Results 41 to 50 of about 584 (186)

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

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

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

Gas-phase Molecules in Protoplanetary Nebulae with the 21 μm Emission Feature

open access: yesThe Astronomical Journal
It has been more than 30 years since the enigmatic 21 μ m emission feature was first discovered in protoplanetary nebulae (PPNs). Although dozens of different dust carrier candidates have been proposed, there is as yet no widely accepted one.
Jian-Jie Qiu   +8 more
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

Effect of Matter Accretion on Lithium Enhancement of Giants

open access: yesThe Astrophysical Journal
A subset of low-mass giants (
Xue-Feng Li   +5 more
doaj   +1 more source

Circumstellar matter, with particular reference to jets and molecular flows [PDF]

open access: yesSymposium - International Astronomical Union, 1987
Circumstellar matter exists in many forms, such as winds from early and from late type stars, in infra-red sources and OH and H2O masers, in X-ray sources and jets, and molecular flows and Herbig-Haro objects. There is considerable diversity in the nature of the starlike bodies that underlie these phenomena.
openaire   +2 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

Properties of the Variation of the Infrared Emission of OH/IR Stars III. The M Band Light Curves [PDF]

open access: yesJournal of Astronomy and Space Sciences, 2010
To study properties of the pulsation in the infrared emission for long period variables, we have collected and analyzed the infrared observational data at M band for 12 OH/IR stars.
Young-Joo Kwon, Kyung-Won Suh
doaj   +1 more source

SN 2022jox: An Extraordinarily Ordinary Type II SN with Flash Spectroscopy

open access: yesThe Astrophysical Journal
We present high-cadence optical and ultraviolet (UV) observations of the Type II supernova (SN), SN 2022jox which exhibits early spectroscopic high-ionization flash features of H i , He ii , C iv , and N iv that disappear within the first few days after ...
Jennifer E. Andrews   +22 more
doaj   +1 more source

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