2MASS Archives - Astrobiology

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]

Exoplanets, -moons, -comets

Precise Stellar Age Constraints and Habitable Zone Evolution in Exoplanet Systems

by Keith CowingSeptember 4, 2026September 4, 2026

[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 […]

Temperature versus surface gravity diagram with the empirical CH4 onset line.

Exoplanets, -moons, -comets

JWST Color Sequence Of Transiting Exoplanets And Directly Imaged Substellar Objects

by Keith CowingAugust 28, 2026August 28, 2026

[astro-ph.EP] Color-magnitude diagrams (CMDs) have been foundational across astrophysics, from galaxies and stars to brown dwarfs, and JWST now extends them to transiting exoplanets and self-luminous substellar objects at overlapping […]

The distribution of planetary radius and orbital period of TOIs and new false positives and planet candidates. COUNTESS discovered 38 new planetary signals, with 28 of them being FPs through triceratops validation and LEOVetter pixel-vetting. Note that the square symbols indicate TOI FPs that were successfully recovered as FPs through COUNTESS. -- astro-ph.EP

Astronomy & 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

by Keith CowingJune 15, 2026June 15, 2026

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 […]

Fig. 9: Distribution of water ice. The color map represents the smoothed Aice W1 values, where blue indicates the existence of water ice absorption. Several well-known regions are enclosed in boxes and labeled as regions 1 to 5, they are (1)Orion-Taurus-Perseus (OTP) region, (2)Cygnus Complex, (3)Serpens region, (4)Ophiuchus region and (5)Vela Co -- astro-ph.GA

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Imaging & Spectroscopy, Interstellar, Status Report

The First Glimpse of Water Ice Absorption Map in the Milky Way

by Keith CowingJune 3, 2026June 3, 2026

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.

Starting from the top left corner and moving in a clockwise direction are the companions we detected to 2MASS J01283952-1458042, PM J02024+1034 A, 2MASS J05103956+2946479, 2MASS J07171706-0501031, 2MASS J10430293-0912410, and 2MASS J19445376-2337591. These reconstructed images sometimes contain a third “ghost peak” due to low SNR resulting in a lack of phase information. As noted in Section 3.1, the companions to 2MASS J05103956+2946479 and 2MASS J07171706-0501031 are unbound. -- astro-ph.SR

Astronomy & Telescopes, Exoplanets, -moons, -comets, Status Report, Stellar Cartography

The POKEMON Speckle Survey of Nearby M dwarfs. IV. Distance-Limited Catalog (POKEMON-DLC)

by Keith CowingApril 29, 2026April 29, 2026

The Solar Neighborhood is dominated by stars smaller, colder, and fainter than the Sun: the M dwarfs.

Main panel: comparison among ATLAS9 fluxes for the Sun calculated with suitable ODFs adopting different solar chemical mixtures

Astronomy & Telescopes, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Press Release

KOALA, A New ATLAS9 Database — I. Model atmospheres, Opacities, Fluxes, Bolometric Corrections, Magnitudes And Colours

by Keith CowingJanuary 22, 2026January 22, 2026

We present the KOALA database, a new set of LTE, line-blanketed model atmospheres calculated with the code ATLAS9, together with the corresponding Opacity Distribution Functions and emergent fluxes.

A notional Dyson sphere - Grok via Astrobiology.com

Astronomy & Telescopes, Biosignatures & Paleobiology, Imaging & Spectroscopy, Intelligence & Language, Interstellar, SETI & Technosignatures, Status Report

WISE/CatWISE Constraints On Dysonian Waste-Heat Technosignatures In Nearby Galaxies

by Keith CowingJanuary 17, 2026

We search for galaxy-scale (Dysonian) waste heat in the mid-infrared using WISE. Starting from the 2MASS Redshift Survey (2MRS), we cross-match to CatWISE2020 and AllWISE, apply standard MIR AGN/starburst vetoes […]

Distribution of 339 planets in the stellar effective flux (𝑆eff) versus stellar temperature (𝑇eff) space. Red solid circles indicate the 17 planets orbiting within the EHZ, while gray points depict the remaining planets. Solar system planets are marked with purple circles. The green solid lines correspond to the inner and outer edges of the classical 1D habitable zone, as defined by Kopparapu et al. (2013). The blue dashed line represents the inner edge of the Extended Habitable Zone (EHZ) around M dwarf stars, assuming 30% heat transport efficiency (Wandel 2023a). The brown curve marks the outer edge of the EHZ, determined by the melting of ice sheets driven by geothermal heat (Wandel 2023b). The gray dashed line indicates the tidally locked radius around M dwarf stars. The green shaded region defines the classical HZ and the blue shaded region highlights the extended HZ for tidally locked exoplanets. -- astro-ph.EP

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gaia - Planetary Perspectives, Habitable Zones, Imaging & Spectroscopy, Status Report, Water/Hycean Worlds & Oceanography

Exploring The Habitability And Interior Composition Of Exoplanets Lying Within The Extended Habitable Zone

by Keith CowingJuly 8, 2025July 8, 2025

Studying the habitability, internal structure and composition of exoplanets is crucial for understanding their potential to sustain life beyond our solar system.