Results 11 to 20 of about 4,999 (221)

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   +2 more sources

Planetary Nebulae Research: Past, Present, and Future

open access: yesGalaxies
We review the evolution of our understanding of the planetary nebulae phenomenon and their place in the scheme of stellar evolution. The historical steps leading to our current understanding of central star evolution and nebular formation are discussed ...
Sun Kwok
doaj   +3 more sources

A Preferred Orientation Angle for Bipolar Planetary Nebulae [PDF]

open access: yesGalaxies, 2020
We present preliminary results from measuring Galactic orientation angles of 766 elliptical and bipolar Planetary Nebulae (PNe) in the Hong Kong/Australian Astronomical Observatory/Strasbourg Observatory H-alpha Planetary Nebula research platform and ...
Andreas Ritter, Quentin A. Parker
doaj   +2 more sources

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   +2 more sources

Numerical Models of Planetary Nebulae with Different Episodes of Mass Ejection: The Particular Case of HuBi 1

open access: yesThe Astrophysical Journal, 2023
We have studied the evolution of HuBi 1–like planetary nebulae, considering several stages of mass injection. We have carried out numerical ionization+1D hydrodynamics+atomic/ionic rate models with our code Coral1d to reproduce planetary nebulae that ...
Ary Rodríguez-González   +6 more
doaj   +1 more source

The dynamics of Planetary Nebulae [PDF]

open access: yesSymposium - International Astronomical Union, 1997
In this review we focus on new observations and theory that directly pertain to understanding the hydrodynamic evolution of planetary nebulae (PNe). The recent history of the field lead us to break the review into two parts, macroscopic and microscopic structures, since both the size scales and the dominant physics appear to cleave nicely into more-or ...
Bruce Balick, Adam Frank
openaire   +1 more source

When the Stars Align: A 5σ Concordance of Planetary Nebulae Major Axes in the Center of Our Galaxy

open access: yesThe Astrophysical Journal Letters, 2023
We report observations of a remarkable major axes alignment nearly parallel to the Galactic plane of 5 σ significance for a subset of bulge “planetary nebulae” (PNe) that host, or are inferred to host, short-period binaries. Nearly all are bipolar. It is
Shuyu Tan   +4 more
doaj   +1 more source

Infrared Observations of Planetary Nebulae and Related Objects

open access: yesGalaxies, 2020
In this paper, I present how near and mid-infrared observations can be used for the study of planetary nebulae and related objects. I present the main observing techniques, from the ground and space, highlighting main differences and how they can be ...
Eric Lagadec
doaj   +1 more source

Integral Field Spectroscopy of Planetary Nebulae with MUSE

open access: yesGalaxies, 2020
The Multi-Unit Spectroscopic Explorer (MUSE) is a large integral field unit mounted on the ESO Very Large Telescope. Its spatial (60 arcsecond field) and wavelength (4800–9300Å) coverage is well suited to detailed imaging spectroscopy of extended ...
Jeremy R. Walsh, Ana Monreal-Ibero
doaj   +1 more source

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

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