Objects from interstellar space, such as rogue planets and asteroids, can become permanently trapped in the Sun’s orbit as a result of the combined gravitational effects of the Sun and […]
Brown Dwarfs
Posted inAstronomy & Telescopes, Brown Dwarfs, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Interstellar, Status Report
Between Stars And Planets: Brown Dwarfs in IC 348
Not quite stars, not quite planets — brown dwarfs are objects that fall in between. Within the star cluster shown in this image, Webb observed the tiniest, free-floating brown dwarf […]
Posted inAstronomy & Telescopes, Brown Dwarfs, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report, Stellar Cartography
Astrometry As A Tool For Discovering And Weighing Faint Companions To Nearby Stars
This tutorial covers the use of absolute astrometry, in particular from the combination of the Hipparcos and Gaia missions, to identify faint companions to nearby stars and to measure the […]
Posted inAstrochemistry, Astronomy & Telescopes, Atmospheres, Climate, Weather, Brown Dwarfs, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report
Probing the Heights and Depths of Y Dwarf Atmospheres: A Retrieval Analysis of the JWST Spectral Energy Distribution of WISE J035934.06−540154.6
We present an atmospheric retrieval analysis of the Y0 brown dwarf WISE J035934.06−540154.6 using the low-resolution 0.96–12 μm JWST spectrum presented in Beiler_2023. We obtain volume number mixing ratios of […]
![Left: C/O as a function of projected separation or semi-major axis for the eight companions in this study. The points are sized by companion mass, using the mass legend in the right panel. The blue line and region show the solar C/O value from Asplund et al. (2021). Right: In color: 1σ contours of C/O and [C/H] for the eight companions, which are all consistent with solar composition (intersection of dashed gray lines) to the 2σ level. In § 6.4.1, we justify that their host stars likely have solar composition as well. We overplot hot Jupiters which have abundance measurements for at least one oxygen-bearing and one carbon-bearing species from JWST or high-resolution spectroscopy as black points (Alderson et al. 2023; August et al. 2023; Bean et al. 2023; Bell et al. 2023; Brogi et al. 2023; Finnerty et al. 2024; Xue et al. 2024), which are also sized by mass. The hot Jupiters show considerable scatter and super-solar (and super-stellar) metallicities except for one planet, unlike our companions which cluster around solar (and stellar) composition. -- astro-ph.EP](https://i0.wp.com/astrobiology.com/wp-content/uploads/2024/06/Are-These-Planets.png?resize=1200%2C719&ssl=1)
Posted inAstronomy & Telescopes, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Brown Dwarfs, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report, Stellar Cartography
Are These Planets Or Brown Dwarfs?
Using Keck Planet Imager and Characterizer (KPIC) high-resolution (R~35000) spectroscopy from 2.29-2.49 μm, we present uniform atmospheric retrievals for eight young substellar companions with masses of ~10-30 MJup, orbital separations […]
Posted inBrown Dwarfs, Exoplanets, -moons, -comets, Status Report
Dark Kinetic Heating of Exoplanets and Brown Dwarfs
Dark kinetic heating of neutron stars has been previously studied as a promising dark matter detection avenue. Kinetic heating occurs when dark matter is sped up to relativistic speeds in […]
Posted inAstronomy & Telescopes, Atmospheres, Climate, Weather, Brown Dwarfs, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Mapping, Geodesy, Cartography, Bathymetry, Status Report
Prioritizing High-Precision Photometric Monitoring of Exoplanet and Brown Dwarf Companions with JWST — Strategic Exoplanet Initiatives with HST and JWST White Paper
We advocate for the prioritization of high-precision photometric monitoring of exoplanet and brown dwarf companions to detect brightness variability arising from features in their atmospheres. Measurements of photometric variability provide […]
Posted inAstronomy & Telescopes, Brown Dwarfs, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report
How Rare Are TESS Free-Floating Planets?
Recently, Kunimoto et al. claimed that a short-lived signal in the Transiting Exoplanet Survey Satellite (TESS) Sector 61 database was caused by a microlensing event with a terrestrial-mass free-floating planet […]
Posted inAstronomy & Telescopes, Atmospheres, Climate, Weather, Brown Dwarfs, Exoplanets, -moons, -comets, Gas Giants, Imaging & Spectroscopy, Press Release
Fresh View Of The Hot Brown Dwarf HD 984 B Through High-resolution Spectroscopy
Context. High-resolution spectroscopy has the potential to drive a better understanding of the atmospheric composition, physics, and dynamics of young exoplanets and brown dwarfs, bringing clear insights into the formation […]
Posted inAstrochemistry, Astronomy & Telescopes, Atmospheres, Climate, Weather, Brown Dwarfs, Exoplanets, -moons, -comets, Gas Giants, Imaging & Spectroscopy, Status Report
Methane Emission From a Cool Brown Dwarf
Beyond our solar system, aurorae have been inferred from radio observations of isolated brown dwarfs (e.g. Hallinan et al. 2006; Kao et al. 2023). Within our solar system, giant planets […]