very low-mass stars Archives

Detections and non-detections of pure rotational line emission of water. The continuum subtracted spectra are shown in black and the water slab models in blue. The slab model parameters are arbitrarily chosen for a visual match with the observed spectra. The temperature and column densities of the models are the same across all the panels, while the emitting area is scaled to match the flux level. The vertical gray area in each panel shows the wavelength region used to calculate the noise level. The light gray shaded region across the spectra shows the ±3σ noise level obtained in this way. The identified water line transitions are indicated at the top of the figure as JKa Kc − J ′ K ′ a K ′ c , where J, Ka, Kc are the total angular momentum quantum number, and the projections of the angular momentum on the principal axes. -- astro-ph.EP

Astrochemistry, Astronomy & Telescopes, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Brown Dwarfs, Imaging & Spectroscopy, Status Report

MINDS: The Very Low-mass Star And Brown Dwarf Sample — Hidden Water In Carbon-dominated Protoplanetary Disks

by Keith CowingApril 16, 2025April 16, 2025

Infrared observations of the inner disks around very low-mass stars (VLMS, <0.3M⊙) have revealed a carbon-rich gas composition in the terrestrial planet-forming regions. Contrary to the typically water-rich T Tauri […]

Observed UCD candidates on a zoomed Gaia MG - G − J and G − GRP diagrams: UCDs are coloured by their obtained spectral type, as explained in Sect. 3. The two circled UCDs have peculiar colours (see text). Subdwarfs candidates are represented by crosses (see Sect. 4.1). Peculiar objects are represented by triangles (Sect. 4.2). The UCDs with common parallaxes and proper motions with another system are represented by diamonds (see Sect. 4.3) and those in (potentially) unresolved binary systems by squares (Sect. 4.4). The grey points are the sources from the Gaia Catalogue of Nearby Stars, with a RUWE < 1.4. The insets illustrate the locus of our sample on entire GaiaCatalogue of Nearby stars colour-absolute magnitude diagrams. -- astro-ph.SR

Astronomy & Telescopes, Brown Dwarfs, Exoplanets, -moons, -comets, Gas Giants, Imaging & Spectroscopy, Status Report, Stellar Cartography

Near-infrared Spectroscopic Characterisation Of Gaia Ultra-cool Dwarf Candidates; Spectral Types And Peculiarities

by Keith CowingFebruary 16, 2024February 16, 2024

Context: The local census of very low-mass stars and brown dwarfs is crucial to improving our understanding of the stellar-substellar transition and their formation history. These objects, known as ultra-cool […]

very low-mass stars

MINDS: The Very Low-mass Star And Brown Dwarf Sample — Hidden Water In Carbon-dominated Protoplanetary Disks

Near-infrared Spectroscopic Characterisation Of Gaia Ultra-cool Dwarf Candidates; Spectral Types And Peculiarities

Opportunity to Contribute to NASA DARES Community White Paper on Phototrophic Biosignatures

NASA Establishes Mars Forward Operational Risk and Contamination Evaluation (M-FORCE) Tiger Team to Shape Mars Planetary Protection Protocols

Miraflores Butte On Mars

Ocean World Exploration: 2026 American Samoa ROV + Mapping Exploration

Development Of An Adaptive Optics Testbed At MPIA For The ELT/Planetary Camera And Spectrograph (PCS)