Results 31 to 40 of about 4,999 (221)

Chemical Synthesis in the Circumstellar Environment

open access: yesGalaxies
We discuss the spectral distinctions between B[e] stars and compact planetary nebulae. The differentiation between proto-planetary nebulae, transition objects between the asymptotic giant branch and planetary nebulae, and reflection nebulae in binary ...
Sun Kwok
doaj   +1 more source

Mining of the Milky Way Star Archive Gaia-DR2. Searching for Binary Stars in Planetary Nebulae

open access: yesProceedings, 2020
The aim of this work is to search for binary stars associated to planetary nebulae (ionized stellar envelopes in expansion), by mining the astronomical archive of Gaia DR2, that is composed by around 1.7 billion stellar sources.
Iker González-Santamaría   +4 more
doaj   +1 more source

Emission-Line Fluxes of Northern Planetary Nebulae [PDF]

open access: yes, 2015
We present long slit spectrophotometric emission line fluxes of bright and extended (
ATALAY, BETÜL   +7 more
core   +2 more sources

Planetary Nebulae Embryo after a Common Envelope Event

open access: yesGalaxies, 2018
In the centers of some planetary nebulae are found close binary stars. The formation of those planetary nebulae was likely through a common envelope event, which transformed an initially-wide progenitor binary into the currently observed close binary ...
Natalia Ivanova, Jose L. A. Nandez
doaj   +1 more source

Planetary Nebulae and the Ionization of the Interstellar Medium in Galaxies

open access: yesFrontiers in Astronomy and Space Sciences, 2022
We discuss the role of planetary nebulae and their progeny in galaxy context in terms of ionization of the galaxy interstellar medium. This regards ionized gas outside the disk of spiral galaxies, the diffuse ionized medium in spiral galaxies, and the ...
Grażyna Stasińska   +2 more
doaj   +1 more source

Current Unsolved Problems in Planetary Nebulae Research

open access: yesGalaxies
While there has been significant progress in our understanding of the origin and evolution of planetary nebulae in the last 50 years, there remain several unsolved problems.
Sun Kwok   +7 more
doaj   +1 more source

The morphology of dust emission in Planetary Nebulae and proto-Planetary Nebulae [PDF]

open access: yesSymposium - International Astronomical Union, 1997
This review covers recent results from ground based mid-infrared (mid–IR; 8–25μm) imaging of thermal dust emission. The mid–IR images of proto–PNe show evidence for axially symmetric superwinds. In young PNe, the dust appears to be well mixed with the gas in the ionized gas regions.
openaire   +1 more source

Analysis of Multiple Shell Planetary Nebulae Based on HST/WFPC2 Extended 2D Diagnostic Diagrams

open access: yesGalaxies, 2018
The investigation of gaseous nebulae, emitting in forbidden lines, is often based extensively on diagnostic diagrams. The special physics of these lines often allows for disentangling with a few line ratios normally coupled thermodynamic parameters like ...
Daniela Barría, Stefan Kimeswenger
doaj   +1 more source

From Flybys to Sample Return: A Review of Space Probes and Robotic Sampling Technologies for Small Bodies

open access: yesJournal of Field Robotics, EarlyView.
ABSTRACT As a crucial puzzle piece of deep space exploration, exploring small bodies can provide significant scientific insights and valuable mineral resources. Unlike missions to the Moon and Mars, small‐body missions pose distinct technical challenges, including communication delays, weak gravity, and uncertain environments. This paper reviews a full
Xin Zhang   +3 more
wiley   +1 more source

Imaging polarimetry of planetary and proto-planetary nebulae [PDF]

open access: yes, 1997
Optical imaging polarimetry has been performed on a small sample of objects which are associated with that stage of stellar evolution occurring between the Asymptotic Giant Branch and full Planetary Nebula. Three such systems are considered, specifically,
Bowlzer, S.L., Bowlzer, S. L.
core  

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