Results 31 to 40 of about 17,929 (222)

Early evolution of spherical ejecta expanding into the circumstellar matter at ultra-relativistic speeds

, 2012
We present a new self-similar solution describing early evolution of an ultra-relativistic flow resulting from a collision of homologously expanding spherical ejecta with the circumstellar matter, in which a shock wave propagates in the circumstellar ...
Nakamura, Ko, Shigeyama, Toshikazu, Suzuki, Akihiro   +2 more
core   +1 more source

Diagnostic of the Symbiotic Stars Environment by Thomson, Raman and Rayleigh Scattering Processes

Acta Polytechnica CTU Proceedings, 2015
Symbiotic stars are long-period interacting binaries consisting of a cool giant as the donor star and a white dwarf as the acretor. Due to acretion of the material from the giant’s stellar wind, the white dwarf becomes very hot and luminous.
M. Sekeráš, A. Skopal
doaj   +1 more source

The dust disk of HR4049 [PDF]

, 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, Beintema, Buss, C. Dominik, C. P. Dullemond, Chen, Chiang, Cuzzi, de Graauw, Dominik, Draine, Dullemond, Geballe, Guillois, H. van Winckel, J. Cami, Jeffreys, Johnson, Joshi, Kenyon, Kessler, Lamers, Mellema, Miyake, Monier, Pringle, Roddier, Sahai, Savage, Tielens, van Winckel, van Winckel, Waelkens, Waelkens, Waelkens, Waters, Waters, Zuckerman   +37 more
core   +3 more sources

Star Formation and the Circumstellar Matter of Young Stellar Objects [PDF]

Symposium - International Astronomical Union, 1987
We propose that the formation of low mass stars in molecular clouds takes place in four stages. The first stage is the formation of slowly rotating cloud cores through the slow leakage of magnetic (and turbulent) support by ambipolar diffusion. These cores asymptotically approach quasistatic states resembling singular isothermal spheres, but such end ...
Frank H. Shu, Fred C. Adams
openaire   +1 more source

Rings, Shells, and Arc Structures Around B[e] Supergiants. I. Classical Tools of Nonlinear Hydrodynamics

The Astrophysical Journal
Structures in circumstellar matter reflect both fast processes and quasi-equilibrium states. A geometrical diversity of emitting circumstellar matter is observed around evolved massive stars, in particular around B[e] supergiants.
Dieter H. Nickeler, Michaela Kraus
doaj   +1 more source

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

The 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, Takashi Nagao, Keiichi Maeda, Hanindyo Kuncarayakti, Masaomi Tanaka, Koji S. Kawabata, Tatsuya Nakaoka, Miho Kawabata, Masayuki Yamanaka, Kentaro Aoki, Keisuke Isogai, Mao Ogawa, Akito Tajitsu, Ryo Imazawa   +13 more
doaj   +1 more source

Circumstellar matter as detected by IRAS - Some systematics [PDF]

Symposium - International Astronomical Union, 1987
Most of the sources noted by the Infrared Astronomical Satellite are, as expected, more or less normal cool giant stars, but a very large number of objects of earlier spectral type were also picked up. These cases must involve, in a variety of ways, circumstellar gas and dust.
openaire   +1 more source

A low optical depth region in the inner disk of the HerbigAe star HR5999 [PDF]

, 2011
Circumstellar disks surrounding young stars are known to be the birthplaces of planets, and the innermost astronomical unit is of particular interest.
A. Isella, A. Mérand, A. Natta, Bagnoli, Benisty, Chelli, de Winter, Dullemond, E. Thiébaut, Eiroa, Eisner, Eisner, Eisner, F. Malbet, F. Massi, G. Weigelt, Grady, Haubois, Henning, Hillenbrand, Hubrig, Isella, Isella, J. L. Monin, J. P. Berger, Jennison, Kama, Kraus, Kraus, L. Testi, Lachaume, Le Bouquin, Le Bouquin, M. Benisty, M. Vannier, Millan-Gabet, Monnier, Monnier, Monnier, Natta, P. J. V. Garcia, Pauls, Perez, Perez, Petrov, Pollack, Preibisch, Renard, Rodrigues, S. Renard, Schöller, Siebenmorgen, Sitko, Stecklum, Strong, Tannirkulam, Tannirkulam, Tatulli, Thiébaut, Tjin, van Boekel, Weingartner, Zhao   +62 more
core   +3 more sources

Confined Chemistry in Space: Zeolite‐Supported Fe13 Nanoclusters Modulate CS Reactivity

Small Structures, Volume 7, Issue 3, March 2026.
The study explores how an Fe13 cluster confined in chabazite reshapes the reaction of CS and H2 under astrochemical conditions. Confinement promotes C–S bond cleavage over hydrogenation, directing chemistry toward CH4 and H2S formation. Additional CS enables CS2 and C2 species. Microkinetic analysis identifies protoplanetary environments where zeolites
Gerard Pareras, Albert Rimola
wiley   +1 more source

Discovery of Volatile Gas in the Giant Impact Disk Around the 150 Myr Old HD 23514

The Astrophysical Journal Letters
We report the discovery of CO _2 gas emission around HD 23514, an F5V star in the ∼150 Myr old Pleiades cluster, hosting one of the rare giant-impact disks with unique mineralogy dominated by silica dust. We show that the dust feature remains stable over
Kate Y. L. Su, Attila Moór, Chengyan Xie, Ilaria Pascucci, George H. Rieke, Ágnes Kóspál, Mark C. Wyatt, Péter Ábrahám, Luca Matrà, Zoe Roumeliotis, D. J. Wilner   +10 more
doaj   +1 more source