White dwarf stars, the endpoint of stellar evolution for 97% of stars in our Milky Way, offer a unique and powerful window into the bulk elemental composition of rocky exoplanetary […]
white dwarf
![The best-fit PICASO retrieval temperature-pressure (TP) profile is plotted as a solid blue line with the temperature-pressure knots indicated in solid blue circles. The light blue shaded region indicates the 3σ confidence interval of the retrieved TP profiles. The tightly constrained TP profiles in the 1–10 bar range match with the peak of the 3–5 µmcontribution function plotted in the right panel. The retrieved TP profile based on MIRI-LRS 5–11.7 µmspectrum in Voyer et al. (2025) is plotted in solid purple along with the 3σ uncertainty plotted as light-purple shaded region. The condensation curves of H2O, Na2S, and KCl at solar metallicity are plotted with blue, orange, and green dashed lines respectively. For reference, the solid black line shows the TP profile of the best-fit Elf Owl grid model ([M/H] = -1, C/O = 1.5, log(g) = 3.23, log(Kzz) = 7, Teff= 350 K). Right panel: The contribution function map of the best-fit PICASO retrieval results shows that most of the 3–5 µmflux is emitted from 0.1–10 bar region. -- astro-ph.EP](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/02/JWST-Spectral-Retrieval.png?resize=1200%2C719&ssl=1)
Posted inAstrochemistry, Astronomy & Telescopes, Exoplanets, -moons, -comets, Icy Worlds, Imaging & Spectroscopy, Press Release
JWST Spectral Retrieval Of Cold Directly Imaged Planet WD0806 b And The First
WD0806 b is a rare exoplanet companion orbiting a white dwarf, currently with a projected orbital distance of 2500 au. The Spitzer mid-IR photometry suggests that the temperature is as […]
Posted inAstrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Imaging & Spectroscopy, Interstellar, Press Release
Astrochemistry: Webb Reveals The Helix Nebula In Glistening Detail
One of the closest planetary nebulas to Earth, the Helix Nebula has become a favorite among astronomers using ground- and space-based telescopes to study the final moments of a dying […]
Posted inAstrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report
The Future of Evolved Planetary Systems
Understanding the formation, evolution, and chemical diversity of exoplanets are now central areas of astrophysics research. White dwarfs provide a uniquely sensitive laboratory for studying the end stages of planetary-system […]
Posted inExoplanets, -moons, -comets, Habitable Zones, Status Report, Stellar Cartography
General Relativity Can Prevent a Runaway Greenhouse on Potentially Habitable Planets Orbiting White Dwarfs
Planets orbiting in the habitable zones of white dwarfs have recently been proposed as promising targets for biosignature searches.
Posted inAstrochemistry, Astrogeology, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Icy Worlds, Imaging & Spectroscopy, Status Report
Discovery Of An Icy And Nitrogen-rich Extrasolar Planetesimal
White dwarfs accreting planetary debris provide detailed insight into the bulk composition of rocky exo-planetesimals. However, only one Kuiper-Belt analogue has been identified in that way so far.
Posted inAstrochemistry, Astronomy & Telescopes, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Icy Worlds, Status Report
Detecting Water Ice And Vapor Disks Originating From Icy Planetary Bodies Around White Dwarfs With Future PRIMA Observations
Observations of atmospheres of polluted white dwarfs provide insights into the elemental composition of accreted exoplanets and exo-asteroids.
Posted inAstronomy & Telescopes, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Icy Worlds, Imaging & Spectroscopy, Press Release, Stellar Cartography
Do White Dwarfs Sample Water-Rich Planetary Material?
Polluted white dwarfs offer a unique way to directly probe the compositions of exoplanetary bodies.
![LEFT: Predicted 22Ne mass fraction as a function of metallicity for the WD remnants of stars in the Hypatia Catalog (Hinkel et al. 2014). The colors represent [N/H] for the same stars. MIDDLE and RIGHT: C and N abundances of the same stars from the Hypatia Catalog. The color bars represent the predicted neon mass fraction, X(22Ne), in their remnants. Two chemically peculiar low-metallicity objects, BD+80 245 and HD 19445, are labeled and marked as stars. -- astro-ph.SR](https://i0.wp.com/astrobiology.com/wp-content/uploads/2025/08/The-Fraction-of-Distilled.png?resize=1200%2C699&ssl=1)
Posted inAstronomy & Telescopes, Habitable Zones, Imaging & Spectroscopy, Status Report, Stellar Cartography
The Fraction Of Distilled White Dwarfs With Long-Lived Habitable Zones
After carbon and oxygen, 22Ne is the most abundant element in white dwarf interiors. As C/O white dwarfs (WDs) crystallize, they are predicted to go through a distillation process in […]
Posted inAstronomy & Telescopes, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Gas Giants, Icy Worlds, Imaging & Spectroscopy, Status Report
Thermal Emission and Confirmation of the Frigid White Dwarf Exoplanet WD 1856+534b
We report the detection of thermal emission from and confirm the planetary nature of WD 1856+534b, the first transiting planet known to orbit a white dwarf star.