Results 61 to 70 of about 301,064 (245)
Millimetre Observations of Maser-Emitting Planetary Nebulae
Galaxies, 2022 Observations in the millimetre bands of maser-emitting planetary nebulae (PNe) are crucial to study their circumstellar molecular gas at the beginning of the PN phase.
Lucero Uscanga +9 more
doaj +1 more source
Polarimetric variations of binary stars. II. Numerical simulations for circular and eccentric binaries in Mie scattering envelopes [PDF]
, 2001 We present numerical simulations of the periodic polarimetric variations produced by a binary star placed at the center of an empty spherical cavity inside a circumbinary ellipsoidal and optically thin envelope made of dust grains.
Bastien P. +9 more
core +3 more sources
Circumstellar envelope of the supergiant 89 Herculis [PDF]
Symposium - International Astronomical Union, 1987 A bright enigmatic supergiant, 89 Her (HD 163506; F2Ia, Mbol=-7m.5), exhibits the light variations (Percy et al. 1979, Fernie 1981, 1983) as well as the changes of radial velocities and structures of Balmer and sodium lines. Sargent and Osmer (1969) have given some evidences for the existence of expanding circumstellar envelope around 89 Her and have ...
J. L. Climenhaga +4 more
openaire +1 more source
Recent Progress in Finding Binary Systems with the B[e] Phenomenon
Galaxies, 2023 This paper describes recent studies of the FS CMa-type objects, a group of stars showing the B[e] phenomenon defined in 2007. The objects exhibit strong emission-line spectra with both permitted and forbidden lines suggesting the presence of a B-type ...
Anatoly S. Miroshnichenko +11 more
doaj +1 more source
Detection of Pre-Shock Dense Circumstellar Material of SN 1978K [PDF]
, 1998 The supernova SN 1978K has been noted for its lack of emission lines broader than a few thousand km/s since its discovery in 1990. Modeling of the radio spectrum of the peculiar SN 1978K indicates the existence of HII absorption along the line of sight ...
Adeline Caulet +11 more
core +3 more sources
Circumstellar Envelopes of OH-IR Sources [PDF]
Symposium - International Astronomical Union, 1987 This article reviews recent radio observations of maser emission from OH, H2O and SiO molecules in the circumstellar envelopes of OH-IR sources. The different radio lines require different conditions for their excitation, and each therefore probes different regions in the circumstellar envelope. For some stars radio interferometer maps of several maser
openaire +1 more source
PHOTODETACHMENT AS A DESTRUCTION MECHANISM FOR CN− AND C3N− ANIONS IN CIRCUMSTELLAR ENVELOPES [PDF]
, 2013 Absolute photodetachment cross sections of two anions of astrophysical importance CN− and C3N− were measured to be (1.18 ± (0.03)stat(0.17)sys) × 10−17 cm2 and (1.43 ± (0.14)stat(0.37)sys) × 10−17 cm2, respectively, at the ultraviolet (UV) wavelength of ...
Sunil Kumar +7 more
semanticscholar +1 more source
AGB circumstellar envelopes: molecular observations [PDF]
Symposium - International Astronomical Union, 1999 Due to the low excitation requirements and easy observation from the ground, molecular line observations probably constitute our main source of empirical knowledge on circumstellar envelopes (CSEs) around AGB stars. The CO rotational transitions, the most intense ‘thermal’ lines, are efficiently used to determine the total gas content and its spatial ...
openaire +1 more source
WIDE BINARY EFFECTS ON ASYMMETRIES IN ASYMPTOTIC GIANT BRANCH CIRCUMSTELLAR ENVELOPES [PDF]
, 2012 Observations of increasingly higher spatial resolution reveal the existence of asymmetries in the circumstellar envelopes of a small fraction of asymptotic giant branch (AGB) stars.
Hyosun Kim, R. Taam
semanticscholar +1 more source
THE IONIZED CIRCUMSTELLAR ENVELOPES OF ORION SOURCE I AND THE BECKLIN-NEUGEBAUER OBJECT [PDF]
, 2012 The 229 GHz (λ1.3 mm) radio emission from Orion-KL was mapped with up to 0.″14 angular resolution with CARMA, allowing measurements of the flux densities of Source I (“SrcI”) and the Becklin-Neugebauer Object (BN), the two most massive stars in this ...
R. Plambeck +15 more
semanticscholar +1 more source