host star Archives - Astrobiology

Kiel diagram for 290 stars with 5000 K ≤ Teff ≤ 6500 K and log g ≥ 4.0 dex analyzed in this work. The dashed black lines present the solar values obtained for the Ceres 2009-02-08 solar spectrum, Teff = 5759±18 K, log g = 4.43±0.05 dex and [Fe/H] = 0.00±0.01 dex. -- astro-ph.EP

Chemical Abundances of the Bioessential Elements C, O and S, and the Refractory Elements

by Keith CowingJuly 3, 2026July 3, 2026

[astro-ph.EP] We determined atmospheric and evolutionary parameters, along with chemical abundances of C, O, S, Fe, and Ni for 290 solar-type exoplanet hosting stars using high-resolution HARPS-North and HARPS-South spectra, […]

Simulated stellar wind of TOI-1860, DS Tuc A, and HD 63433 in the x⋆ −y⋆ plane. The rotation axis lies along the positive z⋆. The Alfvén surface is shown as a translucent surface and its intersection on the x⋆ −y⋆ plane is shown as a white curve. The colour bar indicates the total wind velocity. The orbits of the hosted exoplanets are also included as coloured ellipses. For HD 63433, we also show the simulations from the 2023 data analysed in Bellotti et al. (2024). -- astro-ph.SR

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

Spectropolarimetric Characterisation Of Exoplanet Host Stars In Preparation Of The Ariel Mission II. The magnetised wind environment of TOI-1860, DS Tuc A, and HD 63433

by Keith CowingDecember 27, 2025December 27, 2025

We update the status of the spectropolarimetric campaign dedicated to characterise the magnetic field properties of a sample of known exoplanet-hosting stars included in the current target list of the […]

Refractory ratio of stars compared to their exoplanets as populations. The host stars population is shown in red at contours of 1 and 2 σ values, while the dotted contour corresponds to the GALAH stellar population. The marginal distribution of Fe/Mg and Fe/Si are shown outside of the scatter plot for stars (red), all exoplanets (blue) and GALAH (dotted) populations. Exoplanets above the RTR, which require volatiles, are indicated as white circles and solar system objects are shown in yellow. Notice the axes are in logarithmic scale. -- astro-ph.EP

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

Evidence Of 1:1 Slope Between Rocky Super-Earths And Their Host Stars

by Keith CowingDecember 1, 2025December 1, 2025

The relationship between the composition of rocky exoplanets and their host stars is fundamental to understanding planetary formation and evolution.

Effect of relative luminosity, S/S⊕, on simulated steady-state atmospheres (pCO2 , temperature). A Terrestrial exoplanets in the mobile-lid (ML) interior convection regime. B Terrestrial exoplanets in the stagnant-lid (SL) regime. C,D Distributions of simulations across a discretized range of S/S⊕. -- astro-ph.EP

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gaia - Planetary Perspectives, Habitable Zones, Imaging & Spectroscopy, Mars, Press Release, Venus, Water/Hycean Worlds & Oceanography

Interior Convection Regime, Host Star Luminosity, And Predicted Atmospheric CO2 Abundance In Terrestrial Exoplanets

by Keith CowingJune 26, 2024June 26, 2024

Terrestrial planets in the Habitable Zone of Sun-like stars are priority targets for detection and observation by the next generation of powerful space telescopes.

This infographic compares the characteristics of three classes of stars in our galaxy: Sunlike stars are classified as G-type stars; stars less massive and cooler than our Sun are K dwarfs; and even fainter and cooler stars are the reddish M dwarfs. The habitable zones, potentially capable of hosting life-bearing planets, are wider for hotter stars. The longevity for red dwarf M stars can exceed 100 billion years. K dwarf ages can range from 15 to 45 billion years. Meanwhile, our Sun only lasts for 10 billion years. The relative amount of harmful radiation (to life as we know it) that stars emit can be 80 to 500 times more intense for M dwarfs relative to our Sun, but only 5 to 25 times more intense for the orange K dwarfs. Red dwarfs make up the bulk of the Milky Way's population, about 73%. Sunlike stars are merely 6% of the population, and K dwarfs are at 13%.-- NASA, ESA and Z. Levy (STScI)

AI - Data - Apps - Cybernetics, Astrochemistry, Astronomy & Telescopes, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Nomenclature, Systematics, Natural History, Status Report, Stellar Cartography

Exoplanet Host Star Classification: Multi-Objective Optimisation Of Incomplete Stellar Abundance Data

by Keith CowingJune 25, 2024June 25, 2024

The presence of a planetary companion around its host star has been repeatedly linked with stellar properties, affecting the likelihood of sub-stellar object formation and stability in the protoplanetary disc, […]

The variable stars with known exoplanets colored by the detection method of their planets. The starred points are the locations of the unique cases KELT-9 (A), PDS 70 (B), and HD 106270 (C). -- astro-ph.EP

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

Variability of Known Exoplanet Host Stars Observed by TESS

by Keith CowingMay 17, 2023May 17, 2023

Both direct and indirect methods of exoplanet detection rely upon detailed knowledge of the potential host stars. Such stellar characterization allows for accurate extraction of planetary properties, as well as […]