Results 51 to 60 of about 2,045,808 (218)

Origin of Circumstellar Matter in the Spectroscopic Binary CX Dra [PDF]

open access: yesInternational Astronomical Union Colloquium, 2000
AbstractWe examine the periodic component in the polarization of CX Dra, a spectroscopic binary with an orbital period of 7 days. We find that this component originates in dense matter located in the direction preceding the secondary by about 4.5° from the primary-secondary direction. This dense scattering region is attributable to the region where the
Hidetoshi Iwamatsu   +2 more
openaire   +1 more source

The circumstellar matter distribution of massive young stellar objects [PDF]

open access: yes, 2016
A multiwavelength study of the circumstellar matter distribution of massive young stellar objects (MYSOs) was conducted. First, the potential of the new Herschel 70 micron data to resolve MYSOs in the Hi-GAL survey was analysed.
Olguin Choupay, Fernando Andres
core   +3 more sources

SN 2020uem: a Possible Thermonuclear Explosion within a Dense Circumstellar Medium (II). The Properties of the CSM from Polarimetry and Light-curve Modeling

open access: yesThe Astrophysical Journal, 2023
Type IIn/Ia-CSM supernovae (SNe IIn/Ia-CSM) are classified by their characteristic spectra, which exhibit narrow hydrogen emission lines originating from strong interaction with a circumstellar medium (CSM) together with broad lines of intermediate-mass ...
Kohki Uno   +13 more
doaj   +1 more source

Toward an efficient second‐order method for computing the surface gravitational potential on spherical‐polar meshes

open access: yesAstronomische Nachrichten, Volume 345, Issue 8, October 2024.
Abstract Astrophysical accretion discs that carry a significant mass compared with their central object are subject to the effect of self‐gravity. In the context of circumstellar discs, this can, for instance, cause fragmentation of the disc gas, and—under suitable conditions—lead to the direct formation of gas‐giant planets.
Oliver Gressel, Udo Ziegler
wiley   +1 more source

The Near-infrared Echo from SN 2023xgo: Evidence for a Massive Presupernova Eruption in a Type Ibn/Icn Supernova

open access: yesThe Astrophysical Journal Letters
We present near-infrared (NIR) and optical observations and analysis of the Type Ibn/Icn supernova (SN) 2023xgo, spanning the period from 2 to 100 days past explosion.
Masayuki Yamanaka, Takahiro Nagayama
doaj   +1 more source

First direct detection of large polycyclic aromatic hydrocarbons on asteroid (162173) Ryugu samples: An interstellar heritage

open access: yesNatural Sciences, Volume 4, Issue 4, October 2024.
Large free aromatic species, with up to 61 carbon atoms, were detected in grains of the Ryugu carbonaceous asteroid using ultra‐sensitive two‐step laser mass spectrometry. This discovery confirms the presence of large polycyclic aromatic hydrocarbons in the interstellar medium and provides new information on the formation and evolution of organic ...
Hassan Sabbah   +3 more
wiley   +1 more source

Laboratory studies of circumstellar and interstellar materials

open access: yes, 2009
When the most primitive types of meteorite (chondrites) and interplanetary dust particles (IDPs) formed in the solar protoplanetary disk (solar nebula), all of them incorporated at least two types of presolar material: interstellar organic matter and ...
C.M.O.D. Alexander
core   +1 more source

Correlated Molybdenum, Ruthenium, and Barium Isotope Anomalies in Presolar Silicon Carbide Grains

open access: yesThe Astrophysical Journal
We 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
doaj   +1 more source

SEARCHING FOR LIGHT ECHOES DUE TO CIRCUMSTELLAR MATTER IN SNe Ia SPECTRA [PDF]

open access: yesThe Astrophysical Journal, 2015
We present an analytical model for light echoes (LEs) coming from circumstellar material (CSM) around Type Ia Supernovae (SNe Ia). Using this model we find two spectral signatures at 4100 ? and 6200 ? that are useful to identify LEs during the Lira law phase (between 35 and 80 days after maximum light) coming from nearby CSM at distances of 0.01?0.25 ...
Sebastián Marino   +5 more
openaire   +8 more sources

Electron microscopy observations of the diversity of Ryugu organic matter and its relationship to minerals at the micro‐ to nano‐scale

open access: yesMeteoritics &Planetary Science, Volume 59, Issue 8, Page 2023-2043, August 2024.
Abstract Transmission electron microscopy analyses of Hayabusa2 samples show that Ryugu organic matter exhibits a range of morphologies, elemental compositions, and carbon functional chemistries consistent with those of carbonaceous chondrites that have experienced low‐temperature aqueous alteration.
Rhonda M. Stroud   +112 more
wiley   +1 more source

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