Gaia DR3 Archives

probability density function (PDF) of the ages of solar twins determined with MKs

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

Solar Twins In Gaia DR3 GSP-Spec II. Age Distribution And Its Implications For The Sun’s Migration

by Keith CowingMarch 13, 2026March 13, 2026

Solar twins are among the most powerful tracers of Galactic disk evolution owing to their unique property of sharing nearly solar metallicities ([Fe/H] ~ 0) while spanning a wide range […]

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.

Near-UV to visible reflectance spectrum of 3I/ATLAS obtained with OSIRIS/GTC and normalized to unity at 5500 Å. Normalized reflectance of 1I/’Oumuamua (in brown) from Fitzsimmons et al. (2018) and 2I/Borisov (in green) from de León et al. (2020) are also shown for comparison, together with D-type spectral taxon from DeMeo et al. (2009). -- astro-ph.EP

Astrochemistry, Astrogeology, Astronomy & Telescopes, Biosignatures & Paleobiology, Icy Worlds, Imaging & Spectroscopy, Interstellar, Status Report

Assessing Interstellar Comet 3I/ATLAS With The 10.4 m Gran Telescopio Canarias And The Two-meter Twin Telescope

by Keith CowingJuly 25, 2025July 25, 2025

Context. Theories of the formation and evolution of small bodies in planetary systems predict that they may escape into interstellar space at any time.

The colour-magnitude diagram of the CPM companion stars to host stars of confirmed exoplanets (left) and TOI PCs (right), corrected for G band extinction. The background consists of the primary and secondary stars in the El-Badry et al. (2021) binary catalog. The companion sources below the main sequence are discussed in Section 6.1. -- astro-ph.EP

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

A High Stellar Multiplicity Rate Amongst TESS Planet Candidates In The Neptunian Desert Using Gaia DR3 Astrometry

by Keith CowingJuly 1, 2025July 1, 2025

We aim to discover whether the stellar multiplicity rate may provide information on the origin of recently discovered planets in the Neptunian Desert.

Comparison of the orbit posteriors incorporating different sources of data. The blue dots mark the location of the planet on 2025-01-01. The colors of the orbit draws match those in Figure 2 for easier cross-referencing. The bottom right panel shows the outer debris disk model fit to ALMA data by Booth et al. (2023). The ❉ indicates two models containing only RV data and only absolute astrometry data respectively, and whose posteriors are therefore completely independent. The models indicated by ✦ include RV data, but distinct sets of astrometric data, making the position angles they indicate on 2025-01-01 effectively independent. -- astro-ph.EP

Astronomy & Telescopes, Epsilon Eridani, Exoplanets, -moons, -comets, Status Report

Revised Mass and Orbit of Epsilon Eridani b: A 1 Jupiter-Mass Planet on a Near-Circular Orbit

by Keith CowingMarch 4, 2025August 13, 2025

The mature Jovian planet ε Eridani b orbits one of the closest sun-like stars at a moderate separation of 3.5 AU, presenting one of the best opportunities to image a […]

Selection of the astrometric solutions for our mock astrometric binary catalog. This figure in inspired by Figure 3 of Halbwachs et al. (2023), who present the same quantities for the astrometric solutions of real sources published in Gaia DR3. Upper left panel shows all solutions with a0/σa0 > 5 and F2 < 25. The cloud of points at long Porb and low fm, ast consists mostly of good solutions, while the vertical stripes of solutions with high fm, ast and short periods are all spurious. In the upper right, green and gray show the distributions of solutions with fm, ast < 0.3 M⊙ (presumed mostly reliable) and fm, astt > 0.3 M⊙ (presumed mostly spurious). Black line shows the empirical cut (Equation 20) below which solutions are discarded. Bottom panels show only solutions that pass this cut. Red lines in these panels show additional cuts applied to the final solutions: only solutions below (left panel) and above (right panel) the red lines were retained. -- astro-ph.GA

Astronomy & Telescopes, Brown Dwarfs, Exoplanets, -moons, -comets, Gas Giants, Imaging & Spectroscopy, Status Report, Stellar Cartography

