Results 41 to 50 of about 3,278,550 (239)

Are Giant Planets Forming Around HR 4796A? [PDF]

, 2003
We have obtained FUSE and HST STIS spectra of HR 4796A, a nearby 8 Myr old main sequence star that possesses a dusty circumstellar disk whose inclination has been constrained from high resolution near-infrared observations to be ~17 deg from edge-on.
Abgrall H., Augereau J. C., C. H. Chen, Holweger H., I. Kamp, Liseau R., Liseau R.   +6 more
core   +1 more source

AC Her: Evidence of the First Polar Circumbinary Planet

The Astrophysical Journal Letters, 2023
We examine the geometry of the post–asymptotic giant branch (AGB) star binary AC Her and its circumbinary disk. We show that the observations describe a binary orbit that is perpendicular to the disk with an angular momentum vector that is within 9° of ...
Rebecca G. Martin, Stephen H. Lubow, David Vallet, Narsireddy Anugu, Douglas R. Gies   +4 more
doaj   +1 more source

Analysis of Numerical Algorithms for Computing Rapid Momentum Transfers between the Gas and Dust in Simulations of Circumstellar Disks [PDF]

Astronomy reports (Print), 2018
Approaches used in modern numerical simulations of the dynamics of dust and gas in circumstellar disks are tested. The gas and dust are treated like interpenetrating continuous media that can exchange momentum.
O. Stoyanovskaya, O. Stoyanovskaya, E. Vorobyov, V. N. Snytnikov, V. N. Snytnikov   +4 more
semanticscholar   +1 more source

MODELS OF CIRCUMSTELLAR MASERS IN BIPOLAR OUTFLOWS

Odessa Astronomical Publications, 2017
Sources of molecular maser radio emission in envelopes of late-type variable stars (red giants and supergiants) are considered. Radio and optical data on asymmetry of mass loss process in red giants are briefly reviewed.
G. M. Rudnitskij
doaj   +1 more source

The Imprint of Massive Stellar Evolution on Circumstellar Gas [PDF]

Symposium - International Astronomical Union, 1995
We follow the interaction of massive stars with their circumstellar media over their entire lifetimes by combining several numerical models. We use a stellar evolution model for 35 and 60 M⊙ stars (Langer et al. in preparation) as inner boundary conditions for one- and two-dimensional gas dynamical models of the circumstellar medium using ZEUS (Stone ...
Guillermo García-Segura, Mordecai-Mark Mac Low, Norbert Langer   +2 more
openaire   +1 more source

On the gas temperature in circumstellar disks around A stars [PDF]

, 2001
In circumstellar disks or shells it is often assumed that gas and dust temperatures are equal where the latter is determined by radiative equilibrium. This paper deals with the question whether this assumption is applicable for tenous circumstellar disks
Aikawa, Aitken, Artymowicz, Artymowicz, Augereau, Bakes, Bell, Black, Burke, Chiang, Chini, Clavel, D'Alessio, Dent, Draine, Dutrey, Feuerbacher, G.-J. van Zadelhoff, Gilman, Habing, Hollenbach, Hollenbach, Holweger, Holweger, I. Kamp, Jaquet, Jolly, Kamp, Kurucz, Launay, Le Bourlot, Liseau, Mc Kee, Pantin, Roberge, Sandford, Schinke, Stephens, Sternberg, Telesco, Thi, Tielens, Tielens, van der Bliek, Watson, Welsh, Yamashita   +46 more
core   +4 more sources

Detection of circumstellar gas associated with GG Tauri

The Astrophysical Journal, 1993
Double-peaked (C-12)O (1-0) emission centered on the young T Tauri star GG Tau possesses a line profile which may be modeled on the assumption that CO emission arises in an extended circumstellar disk. While bounds on the observed gas mass can be estimated on this basis, it is suggested that a large amount of mass could lie within a small and optically
SKRUTSKIE, MF, Snell, RL, STROM, KM, STROM, SE, EDWARDS, S, FUKUI, Y, MIZUNO, A, HAYASHI, M, OHASHI, N   +8 more
openaire   +2 more sources

Broad emission lines from opaque electron-scattering environment of SN 1998S [PDF]

, 2001
I propose that broad narrow-topped emission lines with full width at zero intensity >20000 km/s, seen in early-time spectra of SN 1998S, originate from a dense circumstellar gas and not from the supernova ejecta.
Arnett, Arnett, Auer, Blinnikov, Chevalier, Chevalier, Chevalier, Chugai, Chugai, Falk, Fassia, Fassia, Filippenko, Filippenko, Fransson, Gerardy, Grasberg, Hillier, Lentz, Leonard, Liu, Mihalas, N.N. Chugai, Nadyozhin, Niemela, Sobolev, Sollerman, Stathakis, Weymann, Woosley   +29 more
core   +3 more sources

DETERMINATION OF THE SPECTRAL TYPE AND LUMINOSITY OF THE HOT COMPONENT OF THE ECLIPSING BINARY STAR RZ ERI

Odessa Astronomical Publications, 2017
By using the spectra taken at 6m telescope and the methods of two-dimensional spectral classification, the non-ordinarity of the main star in RZ Eri is shown.
V. G. Karetnikov, E. V. Menchenkova, O. I. Syrov   +2 more
doaj   +1 more source

Variable Sodium Absorption in a Low-Extinction Type Ia Supernova [PDF]

, 2009
Recent observations have revealed that some Type Ia supernovae exhibit narrow, time-variable Na I D absorption features. The origin of the absorbing material is controversial, but it may suggest the presence of circumstellar gas in the progenitor system ...
Afanasyev, Aldering, Alexei V. Filippenko, Asplund, Avishay Gal-Yam, Badenes, Badnell, Benetti, Benetti, Blondin, Blondin, Borkowski, Brown, Chandrasekhar, Crotts, Daniel N. Sauer, Erik Rosolowsky, Ferdinando Patat, Filippenko, Filippenko, Gonzalez-Hernández, Gregory J. Herczeg, Herbig, Hicken, Howell, Howell, Hughes, Ihara, Immler, J. Craig Wheeler, Jeffrey M. Silverman, Jha, Joshua D. Simon, Kathryn M. G. Peek, Kennicutt, Kerzendorf, Koribalski, Leonard, Li, Li, Marietta, Matheson, Matheson, Mazzali, Mazzali, Miller, Mohan Ganeshalingam, Monard, Moore, Murray, Orly Gnat, Panagia, Paolo A. Mazzali, Peter Nugent, Poole, Prieto, Quimby, R. Paul Butler, Riess, Robert M. Quimby, Robert P. Kirshner, Ruiz-Lapuente, Ryan J. Foley, Scannapieco, Schlegel, Simon, Spitzer, Stephane Blondin, Steven S. Vogt, Sullivan, Tanaka, Totani, Wang, Wang, Wang, Wang, Weidong Li, Welty, Williams, Wood-Vasey   +79 more
core   +3 more sources