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Article
The accretion of interstellar matter by white dwarfs
The problem of the energy released by interstellar matter in its accretion by low-luminosity stars is examined. It is found that nearly all the gravitational energy is available as the energy source for the ac...
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Chapter and Conference Paper
Infrared Emission from HII Regions
In talking about infrared emission from HII regions, I am supposed to review the observational results and discuss possible theoretical interpretation. Recent reviews on the observational aspects are available...
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Chapter and Conference Paper
Theoretical Aspects of the Infrared Emission from HII Regions
Treatment of the subject of IR emission from HII regions will necessitate considerable discussion of the parameters and properties of dust grains. Therefore I feel that I should first justify why and how dust ...
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Chapter and Conference Paper
Systematic Variation of the Helium Ionization in Galactic HII Regions
The existence of a gradient of the ionized helium abundance as a function of the galactic radius was first noted by Churchwell et al. (1974). This result has recently been confirmed by the much more complete s...
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Chapter and Conference Paper
The Properties of Dust in Planetary Nebulae
We present and discuss the properties of dust grains mixed with the ionized gas in planetary nebulae.
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Chapter
Wind Characteristics of the 07 n Star HD 217086 in the Cep OB 3 Association
The 07 n star HD 217086 which provides the ionization of the H II region S 155 A and is the brightest member of the Cep OB 3 association, has been observed in the ultraviolet with IUE. From an analysis of the ...
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Chapter and Conference Paper
Multifrequency observations of recent supernovae
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Chapter
Observations of Supernovae
The observations of supernovae are reviewed and their main implications are shortly discussed.
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Chapter
Supernovae and Their Remnants
Supernovae (SNe) and supernova remnants (SNRs) represent an important area of research in astrophysics because they are central to our understanding of such diverse fields as the late stages of stellar evoluti...
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Chapter and Conference Paper
Type Ib supernovae: What they may be and what they are not
We show that the progenitors of Type Ib supernovae are likely to be moderately massive stars (M ∼ 7 M⊙) in binary systems and we argue that the hypothesis that they originate from very massive stars (M > 20 M⊙) i...
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Chapter and Conference Paper
Ultraviolet observations of SN 1987A
The results of IUE observations of- SN 1987A are presented and discussed. One of the most important conclusions is that the direct progenitor of the supernova was a blue supergiant (Sk -69 202) that, however, ...
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Chapter
Radio and Infrared Properties of Young Stars
The observations and the theory of the radio and infrared emission from pre-main-sequence stars are reviewed and discussed.
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Chapter and Conference Paper
IUE Observations of Supernovae
The launch of the International Ultraviolet Explorer (IUE) satellite in early 1978 marked the beginning of a new era for SN studies because of its capability of measuring the ultraviolet emission of objects as...
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Chapter and Conference Paper
A Supernova with a Difference, SN 1986J
A new radio source was discovered on 21 August 1986 by VAN GORKOM et al. [1] during their study of the nearby, edge-on, spiral galaxy NGC891. Because the source lay in the disk and had HI absorption features c...
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Chapter and Conference Paper
On the Nature of Type Ib Supernova Progenitors
The realization that there is a separate subclass of Type I supernovae (SNe) to be denoted as Type Ib came after the detailed study of the SN 1983N in M83 (PANAGIA et al [1]; see also PANAGIA [2], WHEELER and LEV...
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Chapter and Conference Paper
A Third, Inner Light Echo Ring Around SN 1987A
At the beginning of this year evidence has been found for a third, inner echo near SN 1987A (BOND et al. [l]). This discovery is of great importance because the detection of an echo so close to the SN 1987A revea...
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Chapter
Ionized Winds from Young Stellar Objects
The observations and the theory of the radio and infrared emission from ionized winds of young stellar objects are reviewed and discussed.
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Article
Origins revealed in demise
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Chapter
Distance Scale from Supernovae
Supernovae have been playing an ever increasing role in the determination of the key cosmological parameters. They are extremely luminous point sources whose brightness at maximum rivals that of their host gal...
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Article
Gravitational microlensing by low-mass objects in the globular cluster M22
Gravitational microlensing offers a means of determining directly the masses of objects ranging from planets to stars, provided that the distances and motions of the lenses and sources can be determined1,2. A glo...
