![Dereddened Gaia CMD with PARSEC isochrones overplotted. Black points show Gaia DR3 stars corrected for extinction and reddening using band-specific coefficients. Solid curves show isochrones spanning ages from 1 to 13 Gyr at the reference metallicity. The dotted curves highlight 1 Gyr isochrones computed at the lower (-0.4 dex) and upper (+0.4 dex) metallicity values in the sample, illustrating the range of CMD permitted by the observed metallicity distribution. This comparison demonstrates the impact of metallicity on isochrone placement relative to the data. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/09/Precise.png?resize=1200%2C718&ssl=1)
[astro-ph.EP] Accurate stellar ages are fundamental to interpreting the evolutionary histories of habitable zone (HZ) planets. Because stellar luminosity evolves over time, HZ boundaries migrate outward, meaning that present-day HZ […]
photometry
Posted inExoplanets, -moons, -comets
Astro-Hunters: Machine Learning For Exoplanet Transit Detection In TESS Photometry
[astro-ph.EP] Finding planets beyond the Solar System is now largely a data-analysis problem: photometric surveys return far more stellar light curves than can be inspected by eye, and machine learning […]
Posted inExoplanets, -moons, -comets
Atmospheric Diversity of Giant Planet Analogs from 3-5µm with SPHEREx
[astro-ph.EP]. The emergent spectra of giant planets peak at thermal infrared wavelengths (3-5um) and possess atmospheric features in this regime that trace carbon chemistry, vertical mixing, clouds, and composition.
![[TOP] Example observations of (2060) Chiron for survey/telescopes (left) ATLAS, (middle) ZTF, and (right) LCO/LOOK. [BOTTOM] Example observations of 103P/Hartley 2 for survey/telescopes (left) ATLAS, (middle) ZTF, and (right) LCO/LOOK. -- astro-ph.EP](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/07/Multi-year.png?resize=1200%2C720&ssl=1)
Posted inComets and Asteroids
Multi-year Ground-Based Survey Photometry of Active Comet 103P/Hartley 2 and Centaur (2060) Chiron: A Tale of Two Comets in the Pre-LSST Era
[astro-ph.EP] Comets and Centaurs trace the evolution of trans-Neptunian objects (TNOs) into the inner solar system.
Posted inExoplanets, -moons, -comets
The GAPS Programme at TNG LXXIV. A Reanalysis Of The Planetary Systems TOI-1272 And TOI-1694 With HARPS-N And Retraction Of The Planetary Interpretation Of TOI-1272 c
[astro-ph.EP] Hot Neptunes are close-in exoplanets that occupy a sparsely populated region of parameter space known as the “hot-Neptune desert”.
Posted inAstronomy & Telescopes, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report, Stellar Cartography
COUNTESS I: A Uniformly Vetted Catalog of Known and New Transiting Exoplanets in the TESS Northern Continuous Viewing Zone
The Transiting Exoplanet Survey Satellite (TESS) has transformed the study of nearby exoplanetary systems; however, its nominal observing strategy limits sensitivity to planets with orbital periods shorter than ∼10 days […]
Posted inAstrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Imaging & Spectroscopy, Interstellar, Status Report
The First Glimpse of Water Ice Absorption Map in the Milky Way
Interstellar ice plays a key role in the thermal evolution of the interstellar medium and in astrochemical pathways, yet its large-scale distribution remains poorly constrained.
Posted inAlpha Centauri, Astronomy & Telescopes, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Space Weather & Heliophysics, Status Report, Stellar Cartography
Near UV Stellar Activity and Brightness Fluctuations of the Alpha Centauri AB Star System from Weeks to Decades — Inputs for Reflected Light Spectroscopy with HWO
We present the most comprehensive near-ultraviolet (NUV: 2550-3255 Angstrom) activity record to date for the Alpha Centauri AB system, combining archival IUE and HST observations spanning nearly five decades with […]
Posted inAstronomy & Telescopes, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report
An Ultra-Short Period Super-Earth And A Sub-Neptune Orbiting The K Dwarf TOI-4311
We report the discovery and characterisation of the multi-planetary system around TOI-4311, a K dwarf kinematically between the Galactic thick disk and Hercules stream. TOI-4311 hosts an ultra-short-period super-Earth (P∼0.99 […]
Posted inExoplanets, -moons, -comets, Status Report
A Climate-Constrained Bayesian Inverse Method for JWST Rocky Exoplanet Eclipse Spectra: A Case Study of LTT 1445A b
Determining whether temperate rocky exoplanets orbiting M stars retain atmospheres is currently a central goal of exoplanet astronomy. To this end, the James Webb Space Telescope has begun searching for […]