[astro-ph.GA] The aromatic infrared bands (AIBs), emission features observed ubiquitously across a wide variety of interstellar objects, are commonly attributed to radiative cooling of highly-excited ground-state vibrational levels of polycyclic […]
Interstellar
![Images acquired on 2019 October 4 (left) and 27 (right) with LDT. The top row show stacks of r and CN images, respectively. The bottom row shows the same images enhanced by subtraction of an azimuthal median profile. The enhanced CN images have been smoothed with a Gaussian profile to better reveal the faint underlying structure. A compass indicating north (N), east (E), the anti-sunward direction (−⊙), and the anti-velocity vector (−v) are overlaid on the r panels, while a scale bar showing a distance at the comet of 20,000 km is given on the CN panels (1 arcsec corresponds to 2134 km on October 4 and 1814 km on October 27). All four panels for a given night have the same orientation and physical scale at the comet. The October 4 image is a single frame and shows several artifacts that could not be removed without a median combination include several bright pixels in the CN frame (yellow) and a bad column in all frames (black diagonal line). On October 4, a bright star is seen near the left edge of the r frames and as a diagonal (yellow) line in the upper right in CN. Two faint trailed stars are visible in the r images on October 27. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/The-Highly.png?resize=1200%2C720&ssl=1)
Posted inComets and Asteroids
The Highly Unusual Behavior And Chemical Composition Of Interstellar Comet 2I/Borisov
[astro-ph.EP]. We report on imaging, spectroscopy, and narrowband photometry of interstellar comet 2I/Borisov obtained at Lowell Observatory from 2019 September 13 to December 16.
Posted inAstrochemistry
Slow-electron-triggered Chemistry In Interstellar Methanol-water Ices
[Astronomy & Astrophysics] Water and, to a lesser extent, methanol are widespread in interstellar space as ices, where sustained exposure to ionizing radiation promotes the formation of complex compounds such […]
![LOCO-CV predicted vs DFT binding energies for 13 adsorbate species on ASW12 clusters. Each point represents a single adsorbate–surface configuration, coloured by species identity; asterisks denote radical species. Pooled metrics across all leave-one-cluster-out folds: R2 = 0.896, RMSE = 574 K, MAE = 378 K. -- [astro-ph.GA]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/AstroBind.png?resize=1200%2C715&ssl=1)
Posted inAstrochemistry
AstroBind: Machine Learning Prediction Of Binding Energy Distributions On Interstellar Water Ice From Geometric Surface Descriptors
[astro-ph.GA] Binding energies on amorphous solid water regulate molecular desorption in molecular clouds and protoplanetary disks, but computing them from first principles across the heterogeneous binding sites of disordered ice […]
Posted inExoplanets, -moons, -comets
ADORA: A Differentiable Optical Modeling And Astrometric Retrieval Framework For SHERA
[astro-ph.EP] Motivated by recent observations suggesting rings found in debris disks are wider than those in protoplanetary disks, we consider a picture in which planetesimals formed in radially narrow dust […]
![The timescale required for a 10 M⊕ring of planetesimals around a 1 M⊙ star to radially diffuse 0.1 M⊕ into the inner 0.5 au. The planetesimal density is assumed to be 4 g cm−3 . The black dashed line shows the boundary where the inner edge is just reachable by the radially diffusing disk, below which the escape velocity is less than the critical escape velocity (v0.5au) and planetesimals are not deliverable at this level. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/Substructure.png?resize=1200%2C715&ssl=1)
Posted inExoplanets, -moons, -comets
Substructure Evolution From Protoplanetary To Debris Disks Driven By Mutually Gravitating Planetesimals And Implications On Kepler Resonances And Free-floating Planets
[astro-ph.EP]. Motivated by recent observations suggesting rings found in debris disks are wider than those in protoplanetary disks, we consider a picture in which planetesimals formed in radially narrow dust […]
![Example of the stacking procedure for the Maidanak data obtained on 2025 August 15, based on ten 60 s exposures in each of the B, V , and R filters. Left: Comet-centered stack, showing the coma morphology without trailing of the comet signal. The pink circle indicates an aperture radius of 10 000 km. Right: Sidereal stack used for photometric calibration, in which the comet appears trailed.-- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/The-Inbound.png?resize=1200%2C720&ssl=1)
Posted inComets and Asteroids
The Inbound Gas and Dust Evolution of Interstellar Comet 3I/ATLAS from Optical Spectroscopy and Multi-band Photometry
[astro-ph.EP] Interstellar objects (ISOs) provide direct constraints on the composition and evolution of extrasolar planetary systems. As the third confirmed ISO, comet 3I/ATLAS offers a rare opportunity to study pristine […]
![Schematic of generative process to determine most chemically relevant molecular candidates for the unassigned spectroscopic transitions.-- [astro-ph.GA]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/Automated.png?resize=1200%2C711&ssl=1)
Posted inAstrochemistry
Automated Assignment and Prediction of Molecules in Astronomical Line Surveys Using Machine-Learning-Based Chemical Embeddings
[astro-ph.GA] Modern radio telescopes generate vast amounts of observational data, offering valuable insights into the molecular composition of interstellar sources. Identifying the molecules within these datasets typically involves time-consuming and […]
Posted inAstrochemistry
Catalytic Formation of H2 On Carbonaceous Dust Grains – Implications For Interstellar Observations
[astro-ph.GA] We use kinetic Monte Carlo (KMC) simulations to study molecular hydrogen formation on carbonaceous dust grain surfaces, validated against recent laboratory measurements of H2 formation on coronene films at […]
Posted inAstrochemistry
The Galactic Centre G+0.633-0.0604 Molecular Cloud: A New Gold Mine for Astrochemistry
[astro-ph.GA] Astrochemistry is living a golden age, with more than a quarter of the ~350 molecules in the current interstellar census having been detected over the last three years. One […]