Stellar Cartography Archives

A demonstration of the limitations of the PSPT data processing pipeline, which did not process the limb uniformly with the rest of the Solar disc. The solid blue line is the stated extent of the solar disk in the original dataset, and the dashed red line is the extent to which the data has been cleaned. Note between the red and blue lines there exists a slight intensity increase — an example of the difference between the processed and unprocessed data separated by this boundary. -- astro-ph.SR

Astronomy & Telescopes, Imaging & Spectroscopy, Space Weather & Heliophysics, Status Report, Stellar Cartography

Astrometric Exoplanet Detection Survives Solar-like Stellar Contamination

by Keith CowingMay 23, 2026May 23, 2026

Astrometric monitoring of stars provides a promising method for discovery of low-mass planets around nearby Sun-like stars.

HR diagram track of the default case (final mass of 2.2 MJ ; see Table 1), showing its surface temperature (Eqs. 12, 19 or 21, depending on the phase) and total luminosity (Eq. 6). Highlighted key moments show the start point (•), detachment (⋆), the point of maximum luminosity (▼), disk dispersal (■), and the age of Jupiter (+). Table 2 lists the corresponding values for time, mass and radius. In the ascending branch small black triangles (▲) show linearly spaced time indicators every Myr. The black dots (•) represent post-detachment intervals equally spaced in log(time). Grey reference lines show two trends: the predicted slope derived in Sect. A, evaluated with the median late-attached-phase surface density of Σpla = 1.7 g cm−2 (labelled with L ∝ T 8 ), and a constant-radius track for Rp = 1 RJ , which approximates a cooling planet in the evolutionary phase before stellar irradiation becomes relevant (last downturn). -- astro-ph.EP

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

Planetary Formation Tracks On The Hertzsprung-Russell Diagram: Visualising The Processes Of Giant Planet Growth

by Keith CowingMay 21, 2026May 21, 2026

The Hertzsprung-Russell diagram (HRD) is central to stellar astrophysics but has rarely been used to interpret planet formation.

Stellar [α/Fe] versus [Fe/H] for planet-hosting stars analyzed in this work (orange circles). The heat map represents the density of stars from APOGEE DR17 in the [α/M] vs [Fe/H] parameter space for reference. The black line approximately divides the thin and thick disk populations (below and above the line, respectively) as defined by D. H. Weinberg et al. 2019. The red points represent stars from the SPOCS sample from J. M. Brewer et al. (2016). The Sun is over-plotted for reference. -- astro-ph.EP

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

A Uniform Determination Of The Bulk Metallicities And Alpha Enrichments Of Confirmed Exoplanet Systems With TRES

by Keith CowingMay 20, 2026May 20, 2026

We present a uniform spectroscopic characterization of 625 F, G, and K stars hosting 859 confirmed exoplanets using high-resolution archival optical spectra from the Tillinghast Reflector Echelle Spectrograph (TRES).

Kiel diagram of analysed stars. Stars analysed in this work are shown as blue dots, those from M22 as orange stars, and those from T25 as green symbols. The two grids correspond to PARSEC isochrones with ages from 0.1 to 14 Ga, in steps of 0.05 Ga, at solar metallicity (Z = 0.013, in purple) and at super-solar metallicity (Z = 0.06, in pink). The cross in the lower left corner indicates representative 1σ uncertainties for this work ( ∆Teff = 110 K and ∆ log g = 0.04 dex). -- astro-ph.SR

Ariel Mission, Astronomy & Telescopes, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Missions & Hardware, Status Report, Stellar Cartography

Ariel Stellar Characterisation IV. Fundamental Parameters Of 18 Hot Stars In The Ariel Mission Candidate Sample

by Keith CowingMay 15, 2026May 15, 2026

The characterisation of exoplanetary systems depends on the accurate determination of host star parameters.

Comparison of ages for stars with at least one measurement from both asteroseismology and gyrochronology. For stars with only one measurement from either method, the reported age and statistical uncertainties are shown. Gyrochronology generally agrees with asteroseismology for younger stars, but underestimates stellar ages for stars significantly older than the Sun (∼ 4.6 Gyr). astro-ph.SR

Astronomy & Telescopes, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report, Stellar Cartography

The HAges Catalog: Stellar Ages For High Priority HWO Target Stars

by Keith CowingMay 15, 2026May 15, 2026

Precise stellar ages (uncertainties ≲1 Gyr, or ∼20% at solar age) are required to discern evolutionary trends in atmospheric biosignatures of terrestrial habitable zone exoplanets surveyed by the Habitable Worlds […]

Our target wide binaries are marked with colored circles (primaries) and triangles (secondaries) in the 2MASS (K, J − K) and Gaia (G, BP − RP) CMDs. Blue, orange, green, and red denote HD 20782/HD 20781, WASP-160 A/WASP-160 B, K2-54/K2-54 B, and WASP-127/TYC 4916-897-1 pairs, respectively, with the same color scheme adopted in subsequent figures. Grey circles and triangles indicate our initial candidate systems of planet-hosting wide binaries, while the smaller background symbols represent all reported planet-hosting stars to date. The two components of each binary are connected with solid and dotted lines. -- astro-ph.SR

