Results 41 to 50 of about 239,951 (165)

Coagulation–Fragmentation Equilibrium for Charged Dust: Abundance of Submicron Grains Increases Dramatically in Protoplanetary Disks

open access: yesThe Astrophysical Journal, 2023
Dust coagulation in protoplanetary disks is not straightforward and is subject to several slowdown mechanisms, such as bouncing, fragmentation, and radial drift to the star.
Vitaly Akimkin   +4 more
doaj   +1 more source

A Coronagraphic Pilot Study of the Circumstellar Environments around Red Supergiants: CD -31°4916’s Dust Morphology

open access: yesThe Astronomical Journal
Many mechanisms have been proposed to contribute to massive-star mass loss, but in general little is known about the physics involved. Studies of circumstellar environments around massive stars might help to determine which mechanisms are the most common.
Jamie R. Lomax   +3 more
doaj   +1 more source

Confined Chemistry in Space: Zeolite‐Supported Fe13 Nanoclusters Modulate CS Reactivity

open access: yesSmall Structures, Volume 7, Issue 3, March 2026.
The study explores how an Fe13 cluster confined in chabazite reshapes the reaction of CS and H2 under astrochemical conditions. Confinement promotes C–S bond cleavage over hydrogenation, directing chemistry toward CH4 and H2S formation. Additional CS enables CS2 and C2 species. Microkinetic analysis identifies protoplanetary environments where zeolites
Gerard Pareras, Albert Rimola
wiley   +1 more source

Circumstellar dust emission models

open access: yesThe Astrophysical Journal, 1994
We present the wavelength-dependent absorption coefficient K(sub lambda) the scattering coefficient o(sub lambda), the albedo w(sub lambda), and the average cosine of the scattering phase function g(sub lambda) between 0.0912 micrometers and 1000 micrometers for four interstellar medium grain models.
Mark G. Wolfire, Ed Churchwell
openaire   +1 more source

Satellites and Small Bodies With ALMA: Insights Into Solar System Formation and Evolution

open access: yesAGU Advances, Volume 6, Issue 6, December 2025.
Abstract Our understanding of the formation and evolution of planetary systems has made major advances in the past decade. This progress has been driven in large part by the Atacama Large Millimeter/submillimeter Array (ALMA), which has given us an unprecedented view of solar system bodies themselves, and of the structure and chemistry of forming ...
Katherine de Kleer   +3 more
wiley   +1 more source

Clusters Stagnating During Condensation: Metastable Material or a Separate State of Matter?

open access: yesAnnalen der Physik, Volume 537, Issue 10, October 2025.
Condensation stagnation, that is, the existence of a delay between nucleation and growth during the gas‐phase particle formation, is a crucial phenomenon, which manifests itself as the presence of supercritical clusters in resulting particulates. The light emission signature of stagnant clusters is identified in the magnesium particle flame in air, and,
Nicholas R. Jaramillo   +4 more
wiley   +1 more source

Near-infrared Integral-field Spectroscopy of the Wind Forming Region of CW Leo

open access: yesThe Astronomical Journal
The circumstellar envelope of the carbon star CW Leo exhibited various unexpected changes in recent optical imaging observations. We have performed a follow-up observation using the Near-infrared Integral-Field Spectrograph (NIFS) equipped on the Gemini ...
Hyosun Kim   +3 more
doaj   +1 more source

Characteristics of Interstellar and Circumstellar Dust [PDF]

open access: yesInternational Astronomical Union Colloquium, 1991
Abstract: This paper reviews our current knowledge of interstellar and circumstellar dust from an observational point of view. It is concluded that interstellar dust is highly heterogenous. It consist of a large number of different materials formed in a great variety of stellar birthsites under varying conditions and each with a highly isotopically ...
openaire   +1 more source

Is Phenylnitrene a Missing Link in the Formation of Polycyclic Aromatic Nitrogen Heterocycles?

open access: yesAngewandte Chemie International Edition, Volume 64, Issue 31, July 28, 2025.
A new formation pathway for polycyclic aromatic nitrogen heterocycles (PANHs) has been found. The reaction of phenylnitrene and the propargyl radical leads to quinoline, proving that nitrenes are suitable precursors for nitrogen incorporation mechanisms.
Rahel Arns   +6 more
wiley   +1 more source

Dust distribution in circumstellar shells [PDF]

open access: yesProceedings of the International Astronomical Union, 2011
AbstractWe present numerical simulations of the hydrodynamical interactions that produce circumstellar shells. These simulations include several scenarios, such as wind-wind interaction and wind-ISM collisions. In our calculations we have taken into account the presence of dust in the stellar wind. Our results show that, while small dust grains tend to
van Marle, Allard Jan   +3 more
openaire   +2 more sources

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