Results 21 to 30 of about 48,210 (191)

Lessons from the Ionised and Molecular Mass of Post-CE PNe

Galaxies, 2022
Close binary evolution is widely invoked to explain the formation of axisymmetric planetary nebulae after a brief common envelope phase. The evolution of the primary would be interrupted abruptly, its still quite massive envelope being fully ejected to ...
Miguel Santander-García, David Jones, Javier Alcolea, Valentín Bujarrabal, Roger Wesson   +4 more
doaj   +1 more source

Spectroscopy of Planetary Nebulae with Herschel: A Beginners Guide

Galaxies, 2018
A brief overview of the Herschel Space Telescope PACS and SPIRE spectrographs is given, pointing out aspects of working with the data products that should be considered by anyone using them.
Katrina Exter
doaj   +1 more source

An HST Snapshot Survey of Proto-Planetary Nebulae Candidates: Two Types of Axisymmetric Reflection Nebulosities [PDF]

ApJ, 528, 861, 1999
We report the results from an optical imaging survey of proto-planetary nebula candidates using the HST. We exploited the high resolving power and wide dynamic range of HST and detected nebulosities in 21 of 27 sources. All detected reflection nebulosities show elongation, and the nebula morphology bifurcates depending on the degree of the central star
arxiv   +1 more source

Evidence for the Disruption of a Planetary System During the Formation of the Helix Nebula

The Astronomical Journal, 2022
The persistence of planetary systems after their host stars evolve into their post-main-sequence phase is poorly constrained by observations. Many young white dwarf systems exhibit infrared excess emission and/or spectral absorption lines associated with
Jonathan P. Marshall, Steve Ertel, Eric Birtcil, Eva Villaver, Francisca Kemper, Henri Boffin, Peter Scicluna, Devika Kamath   +7 more
doaj   +1 more source

Planetary nebulae in M32 and the bulge of M31: Line intensities and oxygen abundances [PDF]

, 1998
We present spectroscopy of planetary nebulae in M32 and in the bulge of M31 that we obtained with the MOS spectrograph at the Canada-France-Hawaii Telescope. Our sample includes 30 planetary nebulae in M31 and 9 planetary nebulae in M32. We also observed one H II region in the disk of M31. We detected [O III]$\lambda$4363 in 18 of the planetary nebulae,
arxiv   +1 more source

Three Stages in Evolution of the Object Th4-4

Galaxies
The results of observations of the object Th4-4 in 1970–2024 showed that during this period the object went through several stages, when its characteristics corresponded to different classes of objects: Be star, symbiotic star and planetary nebula ...
Lyudmila Kondratyeva, Eduard Denissyuk, Saule Shomshekova, Inna Reva, Gauhar Aimanova, Maxim Krugov   +5 more
doaj   +1 more source

Close Binaries and the Abundance Discrepancy Problem in Planetary Nebulae

Galaxies, 2018
Motivated by the recent establishment of a connection between central star binarity and extreme abundance discrepancies in planetary nebulae, we have carried out a spectroscopic survey targeting planetary nebula with binary central stars and previously ...
R. Wesson, D. Jones, J. García-Rojas, H. M. J. Boffin, R. L. M. Corradi   +4 more
doaj   +1 more source

THE EMISSION-LINE DUSTY OBJECT IRAS 07080+0605, A LESS-EVOLVED EXAMPLE OF THE RED RECTANGLE

Odessa Astronomical Publications, 2020
The all-sky survey conducted by the InfraRed Astronomical Satellite (IRAS) in the 1980’s discovered many objects with infrared excesses whose nature has not been explored until recently.
S A. Khokhlov, A. S. Miroshnichenko, S. V, Zharikov, N. Manset, O. V. Zakhozhay, I. O. Bilinskyi, K. N. Grankin, A. V. kusakin, C. T. Omarov, R. I, Kokumbaeva, I. V. Reva, D. Korcakova, I. A. Usenko, A. K. Kuratova   +13 more
doaj   +1 more source

Spectral analysis of the binary nucleus of the planetary nebula Hen 2-428 – first results

Open Astronomy, 2018
Identifying progenitor systems for the double-degenerate scenario is crucial to check the reliability of type Ia supernovae as cosmological standard candles. Santander-Garcia et al. (2015) claimed that Hen 2-428 has a doubledegenerate core whose combined
Finch Nicolle L., Reindl Nicole, Barstow Martin A., Casewell Sarah L., Geier Stephan, Bertolami Marcelo M. Miller, Taubenberger Stefan   +6 more
doaj   +1 more source

Planetary Nebulae Populations in External Galaxies [PDF]

, 2011
This review highlights the properties of the planetary nebulae in external galaxies as tracers of light, of the stellar population properties, and of the distances and kinematics of the parent galaxies. Recent results on the kinematics of the outer regions in giant elliptical galaxies and on the luminosity specific PN numbers (the \alpha\ parameter) in
arxiv   +1 more source