Results 11 to 20 of about 13,144 (210)
, 2002 We present the Spectral Energy Distribution of HR 4049 based on literature data and new continuum measurements at 850 micron. The SED shows variable absorption in the UV, and a large IR excess, both caused by circumstellar dust.
Bakker +37 more
core +26 more sources
AGB Stars and Their Circumstellar Envelopes. I. the VULCAN Code
Universe, 2021 The interplay between AGB interiors and their outermost layers, where molecules and dust form, is a problem of high complexity. As a consequence, physical processes like mass loss, which depend on the chemistry of the circumstellar envelope, are often ...
Sergio Cristallo +4 more
doaj +1 more source
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
doaj +1 more source
Composite circumstellar dust grains [PDF]
Monthly Notices of the Royal Astronomical Society, 2016 We calculate the absorption efficiencies of composite silicate grains with inclusions of graphite and silicon carbide in the spectral range 5--25$\rm μm$. We study the variation in absorption profiles with volume fractions of inclusions. In particular we study the variation in the wavelength of peak absorption at 10 and 18$\rm μm$.
Gupta, Ranjan +2 more
openaire +2 more sources
On the Coupling of Grains to the Gas in Circumstellar Envelopes
Astrophysical Journal, 1972 exaly +2 more sources
The circumstellar disc in the Bok globule CB 26: Multi-wavelength observations and modelling of the dust disc and envelope [PDF]
, 2009 Circumstellar discs are expected to be the nursery of planets. Grain growth within such discs is the first step in the planet formation process. The Bok globule CB 26 harbours such a young disc.
Alonso-Albi +64 more
core +11 more sources
Angewandte Chemie, Volume 135, Issue 12, March 13, 2023., 2023 Out of the cold: Ammonia (NH3) and acetaldehyde (CH3CHO) are exposed to galactic cosmic ray proxies while frozen at 5 K to simulate the environment of an interstellar molecular cloud. Reactants undergo dissociation and radical recombination to produce glycinal (NH2CH2CHO) and acetamide (CH3CONH2) prior to tautomerization to 2‐aminoethenol (HOCHCHNH2 ...
Joshua H. Marks +5 more
wiley +2 more sources
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.
openaire +2 more sources
Universe, 2022 Presolar grains are microscopic dust grains that formed in the stellar winds or explosions of ancient stars that died before the formation of the solar system.
Nan Liu, Sergio Cristallo, Diego Vescovi
doaj +1 more source
Condensation Chemistry of Circumstellar Grains [PDF]
Symposium - International Astronomical Union, 1999 Thermochemical equilibrium calculations are successful in predicting the mineralogy as well as the major and trace element chemistry of circumstellar grains found in meteorites. The calculations also explain observations of dust close to AGB stars (within 1–3 stellar radii).
Katharina Lodders, Bruce Fegley
openaire +1 more source