass Companion VHS 1256–1257 b

open access: yesThe Astrophysical Journal Letters, 2023
We present the highest fidelity spectrum to date of a planetary-mass object. VHS 1256 b is a
Brittany E. Miles   +110 more
doaj   +1 more source

Day–Night Transport-induced Chemistry and Clouds on WASP-39b: Gas-phase Composition

open access: yesThe Astrophysical Journal Letters, 2023
JWST has recently detected the first robust photochemical product on an exoplanet: sulfur dioxide (SO _2 ) on WASP-39b. The data from the NIRISS instrument also reveal signs of partial coverage of clouds.
Shang-Min Tsai   +3 more
doaj   +1 more source

Small Planets around Cool Dwarfs: Enhanced Formation Efficiency of Super-Earths around M Dwarfs

open access: yesThe Astrophysical Journal Letters, 2023
Current measurements of planet population as a function of stellar mass show three seemingly contradictory signatures: close-in super-Earths are more prevalent around M dwarfs than FGK dwarfs; inner super-Earths are correlated with outer giants; and ...
Yayaati Chachan, Eve J. Lee
doaj   +1 more source

Forming Gas Giants around a Range of Protostellar M-dwarfs by Gas Disk Gravitational Instability

open access: yesThe Astrophysical Journal, 2023
Recent discoveries of gas giant exoplanets around M-dwarfs from transiting and radial velocity surveys are difficult to explain with core-accretion models. We present here a homogeneous suite of 162 models of gravitationally unstable gaseous disks. These
Alan P. Boss, Shubham Kanodia
doaj   +1 more source

Home - About - Disclaimer - Privacy