A Generative Model for Gaia Astrometric Orbit Catalogs: Selection Functions for Binary Stars, Giant Planets, and Compact Object Companions

by Keith CowingNovember 7, 2024November 7, 2024

Astrometry from Gaia DR3 has produced a sample of ∼170,000 Keplerian orbital solutions, with many more anticipated in the next few years. These data have enormous potential to constrain the […]

Sky positions of exoplanet-hosting stars projected on Molleweide map. HZS are denoted by yellow-green circles, while the remaining population of exoplanets is represented by gray circles. The studied sample of 84 HZS, located within 220 pc of the Sun, is represented by crossed yellow-green circles. The three high-density HZS located near the galactic plane are labeled 1, 2 and 3 in white. The colorbar represents the stellar density, i.e., the number of stars having G ≥ 15 within a radius of 5 arcmin. -- astro-ph.HE

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Habitable Zones, Imaging & Spectroscopy, Status Report, Stellar Cartography, Water/Hycean Worlds & Oceanography

The 10 pc Neighborhood of Habitable Zone Exoplanetary Systems: Threat Assessment from Stellar Encounters & Supernovae

by Keith CowingOctober 31, 2024October 31, 2024

The habitability of a planet is influenced by both its parent star and the properties of its local stellar neighborhood. Potential threats to habitability from the local stellar environment mainly […]

Left: A zoom-in on the stacked Kp-band image of MOA-2011-BLG-262, with the brighter source star near center and the faint lens star candidate indicated with the cross-hair. Middle: Zoomed-in frame with a single-PSF model fit to the source star and subtracted from the frame, the remaining flux comes primarily from the lens and is indicated with the cross-hair. The other bright nearby stars are also subtracted with the same PSF model. Right: Zoomed-in frame with the PSF model fit and subtracted from the source and lens stars. North is up, East is left in all frames. Note there are several faint ambient field stars that are at or below the default detection threshold in DAOPHOT. -- astro-ph.EP

Astronomy & Telescopes, Exoplanets, -moons, -comets, Gaia Mission, Gas Giants, Imaging & Spectroscopy, Interstellar, Status Report, Stellar Cartography

A Candidate High-Velocity Exoplanet System In The Galactic Bulge

by Keith CowingOctober 16, 2024November 16, 2024

We present an analysis of adaptive optics (AO) images from the Keck-I telescope of the microlensing event MOA-2011-BLG-262. The original discovery paper by Bennett et al. 2014 reports two distinct […]

The data source: http://www.johnstonsarchive.net/astro/nearstar.html The coordinate scales are marked in light years. The third dimension is shown with color (with pink being closest to the viewer, and cyan the farthest). The mass of a star is shown with the size of its circle, and of the font. Inter-stellar distances shorter than 10 light years are shown as lines. The longer the distance, the dimmer is the line. Source -- Wikipedia

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

Multiplicity Of Stars With Planets In The Solar Neighbourhood

by Keith CowingJuly 30, 2024

Aims: We intended to quantify the impact of stellar multiplicity on the presence and properties of exoplanets.

Gaia DR3

Solar Twins In Gaia DR3 GSP-Spec II. Age Distribution And Its Implications For The Sun’s Migration

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

Assessing Interstellar Comet 3I/ATLAS With The 10.4 m Gran Telescopio Canarias And The Two-meter Twin Telescope

A High Stellar Multiplicity Rate Amongst TESS Planet Candidates In The Neptunian Desert Using Gaia DR3 Astrometry

Revised Mass and Orbit of Epsilon Eridani b: A 1 Jupiter-Mass Planet on a Near-Circular Orbit

A Generative Model for Gaia Astrometric Orbit Catalogs: Selection Functions for Binary Stars, Giant Planets, and Compact Object Companions

The 10 pc Neighborhood of Habitable Zone Exoplanetary Systems: Threat Assessment from Stellar Encounters & Supernovae

A Candidate High-Velocity Exoplanet System In The Galactic Bulge

Multiplicity Of Stars With Planets In The Solar Neighbourhood

Mars Curiosity Reaches 1-Kilometer Elevation Gain

Dragonfly Gets Wired Up While Titan Landing Area Is Named

Amplified Cooling Of Snowball Earth From A Salt-albedo Feedback

Prebiotic Cationic Amino Acids Support Formation Of An Ancient Protein Fold

The Ultraviolet Spectrograph on ESA’s Jupiter Icy Moons Explorer Mission (JUICE-UVS)