Results 11 to 20 of about 717 (184)
Is Phenylnitrene a Missing Link in the Formation of Polycyclic Aromatic Nitrogen Heterocycles? [PDF]
Angew Chem Int Ed EnglA 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.
Arns R +6 more
europepmc +2 more sources
The Circumstellar Dust of “Born-Again” Stars [PDF]
EAS Publications Series, 2015 We describe the evolution of the carbon dust shells around Very Late Thermal Pulse (VLTP) objects as seen at infrared wavelengths. This includes a 20-year overview of the evolution of the dust around Sakurai's object (to which Olivier made a seminal contribution) and FG Sge. VLTPs may occur during the endpoint of as many as 25% of solar mass stars, and
Evans, A. +3 more
openaire +2 more sources
The Astrophysical Journal, 2023 The first step toward planet formation is grain growth from (sub)micrometer to millimeter/centimeter sizes. Grain growth has been reported not only in Class II protoplanetary disks but also in Class 0/I protostellar envelopes.
Ilseung Han +4 more
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The temperature of nonspherical circumstellar dust grains [PDF]
Astronomy Letters, 2000 18 pages, 9 figures, to appear in Astronomy Letters, Vol.
Voshchinnikov, N. V., Semenov, D. A.
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Temperature Distributions in Circumstellar Dust Shells [PDF]
Symposium - International Astronomical Union, 1987 The knowledge of the temperature distribution in circumstellar dust shells (CDS) is needed for both the calculation of the emergent IR spectrum and the modelling of physical processes, e.g. dust formation.
Th. Henning, J. Gürtler
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The Astrophysical Journal Supplement Series, 2023 Astronomical observations of the polarized intensity of scattered visible light have revealed the presence of dust envelopes around different types of evolved stars.
Juan Carlos Gómez Martín +10 more
doaj +1 more source
International Journal of Chemical Kinetics, Volume 55, Issue 11, Page 731-742, November 2023., 2023 Abstract The kinetics of the tautomerization of thio‐imidic acids RC(SH)NH were determined at low (50–300 K) and high (500–1500 K) temperatures as R was varied to encompass mono‐ and diatomic species H, F, HO, NC, CN through H2N, HC(O), HC(S), HC≡ C, H3C, F3C, HOCH2, H2C=CH, CH3C(O), H2NCH2 and including ethyl, isopropyl and phenyl groups. The presence
Judith Würmel, John M. Simmie
wiley +1 more source
Evaluating the GeoSnap 13‐μ$$ \mu $$m cutoff HgCdTe detector for mid‐IR ground‐based astronomy
Astronomische Nachrichten, Volume 344, Issue 8-9, October-November 2023., 2023 Abstract New mid‐infrared HgCdTe (MCT) detector arrays developed in collaboration with Teledyne Imaging Sensors (TIS) have paved the way for improved 10‐μ$$ \mu $$m sensors for space‐ and ground‐based observatories. Building on the successful development of longwave HAWAII‐2RGs for space missions such as NEO Surveyor, we characterize the first 13‐μ ...
Jarron M. Leisenring +15 more
wiley +1 more source
From Dust to Nanodust: Resolving Circumstellar Dust from the Colliding-wind Binary Wolf-Rayet 140
The Astrophysical Journal, 2023 Wolf-Rayet (WR) 140 is the archetypal periodic dust-forming colliding-wind binary that hosts a carbon-rich WR (WC) star and an O-star companion with an orbital period of 7.93 yr and an orbital eccentricity of 0.9.
Ryan M. Lau +19 more
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International Journal of Chemical Kinetics, Volume 55, Issue 7, Page 381-391, July 2023., 2023 Abstract A number of amides, RC(O)NH2, have been detected spectroscopically in the space between the stars. Naturally the study of how these are formed is an important question on the path of chemical evolution from the elements C, H, N, O, P, … to life because the so‐called peptide‐bond −C(O)−NH− is a key linkage in poly‐amino acids or proteins.
Judith Würmel, John M. Simmie
wiley +1 more source