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

Chemical Signatures Of Planetary Systems In Their Host Stars. Near-infrared Spectroscopy Of Four Planet-hosting Wide Binaries

by Keith CowingMay 14, 2026May 14, 2026

An important open question in exoplanet studies is whether planets leave detectable chemical fingerprints on their host stars. While several studies have suggested possible planetary chemical signatures in planet-hosting stars, […]

Probability of a planet with initial semi major axis a0 remaining bound to its host star after the birth cluster dissolves as a function of absolute value of the angular separation |∆ϕ| from the centre of the stream. Contours of Psurvive are determined after applying a multidimensional Gaussian filter to the dataset with a standard deviation of 1. Stars close to the centre of the stream are less likely to host planets at any a0, with outer planets more likely to be stripped from their host star than inner planet. Stars near the edges of the stream are more likely to retain planets out to 2000 au. -- astro-ph.EP

AI - Data - Apps - Cybernetics, Exoplanets, -moons, -comets, Status Report, Stellar Cartography

Life Is But a Stream: The Distribution Of Planetary Systems Along Stellar Streams And Their Properties

by Keith CowingMay 11, 2026May 11, 2026

The majority of discovered exoplanets have been observed orbiting field stars as opposed to within a star cluster. To determine whether the lack of observed exoplanets in star clusters is […]

This image shows the MINERVA-Australis array located at the Mount Kent Observatory in Australia. -- NASA

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

Finding Alien Worlds in Queensland — A Decade of MINERVA-Australis

by Keith CowingMay 9, 2026May 9, 2026

Three decades ago, humanity entered the Exoplanet Era, with the discovery of the first planets orbiting other stars. Today, more than 6000 exoplanets are known – a tally recently bolstered […]

Astrochemistry, Astronomy & Telescopes, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report, Stellar Cartography

Overview Of The New Hubble Spectroscopic Legacy Archive

by Keith CowingMay 8, 2026May 8, 2026

The new Hubble Spectroscopic Legacy Archive (HSLA) provides coadded spectra of individual targets that have been observed with the Cosmic Origins Spectrograph (COS) and the Space Telescope Imaging Spectrograph (STIS) […]

The figure reports two of the PSFs used to simulate FGS1 (left) and AIRS-CH0 (right). The PSFs are sampled at the sub-pixel level and reported in decibels normalised to the maximum value in the field. The axes report the grid into pixel and micron units. The reader may note that the FGS1 PSF is highly aberrated and complex, so it is sampled on a grid of the same size as the detector (32 × 32), while the AIRS-CH0 PSF is an Airy function and here is reported on a smaller grid. For details, please refer to the software documentation. -- astro-ph.EP

AI - Data - Apps - Cybernetics, Ariel Mission, Astronomy & Telescopes, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report, Stellar Cartography

A Public Dataset Of Ariel Simulated Observations For Developing Exoplanetary Atmosphere Data Reduction Pipelines

by Keith CowingMay 7, 2026May 7, 2026

Detecting and characterising exoplanet atmospheres remains challenging because atmospheric signals can be comparable to residual noise and instrumental/astrophysical systematics. Spectral features span from a few ppm for small planets up […]

Stellar Cartography

Astrometric Exoplanet Detection Survives Solar-like Stellar Contamination

Planetary Formation Tracks On The Hertzsprung-Russell Diagram: Visualising The Processes Of Giant Planet Growth

A Uniform Determination Of The Bulk Metallicities And Alpha Enrichments Of Confirmed Exoplanet Systems With TRES

Ariel Stellar Characterisation IV. Fundamental Parameters Of 18 Hot Stars In The Ariel Mission Candidate Sample

The HAges Catalog: Stellar Ages For High Priority HWO Target Stars

Chemical Signatures Of Planetary Systems In Their Host Stars. Near-infrared Spectroscopy Of Four Planet-hosting Wide Binaries

Life Is But a Stream: The Distribution Of Planetary Systems Along Stellar Streams And Their Properties

Finding Alien Worlds in Queensland — A Decade of MINERVA-Australis

Overview Of The New Hubble Spectroscopic Legacy Archive

A Public Dataset Of Ariel Simulated Observations For Developing Exoplanetary Atmosphere Data Reduction Pipelines

A Martian Horizon Last Monday Afternoon

Habitable-zone Earths At The Detection Frontier: Measured Completeness And False-alarm Rate Of A Transit Pipeline For The PLATO M-dwarf Sample

A Homogeneous Survey Of JWST MIRI Transmission Spectra Of 10 Exoplanets

Retrieving Ocean Glint Reflectance Signatures From Directly Imaged Earth-like Exoplanets

Analytical Platform (Microsampling, Catapulting, Trapping, and LIBS) for the Characterization of Discrete Domains in Samples of Astrochemical Interest