Astronomy & Telescopes Archives

Completeness of our GaiaPMEX search for binaries. Each panel represents one of the GaiaPMEX references. The shaded area shows the completeness of the combined RUWE+PMa signal, with the dotted blue line and the dashed red line indicating the 50% contour level given by RUWE and PMa alone, respectively. Overplotted are SHINE detections, each assigned to the closest reference star to its target. Squares indicate stars with no RUWE and PMa measurements; triangles represent stars without PMa; dots indicate stars with both RUWE and PMa. The companions are colored according to their detection method: red (DI), gold (RV), green (GaiaNSS), black (GaiaPMEX); those also detected by GaiaPMEX have a black edge. Finally, violet markers indicate companions, only detected by GaiaPMEX, with a minimum mass in the substellar regime. -- astro-ph.EP

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

The SPHERE Infrared Survey For Exoplanets (SHINE) V. Full Sample Characterization

by Keith CowingMay 29, 2026May 29, 2026

Surveys of large stellar samples are the prime means through which the prevalence of exoplanets can be derived, and crucial constraints to planet formation models can be set.

Cartoon illustration (not up to scale) of molecular distribution of detected N-bearing molecules towards NIRS3 based on estimated source sizes and temperatures. The direction of CO (J = 3–2) outflow is obtained from Zinchenko et al. (2020). -- astro-ph.GA

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

Digging Into The Massive Protostar S255IR NIRS3: A Study of Nitrogen-Bearing Molecules and Their Prebiotic Chemistry

by Keith CowingMay 28, 2026May 28, 2026

The study of complex nitrogen (N)-bearing molecules is essential for probing the physical and chemical evolution of star-forming regions.

Left: GO 2433’s F770W map of NGC 891, with the H2 S (1) maps for the four MRS pointings in our study, in colour. The contours in the background and inset images are F770W surface brightnesses. The white cross marks the centre of the galaxy. Right: Total intensity maps for a few key dust features in all observations. The maps are obtained by fitting a 1D model to each pixel independently, and summing the intensities of all sub-features belonging to the same complex. Because the 11.2 µm feature dominates the emission, each map is shown with its own scaling; we focus on the variations within each maps rather than the absolute intensity values. Non-fit pixels, skipped by PAHFIT, are shown in white. -- astro-ph.GA

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

Survival Of Very Small Carbonaceous Dust Grains In The Inner-CGM Of NGC 891 From JWST/MIRI MRS

by Keith CowingMay 28, 2026May 28, 2026

We present new spectroscopic observations of the inner circumgalactic medium (CGM) of NGC 891 taken with the Mid-Infrared Imager/Medium Resolution Spectroscopy instrument onboard JWST, in four positions: two near the […]

Schematic overview of the interior model of Trappist1f,g,h. The ice I layer is divided into a conductive and a convective sublayer. The thermal model determines the thickness of the conductive and convective layers, Rice,I , RHPI, and Qeq. The tidal model computes the tidal heating rates in the HPI, and the mantle. The layer boundaries are not to scale. Note that the convective layer -- astro-ph.EP

Astrogeology, Astronomy & Telescopes, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Icy Worlds, Imaging & Spectroscopy, Press Release, TRAPPIST-1, Water/Hycean Worlds & Oceanography

Interior-Atmosphere Coupling on TRAPPIST-1 f, g, and h: Cryovolcanic Water Exospheres and Infrared Detectability

by Keith CowingMay 28, 2026May 28, 2026

We investigate the interior structures and cryovolcanic observability of the exoplanets TRAPPIST-1f, g, and h. Our aim is to determine which interior configurations can sustain subsurface liquid water oceans in […]

Astronomy & Telescopes, Exoplanets, -moons, -comets, Gaia - Planetary Perspectives, Habitable Zones, Radiation, Space Weather & Heliophysics, Status Report

Exploring Space Weather From Young Solar-like Stars as Windows to Exoplanetary Habitability

by Keith CowingMay 28, 2026May 28, 2026

Young solar-like stars are efficient generators of magnetic activity, superflares, coronal mass ejections (CMEs), and stellar energetic particles. These phenomena drive the early evolution of stars and shape the habitability […]

The logarithmic number ratios of elemental abundances (ordered in increasing volatility/decreasing condensation temperature)

Astronomy & Telescopes, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

From Hubble to HWO: Bridging the Frontier of White Dwarf Exoplanet Science

by Keith CowingMay 28, 2026May 28, 2026

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 […]

Semi-major axis versus planetary mass diagram for a population of transiting exoplanets. Stars are symbols for the planets observed in a ground-based atmospheric escape campaign. Planets above the red (orange) curve cannot have lost more than 50% (10%) of their initial mass M0 to photoevaporation. For more details, see Vissapragada et al. (2022). -- astro-ph.SR

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gaia - Planetary Perspectives, Habitable Zones, Imaging & Spectroscopy, Mars, Status Report

The Role Of The Hubble Space Telescope In Advancing Our Understanding Of Atmospheric Escape In Exoplanets

by Keith CowingMay 28, 2026May 28, 2026

An important evolutionary pathway for planetary atmospheres is escape to space, which has been studied on Earth and Mars for several decades and more recently in exoplanets.

