Results 1 to 10 of about 27,938 (255)
Nebula-Relay Hypothesis: The Chirality of Biological Molecules in Molecular Clouds
Frontiers in Astronomy and Space Sciences, 2022 The chiral puzzle of biological molecules is thought to be closely related to the origin of life and is still a mystery so far. Previously, we proposed a new model on the origin of life, Nebula-Relay hypothesis, which assumed that the life on Earth ...
Lei Feng, Lei Feng, Lei Feng
doaj +1 more source
The 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
PHL 932: When Is a Planetary Nebula Not a Planetary Nebula? [PDF]
Publications of the Astronomical Society of Australia, 2010 AbstractThe emission nebula around the subdwarf B (sdB) star PHL 932 is currently classified as a planetary nebula (PN) in the literature. Based on a large body of multi-wavelength data, both new and previously published, we show here that this low-excitation nebula is in fact a small Strömgren sphere (Hii region) in the interstellar medium around this
Parker, Quentin A. +3 more
openaire +5 more sources
The Effect of Superpositions on the Planetary Nebula Luminosity Function
The Astrophysical Journal, 2023 Planetary nebula (PN) surveys in systems beyond ∼10 Mpc often find high-excitation, point-like sources with [O iii ] λ 5007 fluxes greater than the apparent bright-end cutoff of the planetary nebula luminosity function (PNLF).
Owen Chase +3 more
doaj +1 more source
The Astrophysical Journal, 1987 We report the first detection of millimeter CO emission in two highly evolved planetary nebulae: NGC 6720 and NGC 7293. The CO is a useful probe of the structure and kinematics of the molecular gas in the nebulae, and provides an estimate of the mass of material which remains un-ionized by the central star.
A. P. Healy, P. J. Huggins
openaire +2 more sources
WORKPLANS: Workshop on Planetary Nebula Observations
Galaxies, 2020 This workshop is the second of the WORKPLANS series, which we started in 2016. The main goal of WORKPLANS is to build up a network of planetary nebulae (PNe) experts to address the main open questions in the field of PNe research.
Isabel Aleman +4 more
doaj +1 more source
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
Shaping of Planetary Nebulae by Exoplanets
Galaxies, 2020 (1) Background: We investigate the hypothesis that exoplanet engulfment can help explain the observed non-spherical planetary nebula population, as a complementary shaping mechanism to the binary hypothesis.
Nicola Keaveney +2 more
doaj +1 more source
M 1–92 Revisited: New Findings and Open Questions: New NOEMA Observations of Minkowski’s Footprint
Galaxies, 2022 PN M 1–92, also known as Minkowski’s Footprint, is a textbook example of a massive pre-planetary nebula. It presents all the characteristics of this type of source: non-spherical symmetry (bipolar cylindrical symmetry in this case), high-velocity gas ...
Javier Alcolea +7 more
doaj +1 more source
The influence of planetary nebula gas density fluctuations to its emission line spectra
Вісник Астрономічної школи, 2000 The set of spheric-simmetrical photoionization models of planetary nebula luminescence for different radial gas density distributions for central stars temperatures T = 50000 K and T = 100000 K was created.
N. V. Gavrilova, N. L. Tishko
doaj +1 more source