carbon-rich Asymptotic Giant Branch (AGB) stars Archives

Left: Gas-phase abundances of aromatic molecules versus distance from the star calculated with CTM (solid lines) and without it (dotted lines). Right: Gas-phase abundances of aromatic molecules at R = 2.7 R⋆. The red color indicates the model with CTM. The blue color shows the model without it. -- astro-ph.GA

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Imaging & Spectroscopy, Interstellar, Status Report

The Impact Of Surface Acetylene Cyclotrimerization On The Abundance Of Aromatic Hydrocarbons In Carbon-rich Asymptotic Giant Branch Stars

by Keith CowingDecember 10, 2025December 10, 2025

This work investigates the catalytic role of dust grains in forming aromatic hydrocarbons via acetylene cyclotrimerization on their surfaces within the circumstellar envelopes of carbon-rich asymptotic giant branch (AGB) stars.

Top panels: Moment 0 map of the CCS (JN = 43 − 32) line overlaid by black contours indicating moment 0 map of the HC3N (J = 5 − 4) line. These data were obtained with the Nobeyama 45m radio telescope (beam size=3700 at 45 GHz). The original data were provided by Dr. Fumitaka Nakamura (NAOJ) and Dr. GOTHAM and QUIJOTE projects. The spectral figures are from McGuire et al. (2020) and Cernicharo et al. (2021b). Kazuhito Dobashi (Tokyo Gakugei University). The magenta cross shows the position of the Cyanopolyyne Peak (CP) observed by the two line survey projects. -- astro-ph.GA

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

Carbon-Chain Chemistry in the Interstellar Medium

by Keith CowingMarch 28, 2023March 28, 2023

The presence of carbon-chain molecules in the interstellar medium (ISM) has been known since the early 1970s and >100 such species have been identified to date, making up >40% of […]

carbon-rich Asymptotic Giant Branch (AGB) stars

The Impact Of Surface Acetylene Cyclotrimerization On The Abundance Of Aromatic Hydrocarbons In Carbon-rich Asymptotic Giant Branch Stars

Carbon-Chain Chemistry in the Interstellar Medium

Sea Ice As An Origin Of Life Location For Hycean And Ocean Worlds

Viruses, Proviruses and Satellites from Asgard Archaea Enrichments Reveal Complex Microbial Interactions

Mars Rover Curiosity’s Hand Lens Imager (MAHLI) Calibration

Carbon and Sulfur Isotopes of Microfossils and Pyrites from Neoarchean Cherts: Microbial Diversity in an Ancient Deep-Marine Environment

Auroral Belts As Magnetically Localized Reactors For Prebiotic Chemistry On Early Earth