Results 11 to 20 of about 23,039 (206)
Spherical Planetary Nebulae [PDF]
Astronomy & Astrophysics, 2001 By examining their mass loss history and their distribution in the galaxy I argue that spherical planetary nebulae (PNe) form a special group among all planetary nebulae. The smooth surface brightness of most spherical PNe suggests that their progenitors
Allen +15 more
core +5 more sources
X-ray Observations of Planetary Nebulae since WORKPLANS I and Beyond
Galaxies, 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
Radio Continuum Spectra of Planetary Nebulae
Galaxies, 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
Annual Review of Astronomy and Astrophysics, 1993 The progress in the search for proto-planetary nebulae (PPN) in the last 5 years is reviewed. An observational definition of PPN is developed and a list of current PPN candidates is given. The optical, infrared, and radio properties of PPN are summarized and compared with theoretical models.
openaire +2 more sources
Galaxies, 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
Preface of “Asymmetric Planetary Nebulae 8e”
Galaxies, 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
Interpretation of the expansion law of planetary nebulae [PDF]
, 2006 We reproduce the expansion velocity--radius ($V_{\rm{exp}}$--$R_{\rm{n}}$) relation in planetary nebulae by considering a simple dynamical model, in order to investigate the dynamical evolution and formation of planetary nebulae.
Fukue, Tsubasa +2 more
core +3 more sources
X-ray Shaping of Planetary Nebulae
Galaxies, 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
Stellar wind bubbles around WR and [WR] stars [PDF]
, 2002 We study the dynamics of stellar wind bubbles around hydrogen-deficient stars using numerical simulations with time- and ion dependent cooling. We consider two types of hydrogen-deficient stars, massive WR stars, producing Ring Nebulae, and low mass [WR]
Abbott +37 more
core +3 more sources
The Formation of Fullerenes in Planetary Nebulae
Galaxies, 2018 In the last decade, fullerenes have been detected in a variety of astrophysical environments, with the majority being found in planetary nebulae. Laboratory experiments have provided us with insights into the conditions and pathways that can lead to ...
Jan Cami +4 more
doaj +1 more source