Results 21 to 30 of about 740 (174)
Evolution of Gas and Dust in Circumstellar Disks [PDF]
Symposium - International Astronomical Union, 2000 A clear understanding of the chemical processing of matter as it is transferred from a molecular cloud to a planetary system depends heavily on the physical conditions endured by gas and dust as these accrete onto a disk and are incorporated into planetary bodies.
openaire +2 more sources
SPECTROSCOPIC MONITORING OF THE B[E] OBJECTS FSCMA AND MOCAM
Odessa Astronomical Publications, 2019 Objects with the B[e] phenomenon exhibit permitted and forbidden emission lines due to the presence of circumstellar ionized gas and large infrared excesses due to processing of the stellar radiation by circumstellar dust.
A. K. Kuratova +10 more
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Millimetre Observations of Maser-Emitting Planetary Nebulae
Galaxies, 2022 Observations in the millimetre bands of maser-emitting planetary nebulae (PNe) are crucial to study their circumstellar molecular gas at the beginning of the PN phase.
Lucero Uscanga +9 more
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Dynamics of cold circumstellar gas in debris discs
Monthly Notices of the Royal Astronomical SocietyABSTRACT Mounting observational evidence indicates that cold circumstellar gas is present in debris disc systems. This work focuses on various dynamical processes that debris disc gas may undergo. We review five mechanisms that can transport angular momentum and their applications to debris discs.
Can Cui +3 more
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Modeling Circumstellar Gas Emission around a White Dwarf Using cloudy
The Astronomical JournalThe chemical composition of an extrasolar planet is fundamental to its formation, evolution, and habitability. In this study, we explore a new way to measure the chemical composition of the building blocks of extrasolar planets by measuring the gas ...
Siyi Xu +11 more
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THE SPECTROSCOPY OF THE PULSATING CARBON STAR R Lep
Odessa Astronomical Publications, 2017 The first results of detailed spectroscopy are presented for carbon Mira R Leporis. This long-period variable is undergoing deep fadings, apparently caused by dust formation around the star.
L. Zacs, O. Alksnis
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Astronomische Nachrichten, Volume 347, Issue 3, March 2026.ABSTRACT Planetary nebulae represent a late evolutionary phase of low‐ to intermediate‐mass stars. In this article, we present the serendipitous discovery of a previously unknown, faint potential Galactic planetary nebula (PN) in the constellation Camelopardalis, identified during a survey‐inspection, aiming at the detection of dwarf companions of the ...
W. E. Celnik +12 more
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Confined Chemistry in Space: Zeolite‐Supported Fe13 Nanoclusters Modulate CS Reactivity
Small 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
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Discovery of Volatile Gas in the Giant Impact Disk Around the 150 Myr Old HD 23514
The Astrophysical Journal LettersWe report the discovery of CO _2 gas emission around HD 23514, an F5V star in the ∼150 Myr old Pleiades cluster, hosting one of the rare giant-impact disks with unique mineralogy dominated by silica dust. We show that the dust feature remains stable over
Kate Y. L. Su +10 more
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