![Example fits to the observed spectrum of GJ 436 (Teff = 3495 K, [Fe/H] = -0.05 dex, 2023 observation), LHS 1140 (Teff = 3111 K, [Fe/H] = –0.07 dex), and TOI 2290 (Teff = 3758 K, [Fe/H] = –0.18 dex) are shown as solid purple, gold, and cyan points, respectively. GJ 436 and LHS 1140 spectra were obtained with IGRINS while the TOI 2290 spectrum was obtained with NIRSPEC. The FeH line falls in an order gap for our NIRSPEC spectra and is not shown in this figure. Best fitting synthetic spectra are shown as dashed lines. Synthetic spectra creation and fitting methodology is described in section 3.-- [astro-ph.SR]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/11/The-Composition.png?resize=1200%2C752&ssl=1)
[astro-ph.SR] Determining M-dwarf abundances is an important step to discerning the chemical evolution of the Milky Way and characterizing exoplanetary systems, especially since these objects commonly host small exoplanets.
Spectroscopy
Posted inExoplanets, -moons, -comets
An Analytical Framework for Atmospheric Tides on Rocky Planets. II. Semidiurnal Thermotidal Torque
[astro-ph.EP] The thermodynamic acceleration induced by atmospheric thermal tides has a major impact on the rotation of temperate rocky planets, where gravitational and radiative tidal forcings are of comparable strength.
Posted inExoplanets, -moons, -comets
BeAR: The Bern Atmospheric Retrieval code – A GPU-accelerated Framework for Low-resolution, High-resolution, and Joint Retrievals of Exoplanet Atmospheres
[astro-ph.EP] We present BeAR, the Bern Atmospheric Retrieval code and successor of Helios-r, and its new high-resolution cross-correlation framework for emission and transmission spectra.
![Conceptual relation between cometary dust activity and the release of refractory organic material.-- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/11/Cometary-dust.png?resize=1200%2C716&ssl=1)
Posted inComets and Asteroids
Cometary Dust Activity As A Proxy For Refractory Organic Material Release
[astro-ph.EP] Cometary dust is an important reservoir of refractory organic matter and may contribute to the redistribution of carbon-rich material throughout planetary systems.
![The habitable-zone correction at a glance. Each symbol is a TOI placed at a distance from the centre that scales with its insolation relative to the conservative habitable zone of its host (green ring; hotter planets inside, colder outside); symbol size scales with planet radius. Left: positions from the catalogue periods, which place 28 duo-transits in the conservative habitable zone. Right: positions from the periods of this work. Of the 28, nine are resolved and only two remain in the habitable zone, both giants (TOI-4600 c and TOI-1894.01); the 19 unresolved objects, drawn with opacity proportional to their probability of lying in the habitable zone, are expected to contribute 0.0–0.1. Two planets enter the habitable zone: TOI-6478 b, a duo-transit catalogued outside it, and TOI-2298 b, a mono-transit with no catalogue period. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/11/Are-habitable.png?resize=1200%2C720&ssl=1)
Posted inHabitable Zones
Are Habitable-zone TESS Objects of Interest really there? Period Resolution From The Full Archive
[astro-ph.EP]. TESS Objects of Interest (TOIs) seen as single or duo transits carry a catalogue period that is undefined or equal to the separation of the two events, and their […]
Posted inExoplanets, -moons, -comets
On The Detectability of Compact Multi-Planet Systems via Gravitational Microlensing
[astro-ph.EP] Compact multi-planet systems orbiting ultracool dwarfs, such as TRAPPIST-1, may be a major population of terrestrial worlds with poorly constrained demographics.
![Bolometric intensity map (right) from the M dwarf simulation of Table 1. The sketch on the left shows the approximate size of the numerical box with respect to the stellar radius, assuming a (R=0.4 R⊙ for a 3500K M dwarf star, Parsons et al. 2018). -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/11/The-impact.png?resize=1200%2C718&ssl=1)
Posted inExoplanets, -moons, -comets
The Impact of M Dwarf Stellar Convection on Exoplanetary Atmospheric Signatures. A 3D Radiation-hydrodynamics Simulation Analysis for High-resolution Spectroscopy
[astro-ph.EP] M dwarf stars represent prime targets for the detection and characterization of small, temperate exoplanets; however, their complex activity and convective surfaces pose significant challenges for high-resolution spectroscopic studies.
Posted inMars
ExoMars Trace Gas Orbiter Detects Hints Of Volcanic Activity On Mars
[ESA] New evidence from gas seeping above volcanic rifts suggests Mars is not geologically dead deep inside, but merely sleeping.
Posted inBiosignatures & Paleobiology
Direct Analysis in Real Time Mass Spectrometry (DART-MS) Study of Amino Acids in the Vacuum Stable Liquids EMI-BF4, EMI-Acetate, DEMA-OTf, DEMA-MsO, and Glycerol
[physics.app-ph] The detection of organics and potential biomolecules is an important goal of planetary science and astrobiology spacecraft missions, and many types of analytical chemistry for studying organics depend upon […]
Posted inTricorders & Sensors
All-Laser Suite Analytical Platform (Microsampling, Catapulting, Trapping, and LIBS) for the Characterization of Discrete Domains in Samples of Astrochemical Interest
[Analytical Chemistry via PubMed] The chemical characterization of scarce or heterogeneous solid samples remains a significant analytical challenge due to the high material quantities required by conventional techniques.