Results 61 to 70 of about 3,278,550 (239)

The Radial Distribution and Excitation of H2 around Young Stars in the HST-ULLYSES Survey

The Astronomical Journal, 2023
The spatial distribution and evolution of gas in the inner 10 au of protoplanetary disks form the basis for estimating the initial conditions of planet formation.
Kevin France, Nicole Arulanantham, Erin Maloney, P. Wilson Cauley, P. Ábrahám, Juan M. Alcalá, Justyn Campbell-White, Eleonora Fiorellino, Gregory J. Herczeg, Brunella Nisini, Miguel Vioque   +10 more
doaj   +1 more source

SN 2011hw: Helium-Rich Circumstellar Gas and the Luminous Blue Variable to Wolf-Rayet Transition in Supernova Progenitors [PDF]

, 2012
We present optical photometry and spectroscopy of the peculiar Type IIn/Ibn supernova (SN) 2011hw. Its light curve exhibits a slower decline rate than normal SNe Ibc, with a peak absolute magnitude of 19.5 (unfiltered) and a secondary peak 20–30 days ...
N. Smith, J. Mauerhan, J. Silverman, M. Ganeshalingam, A. Filippenko, S. Cenko, K. Clubb, M. Kandrashoff   +7 more
semanticscholar   +1 more source

Fe I in the β Pictoris circumstellar gas disk [PDF]

Astronomy & Astrophysics, 2017
The young planetary system β Pictoris is surrounded by a circumstellar disk of dust and gas. Because both dust and gas have a lifetime shorter than the system age, they need to be replenished continuously. The gas composition is partly known, but its location and its origin are still a puzzle. The gas source could be the exocomets (or so-called falling
Vidal-Madjar, A., Kiefer, F., Lecavelier Des Etangs, A., Bourrier, V., Ehrenreich, D., Ferlet, R., Hébrard, G., Wilson, P. A.   +7 more
openaire   +3 more sources

THE SPECTROSCOPY OF THE PULSATING CARBON STAR R Lep

Odessa Astronomical Publications, 2017
The first results of detailed spectroscopy are presented for carbon Mira R Leporis. This long-period variable is undergoing deep fadings, apparently caused by dust formation around the star.
L. Zacs, O. Alksnis
doaj   +1 more source

Gas phase formation of c-SiC3 molecules in the circumstellar envelope of carbon stars

Proceedings of the National Academy of Sciences of the United States of America, 2019
Significance Since the detection of methylidyne (CH) in deep space over 80 y ago, about 200 molecules and molecular ions from molecular hydrogen to fullerenes have been observed in interstellar and circumstellar environments, but the synthesis of ...
Tao Yang, Luke W. Bertels, Beni B. Dangi, Xiaohu. Li, M. Head‐Gordon, R. Kaiser   +5 more
semanticscholar   +1 more source

Molecular Hydrogen emission from disks in the eta Chamaeleontis cluster

, 2007
Disks in the 6 Myr old cluster eta Chamaeleontis were searched for emission from hot H2. Around the M3 star ECHAJ0843.3-7905 we detect circumstellar gas orbiting at ~2 AU. If the gas is UV-excited, the ro-vibrational line traces a hot gas layer supported
Greaves, Jane S., Howat, Suzanne K. Ramsay   +1 more
core   +1 more source

Radio Observations of Six Young Type Ia Supernovae

The Astrophysical Journal, 2023
Type Ia supernovae (SNe Ia) are important cosmological tools, probes of binary star evolution, and contributors to cosmic metal enrichment; yet, a definitive understanding of the binary star systems that produce them remains elusive.
C. E. Harris, Sumit K. Sarbadhicary, L. Chomiuk, Anthony L. Piro, D. J. Sand, S. Valenti   +5 more
doaj   +1 more source

Spatially Resolved STIS Spectroscopy of SN 1987A: Evidence for Shock Interaction with Circumstellar Gas [PDF]

, 1997
Visual and ultraviolet spatially resolved (~0.″1) spectra of SN 1987A obtained on days 3715 and 3743 with the Space Telescope Imaging Spectrograph on the Hubble Space Telescope show that the high-velocity supernova debris is colliding with circumstellar ...
G. Sonneborn, C. Pun, R. Kimble, T. Gull, P. Lundqvist, R. McCray, P. Plait, A. Boggess, C. Bowers, A. Danks, J. Grady, S. Heap, S. Kraemer, D. Lindler, J. Loiacono, S. Maran, H. Moos, B. Woodgate   +17 more
semanticscholar   +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

Dynamics of the circumstellar gas in the Herbig Ae stars BF Orionis, SV Cephei, WW Vulpeculae and XY Persei [PDF]

, 2004
We present high resolution (λ/∆λ = 49 000) ´ spectra of the intermediate mass, pre-main sequence stars BF Ori, SV Cep, WW Wul and XY Per. The spectra cover the range 3800−5900 A and monitor the stars on time scales of months and days.
A. Mora, C. Eiroa, A. Natta, C. Grady, D. D. Winter, J. Davies, R. Ferlet, A. Harris, L. F. Miranda, B. Montesinos, R. Oudmaijer, J. Palacios, A. Quirrenbach, H. Rauer, A. Alberdi, A. Cameron, H. Deeg, F. Garzón, K. Horne, B. Merín, A. Penny, J. Schneider, E. Solano, Y. Tsapras, P. Wesselius   +24 more
semanticscholar   +1 more source