Results 41 to 50 of about 293,009 (201)
Formation and destruction of dust grains in circumstellar regions [PDF]
Symposium - International Astronomical Union, 1987 The existence of circumstellar dust in late-type stars is connected with stellar pulsations since periodic shocks accompanying pulsations seem to be the most probable mechanism of the gas density increase needed for condensation of dust particles in outer layers of the stellar atmosphere.
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Large grains can grow in circumstellar discs [PDF]
Proceedings of the International Astronomical Union, 2013 AbstractWe perform coagulation & fragmentation simulations to understand grain growth in T Tauri & brown dwarf discs. We present a physically-motivated approach using a probability distribution function for the collision velocities and separating the deterministic & stochastic velocities.
Meru, Farzana +3 more
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The Astrophysical Journal, 2023 ASASSN-21qj is a distant Sun-like star that recently began an episode of deep dimming events after no prior recorded variability. Here we examine archival and newly obtained optical and near-infrared data of this star.
Jonathan P. Marshall +8 more
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CONSTRAINTS ON THE RADIAL VARIATION OF GRAIN GROWTH IN THE AS 209 CIRCUMSTELLAR DISK [PDF]
The Astrophysical Journal, 2012 7 pages, 5 figures, Accepted to ...
Pérez LM +20 more
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Large dust grains in the inner region of circumstellar disks [PDF]
Astronomy & Astrophysics, 2006 CONTEXT: Simple geometrical ring models account well for near-infrared interferometric observations of dusty disks surrounding pre-main sequence stars of intermediate mass. Such models demonstrate that the dust distribution in these disks has an inner hole and puffed-up inner edge consistent with theoretical expectations.
Isella A, Testi L, Natta A
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m spectra of globular cluster red giants: circumstellar silicate dust grains in 47 Tucanae (NGC 104)
, 2006 We present 8–13 μm spectra of eight red giants in the globular cluster 47 Tucanae (NGC 104), obtained at the European Southern Observatory 3.6 m telescope. These are the first mid-infrared spectra of metal-poor, low-mass stars.
R. D. Gehrz +7 more
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MgS grain component in circumstellar shells
The Astrophysical Journal, 1985 In this letter, far-infrared spectrophotometry (30-55 microns) and photometry (53-200 microns) are presented which define, for the first time, the long wavelength limit of the previously unidentified 30 micron emission feature found in certain extreme carbon star spectra. The spectral similarities are sufficiently similar to those of solid MgS that MgS
J. H. Goebel, S. H. Moseley
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The Presolar Grain Database. I. Silicon Carbide
The Astrophysical Journal Supplement SeriesThe Presolar Grain Database (PGD) contains the vast majority of isotope data (published and unpublished) on presolar grains and was first released as a collection of spreadsheets in 2009.
Thomas Stephan +10 more
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NanoSIMS-Analyse und hochauflösende Elektronenmikroskopie an präsolaren Silikaten aus roten Riesensternen und Supernovaexplosionen [PDF]
, 2009 This thesis deals with the analysis of “presolar” silicates and oxides by high resolution mass spectrometry and electron microscopy techniques. This “stardust” was identified by its extreme oxygen isotopic anomalies, which point to nucleosynthetic ...
Vollmer, Christian
core
Correlated Molybdenum, Ruthenium, and Barium Isotope Anomalies in Presolar Silicon Carbide Grains
The Astrophysical JournalWe have analyzed molybdenum, ruthenium, and barium isotopes simultaneously in 55 individual presolar silicon carbide (SiC) grains from the Murchison CM2 meteorite using the Chicago Instrument for Laser Ionization (or CHILI).
Thomas Stephan +5 more
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