Results 31 to 40 of about 191,657 (282)

The Evidence for a Binary origin of the Young Planetary Nebula HB 12 [PDF]

open access: yes, 2006
The young planetary nebulae play an important role in stellar evolution when intermediate- to low-mass stars (0.8 $\sim$ 8 M$_\odot$) evolve from the proto-planetary nebulae phase to the planetary nebulae phase.
Hsia, Chih Hao   +2 more
core   +5 more sources

X-ray Observations of Planetary Nebulae since WORKPLANS I and Beyond

open access: yesGalaxies, 2020
Planetary nebulae (PNe) were expected to be filled with hot pressurized gas driving their expansion. ROSAT hinted at the presence of diffuse X-ray emission from these hot bubbles and detected the first sources of hard X-ray emission from their central ...
Martín A. Guerrero
doaj   +1 more source

Preface of “Asymmetric Planetary Nebulae 8e”

open access: yesGalaxies, 2022
Planetary nebulae (PNe) are the progeny of low- and intermediate-mass stars, at the exact time in their late evolution when they eject their hydrogen-rich envelopes and start their transition towards white dwarfs [...]
Martin A. Guerrero   +2 more
doaj   +1 more source

An HST Snapshot Survey of Proto-Planetary Nebulae Candidates: Two Types of Axisymmetric Reflection Nebulosities [PDF]

open access: yes, 1999
We report the results from an optical imaging survey of proto-planetary nebula candidates using the HST. We exploited the high resolving power and wide dynamic range of HST and detected nebulosities in 21 of 27 sources.
Bakker E. J.   +40 more
core   +4 more sources

Radio Continuum Spectra of Planetary Nebulae

open access: yesGalaxies, 2018
Radio continuum emission of planetary nebulae is a rich source of information about their structure and physical parameters. Although radio emission is well studied, planetary nebulae show higher spectral indices than expected for homogeneous sphere.
Marcin Hajduk   +6 more
doaj   +1 more source

The long-period binary central stars of the planetary nebulae NGC 1514 and LoTr 5 [PDF]

open access: yes, 2017
The importance of long-period binaries for the formation and evolution of planetary nebulae is still rather poorly understood, which in part is due to the lack of central star systems that are known to comprise such long-period binaries.
David Jones   +4 more
semanticscholar   +1 more source

Surveying Planetary Nebulae Central Stars for Close Binaries: Constraining Evolution of Central Stars Based on Binary Parameters

open access: yesGalaxies, 2018
The increase in discovered close binary central stars of planetary nebulae is leading to a sufficiently large sample to begin to make broader conclusions about the effect of close binary stars on common envelope evolution and planetary nebula formation ...
Todd Hillwig
doaj   +1 more source

Intracluster Planetary Nebulae [PDF]

open access: yesSymposium - International Astronomical Union, 2003
We review the progress of research on intracluster planetary nebulae (IPN). In the past five years, hundreds of IPN candidates have been detected in the Virgo and Fornax galaxy clusters and searches are also underway in poorer galaxy groups. From the observations to date, and applying the known properties of extragalactic planetary nebulae, the ...
openaire   +6 more sources

Nebular Spectroscopy: A Guide on H ii Regions and Planetary Nebulae [PDF]

open access: yes, 2017
We present a tutorial on the determination of the physical conditions and chemical abundances in gaseous nebulae. We also include a brief review of recent results on the study of gaseous nebulae, their relevance for the study of stellar evolution ...
M. Peimbert   +2 more
semanticscholar   +1 more source

X-ray Shaping of Planetary Nebulae

open access: yesGalaxies, 2018
The stellar winds of the central stars of planetary nebulae play an essential role in the shaping of planetary nebulae. In the interacting stellar winds model, the fast stellar wind injects energy and momentum, which are transferred to the nebular ...
Martín A. Guerrero
doaj   +1 more source

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