exoplant Archives - Astrobiology

The phase curve of a planet over one rotation at eight different illumination phases. The images at the right show renderings of the planet’s illuminated surface throughout the observation. Each curve represents a different viewing geometry, the observer-planet-star angle, with the corresponding planetary illumination phase shown by the colored circles in the legend. The top (blue) curve shows a fully illuminated planet, while the lower curves show various partial illumination scenarios down to a completely dark planet (purple). The gray curve represents the classical edge-on viewing case exhibiting the full range of phase variations. -- astro-ph.SR

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Ice Giant, Icy Worlds, Imaging & Spectroscopy, Status Report

Requirements For Joint Orbital Characterization of Cold Giants and Habitable Worlds with Habitable Worlds Observatory

by Keith CowingJuly 30, 2025July 30, 2025

We determine optimal requirements for the joint detection of habitable-zone planets and cold giant planets with the Habitable Worlds Observatory (HWO).

Euclid images (log scale) of the proto-brown dwarf candidates J041828 and J041938 from Palau et al. (2012) and Morata et al. (2015). -- astro-ph.SR

Astronomy & Telescopes, Brown Dwarfs, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Interstellar, Status Report

Free-floating Planetary Mass Objects In LDN 1495 From Euclid Early Release Observations

by Keith CowingMarch 21, 2025March 21, 2025

Context. Substellar objects, including brown dwarfs and free-floating planetary-mass objects, are a significant product of star formation.

Comparison of nested POSEIDON Model B retrievals with and without H− and AlO, zooming on the 0.2 to 1.05 µm region. We display median retrieved spectra (solid lines) and 1σ confidence regions (shaded regions). Model B with both H− and AlO (blue) is the best fit model, but only due to imparting fine structure to fit the STIS slope. Future observations of the 0.2-0.8 µm region will provide more reliable inferences of metal species. -- astro-ph.EP

Astrochemistry, Astronomy & Telescopes, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gas Giants, Imaging & Spectroscopy, Status Report

JWST-TST DREAMS: A Precise Water Abundance for Hot Jupiter WASP-17b from the NIRISS SOSS Transmission Spectrum

by Keith CowingDecember 11, 2024December 11, 2024

Water has proven to be ubiquitously detected in near-infrared (NIR) transmission spectroscopy observations of hot Jupiter atmospheres, including WASP-17b.