Results 21 to 30 of about 28,676 (218)
Herschel spectral-mapping of the Helix Nebula (NGC 7293): Extended CO photodissociation and OH+ emission [PDF]
, 2014 The Helix Nebula (NGC 7293) is the closest planetary nebulae. Therefore, it is an ideal template for photochemical studies at small spatial scales in planetary nebulae. We aim to study the spatial distribution of the atomic and the molecular gas, and the
Barlow, M. J. +15 more
core +3 more sources
Irradiation Investigation: Exploring the Molecular Gas in NGC 7293
Galaxies, 2020 Background: Many planetary nebulae retain significant quantities of molecular gas and dust despite their signature hostile radiation environments and energetic shocks.
Jesse Bublitz +7 more
doaj +1 more source
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 +4 more
doaj +1 more source
Three Stages in Evolution of the Object Th4-4
GalaxiesThe 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 +5 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. +6 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
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 +7 more
doaj +1 more source
The planetary nebula nature and properties of IRAS18197-1118
, 2014 IRAS18197-1118 is a stellar-like object that has been classified as a planetary nebula from its radio continuum emission and high [SIII]9532 to Paschen9 line intensity ratio, as derived from direct images.
Miranda, L. F. +3 more
core +1 more source
, 2009 We present intermediate resolution long-slit spectra and narrow-band Halpha, [NII] and [OIII] images of PM1-242, PM318 and PM1-333, three IRAS sources classified as possible planetary nebulae.
Acker +25 more
core +1 more source
A Compact X-ray Source and Possible X-ray Jets within the Planetary Nebula Menzel 3 [PDF]
, 2003 We report the discovery, by the Chandra X-ray Observatory, of X-ray emission from the bipolar planetary nebula Menzel 3. In Chandra CCD imaging, Mz 3 displays hot (3-6x10^6 K) gas within its twin, coaxial bubbles of optical nebulosity, as well as a ...
Adam Frank +10 more
core +3 more sources