TW Hya Archives - Astrobiology

Spectrally integrated line flux maps for 3I/ATLAS observed using JWST NIRSpec: (a) H2O at 2.7 µm, (b) CO2 at 4.3 µm, (c) CO at 4.7 µm. Image axes are aligned with the equatorial (RA/decl.) grid. Molecular emission has been isolated by subtracting a polynomial fit to the adjacent continuum. Spatial coordinates are with respect to the brightest pixel in each map (the pseudo-nucleus). Inset panels (upper right) show the continuum-subtracted spectra within the image integration wavelength range, spatially integrated within a 3′′ diameter circular aperture centered on the pseudo-nucleus (corresponding to 3,900 km at the 1.8 au distance of the comet from the telescope). Lower left corner shows the direction of the (sky-projected) comet-Sun (S) and nucleus velocity (v) vectors. -- astro-ph.EP

Astrochemistry, Astrogeology, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Comets and Asteroids, Icy Worlds, Imaging & Spectroscopy, Interstellar, Status Report

Isotopic Evidence For A Cold And Distant Origin Of The Interstellar Object 3I/ATLAS

by Keith CowingMarch 17, 2026March 17, 2026

Interstellar objects provide the only directly observable samples of icy planetesimals formed around other stars, and can therefore provide insight into the diversity of physical and chemical conditions occurring during […]

Disk physical structure from our three parametric models (Models 1 to 3 from top to bottom, see Tables 1 and 2). The 2D gas temperature (left) and total H density (right) are shown as colors, with iso-curves in white. The dashed red line corresponds to AV = 1 mag (as measured from the top). -- astro-ph.EP

Astrochemistry, Astrogeology, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Interstellar, Status Report

Ortho-Para Chemistry of H2CO in the Protoplanetary Disk TW Hya

by Keith CowingMarch 17, 2026March 17, 2026

The spatial distribution of the chemical reservoirs in protoplanetary disks is key to elucidate the composition of planets, especially habitable ones. However, the partitioning of the main elements among the […]

Astrochemistry, Astrogeology, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Status Report

Radial and Vertical Constraints On The Icy Origin Of H2CO In The HD 163296 Protoplanetary Disk

by Keith CowingApril 10, 2024April 10, 2024

H2CO is a small organic molecule widely detected in protoplanetary disks. As a precursor to grain-surface formation of CH3OH, H2CO is considered an important precursor of O-bearing organic molecules that […]

Physical parameters. gas number density (ngas), UV flux (FUV), Ionization rates (X ray + Cosmic ray,ζ), and dust temperature (Tdust). -- astro-ph.GA

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Exoplanets, -moons, -comets, Status Report

Carbon Isotope Chemistry In Protoplanetary Disks: Effects Of C/O Ratios

by Keith CowingApril 3, 2024April 3, 2024

Carbon isotope fractionation of CO has been reported in the disk around TW Hya, where elemental carbon is more abundant than elemental oxygen ([C/O]elem> 1).

Astrochemistry, Astrogeology, Exoplanets, -moons, -comets, Status Report

The Carbon Isotopic Ratio And Planet Formation

by Keith CowingMarch 19, 2024March 19, 2024

We present the first detection of 13CCH in a protoplanetary disk (TW Hya). Using observations of C2H we measure CCH/13CCH = 65 +/- 20 in gas with a CO isotopic […]

Moment zero maps of the three brightest 13CN lines and the stacked moment zero maps of the three lines. The white dotted contours represent the 217 GHz continuum emission, starting at the brightness temperature of 1K and drawn every 3K. The synthesized beam is shown in the lower-left corner of each panel.-- astro-ph.EP

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Imaging & Spectroscopy, Status Report

The First Spatially-resolved Detection of 13CN in a Protoplanetary Disk and Evidence for Complex Carbon Isotope Fractionation

by Keith CowingMarch 5, 2024March 5, 2024

Recent measurements of carbon isotope ratios in both protoplanetary disks and exoplanet atmospheres have suggested a possible transfer of significant carbon isotope fractionation from disks to planets.