These panels represent the Lomb-Scargle power for different activity cycle power frequencies found in the dataset of Alpha Centauri A and B. The highest power for a period > 5 years is marked by the blue dashed line which amounts to 22.2 years for Alpha Centauri A and 8.2 years for Alpha Centauri B. Bottom: These panels represent the sinusoidal fit to the MgII index data for Alpha Centauri A and B. The solar MgII index is overlaid in the figure for reference. The solar MgII index is obtained from the LISIRD website (Leise et al. 2019). -- astro-ph.SR

Alpha 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

by Keith CowingMay 27, 2026May 27, 2026

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 […]

Pole-on views of the orbital positions of Proxima d (small black dot) and b (large black dot) during each enhanced-emission event. The telescope symbol and vertical dotted line indicate the time of inferior conjunction and the observer’s direction. Orbital motion is clockwise. Each configuration is labeled by its BJD. Proxima Centauri is represented by the central orange dot. -- astro-ph.EP

Alpha Centauri, Astronomy & Telescopes, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Proxima Centauri, Radiation, Space Weather & Heliophysics, Status Report

Star-planet Interaction In The Proxima System

by Keith CowingMay 26, 2026May 26, 2026

(Abridged) We search for evidence of star-planet magnetic interactions in the nearby Proxima Centauri planetary system using high-quality, high-spectral-resolution optical observations.

ShaneAO/ShARCS high-resolution imaging of HIP 18512 (left), ShaneAO/ShARCS imaging of HIP 45839 (center), and Keck/NIRC2 high-contrast imaging of HIP 45839 (right). Each image is oriented such that north is up and and east is to the left. HIP 18512 shows a binary at a separation of 10. ′′9 and a position angle of 12.7 ◦ . The Keck/NIRC2 imaging of HIP 45839 shows a faint source at 5. ′′3 which is not consistent with the observed RV trend and astrometric acceleration. A zoomed-in 0. ′′4 × 0. ′′4 cutout of the source is shown in the inset panel. Images are displayed with an arcsinh stretch to capture a large dynamic range (Lupton et al. 2004). -- astro-ph.EP

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

Gaia Exoplanet Orbits, Demographics, and Evolution Survey (GEODES): Characteristics of Three Long-Period Companions Accelerating their Host Stars

by Keith CowingMay 26, 2026May 26, 2026

The upcoming release of Gaia DR4 will yield thousands of giant planet candidates, eventually enabling studies of giant planet eccentricities, masses, and occurrence rates across a broad range of stellar […]

Astronomy & Telescopes

The SPHERE Infrared Survey For Exoplanets (SHINE) V. Full Sample Characterization

Digging Into The Massive Protostar S255IR NIRS3: A Study of Nitrogen-Bearing Molecules and Their Prebiotic Chemistry

Survival Of Very Small Carbonaceous Dust Grains In The Inner-CGM Of NGC 891 From JWST/MIRI MRS

Interior-Atmosphere Coupling on TRAPPIST-1 f, g, and h: Cryovolcanic Water Exospheres and Infrared Detectability

Exploring Space Weather From Young Solar-like Stars as Windows to Exoplanetary Habitability

From Hubble to HWO: Bridging the Frontier of White Dwarf Exoplanet Science

The Role Of The Hubble Space Telescope In Advancing Our Understanding Of Atmospheric Escape In Exoplanets

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

Star-planet Interaction In The Proxima System

Gaia Exoplanet Orbits, Demographics, and Evolution Survey (GEODES): Characteristics of Three Long-Period Companions Accelerating their Host Stars

NASA SMD ROSES-25 Amendment 68: New Opportunity: D.8 Habitable Worlds Observatory Precursor Science Investigations [UPDATE 2]

RED26 Astrobiology Lectures Are Now Online

The Refractory Fraction Of Phosphorus In Planet-forming Discs

Atmosphere Detected On The Coldest Lava World To Date

Thermal Anomaly Discovered Below Mars’s South Pole