Results 21 to 30 of about 23,039 (206)

On the Age of Galactic Bulge CSPNe: Too Young and Complicated?

open access: yesGalaxies, 2020
We present preliminary results of our study of a small sample of planetary nebulae in the Galactic Bulge for which high-angular resolution Hubble Space Telescope imaging is available.
Foteini Lykou   +2 more
doaj   +1 more source

Planetary Nebulae as Sources of Chemical Enrichment of the Galaxy

open access: yesFrontiers in Astronomy and Space Sciences, 2022
During the late asymptotic giant branch (AGB) phase of stellar evolution, the element carbon is created through the triple-α nuclear reaction. This is followed by the synthesis of other heavy elements via neutron capture in the core and the dredge-up of ...
Sun Kwok, Sun Kwok
doaj   +1 more source

MULTI-STAGES OPTIMIZED PHOTOIONIZATION MODELLING OF PLANETARY NEBULA LMC SMP-21

open access: yesOdessa Astronomical Publications, 2012
The new approximation expression for the representation of gas density distribution in planetary nebulae envelopes was proposed. The new multi-stages method for the caclulation of the chemical composition and physical parameters of planetary nebulae ...
B. Ya. Melekh   +5 more
doaj   +1 more source

A search for magnetic fields on central stars in planetary nebulae [PDF]

open access: yes, 2014
One of the possible mechanisms responsible for the panoply of shapes in planetary nebulae is the presence of magnetic fields that drive the ejection of ionized material during the proto-planetary nebula phase. Therefore, detecting magnetic fields in such
Corradi, R. L. M.   +4 more
core   +1 more source

(Sub)mm-Wavelength Observations of Pre-Planetary Nebulae and Young Planetary Nebulae

open access: yesGalaxies, 2020
This is a non-comprehensive review of observations of pre-Planetary Nebulae (pPNe) and young Planetary Nebulae (yPNe) at (sub)mm-wavelengths, a valuable window for probing multi-phased gas and dust in these objects.
Carmen Sánchez Contreras
doaj   +1 more source

The Planetary Nebulae Spectrograph: the green light for Galaxy Kinematics [PDF]

open access: yes, 2002
Planetary nebulae are now well established as probes of galaxy dynamics and as standard candles in distance determinations. Motivated by the need to improve the efficiency of planetary nebulae searches and the speed with which their radial velocities are
A. J. Romanowsky   +19 more
core   +4 more sources

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

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

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

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

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