K-dwarf stars are promising targets in the exploration of potentially habitable planets. Their properties, falling between G and M dwarfs, provide an optimal trade-off between the prospect of habitability and […]
CARMENES
Posted inAlpha Centauri, Astronomy & Telescopes, Barnard's Star, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Status Report
A Sub-Earth-mass Planet Orbiting Barnard’s Star
Barnard’s star is a primary target within the ESPRESSO guaranteed time observations (GTO) as it is the second closest neighbour to our Sun after the α Centauri stellar system.
Posted inAstronomy & Telescopes, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Status Report, Water/Hycean Worlds & Oceanography
RedDots: Limits on Habitable and Undetected Planets Orbiting Nearby Stars GJ 832, GJ 674, and Ross 128
Aims. Using HARPS spectroscopic data obtained by the RedDots campaign, as well as archival data from HARPS and CARMENES, supplemented with ASH2 and T90 photometry, we aim to search for […]
Posted inAstrogeology, Astronomy & Telescopes, Exoplanets, -moons, -comets, Gaia - Planetary Perspectives, Habitable Zones, Status Report
An Earth-sized Planet On The Verge Of Tidal Disruption
TOI-6255~b (GJ 4256) is an Earth-sized planet (1.079±0.065 R⊕) with an orbital period of only 5.7 hours. With the newly commissioned Keck Planet Finder (KPF) and CARMENES spectrographs, we determined […]
![LEFT: M dwarf abundance distributions for Mg and Si separated according to the kinematic membership of stars in the thick disc (TD), thick disc-thin disc transition (TD-D), thin disc (D), and young disc (YD), following the criteria of Montes et al. (2018) (see text for details). Mean values for each population are indicated by vertical lines. RIGHT: Top panel: [Si/Fe] vs. firon. The target stars are in orange while the black points correspond to the firon values computed from the Adibekyan et al. (2012) abundances. The fit through the M dwarf values is denoted with a blue line. Bottom panel: Histogram for the firon values of our sample. -- astro-ph.SR](https://i0.wp.com/astrobiology.com/wp-content/uploads/2024/07/The-CARMENES-Search-For-Exoplanets-AroundM.png?resize=1200%2C716&ssl=1)
Posted inAstrochemistry, Astrogeology, Astronomy & Telescopes, Imaging & Spectroscopy, Status Report
The CARMENES Search For Exoplanets Around M Dwarfs: Magnesium And Silicon Abundances Of K7-M5.5 Stars
We present the abundances of magnesium (Mg) and silicon (Si) for 314 dwarf stars with spectral types in the interval K7.0-M5.5 (Teff range ~4200-3050 K) observed with the CARMENES high-resolution […]
Posted inAstronomy & Telescopes, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report
The CARMENES Search for Exoplanets Around M Dwarfs. Revisiting the GJ 581 Multi-planetary System with New Doppler Measurements from CARMENES, HARPS, and HIRES
GJ 581 is a nearby M dwarf known to host a packed multiple planet system with 2 super-Earths and a Neptune-mass planet. We present new orbital analyses of the system, […]
Posted inAstronomy & Telescopes, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report
TOI-1685 b is a Hot Rocky Super-Earth: Updates to the Stellar and Planet Parameters of a Popular JWST Cycle 2 Target
We present an updated characterization of the TOI-1685 planetary system, which consists of a Pb = 0.69 day USP super-Earth planet orbiting a nearby (d = 37.6 pc) M2.5V star […]
Posted inAstronomy & Telescopes, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Status Report
Gliese 12 b: A Temperate Earth-sized Planet at 12 pc Ideal for Atmospheric Transmission Spectroscopy
Recent discoveries of Earth-sized planets transiting nearby M dwarfs have made it possible to characterize the atmospheres of terrestrial planets via follow-up spectroscopic observations.
![Analysis of the stellar parameters derived with our methodology. The dots are colour-coded according to the estimated metallicity. The size of the dots is proportional to the estimated projected rotational velocity. The top left panel shows a Kiel diagram, with the red, black, and blue dashed lines corresponding to 5 Gyr PARSEC isochrones with [M/H] = −0.4, 0.0 and 0.1 dex, respectively. Empty squares represent the stars reported to have a behaviour akin to subdwarfs both in Mar21 and Schw19 (same for bottom left panel). Top right: black and grey dashed lines correspond to solar metallicity PARSEC isochrones for 5 and 0.1 Gyr, respectively. Black and grey dotted lines correspond to solar metallicity Baraffe et al. (2015) isochrones for 5 and 0.1 Gyr, respectively. Bottom left: triangles represent stars identified as Hα active in Schöfer et al. (2019). Empty stars depict members of the thick disc Galactic population (Cortés-Contreras et al., in prep.). Bottom right: plus symbols correspond to stars identified as members of the young disc Galactic population by Cortés-Contreras et al. (in prep.). Empty circles represent stars with a possible membership in a young stellar associaton, as explained in Section 4.1. -- astro-ph.SR](https://i0.wp.com/astrobiology.com/wp-content/uploads/2024/05/Using-Autoencoders-And-Deep.png?resize=1200%2C717&ssl=1)
Posted inAI - Data - Apps - Cybernetics, Astronomy & Telescopes, Imaging & Spectroscopy, Status Report, Stellar Cartography
Using Autoencoders And Deep Transfer Learning To Determine The Stellar Parameters Of 286 CARMENES M Dwarfs
Deep learning (DL) techniques are a promising approach among the set of methods used in the ever-challenging determination of stellar parameters in M dwarfs.
Posted inAstrochemistry, Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report
Revealing H2O Dissociation In WASP-76~b Through Combined High- and Low-resolution Transmission Spectroscopy
Numerous chemical constraints have been possible for exoplanetary atmospheres thanks to high-resolution spectroscopy (HRS) from ground-based facilities as well as low-resolution spectroscopy (LRS) from space.