Results 81 to 90 of about 53,151 (238)
Observations of planetary nebulae in the Galactic Bulge [PDF]
arXiv, 1999 High quality spectrophotometric observations of 30 Planetary Nebulae in the Galactic Bulge have been made. Accurate reddenings, plasma parameters, and abundances of He,O,N,S,Ar,Cl are derived. We find the abundances of O,S,Ar in the Planetary Nebulae in the Galactic Bulge to be comparable with the abundances of the Planetary Nebulae in the Disk, high
arxiv
Meteoritics &Planetary Science, Volume 60, Issue 3, Page 616-631, March 2025.Abstract Results of microanalysis study of NWA 869 meteorite, an ordinary chondrite, where silicates, Fe‐Ni alloys, and troilite are major constituents, are reported. The presented study of microtextures in metallic and sulfide grains provides information on processes occurring from the asteroid's accretion, through the impacts until cooling.
Paulina Skirak +4 more
wiley +1 more source
Abundances in Planetary Nebulae [PDF]
Symposium - International Astronomical Union, 1989 Good progress has been made since the last Symposium on the determination of planetary nebulae (PN) abundances. Notable features for modern abundance determinations include the availability of good collision strengths and transition probabilities (reviewed by C.
openaire +2 more sources
Measurements on Planetary Nebulae [PDF]
Symposium - International Astronomical Union, 1974 165 planetary nebulae south of +27° declination have been observed with the Parkes 64 m telescope. These nebulae were chosen to include most of those for which Hβ flux densities are available. Radio positions and flux densities (generally with probable errors of only a few millijanskies) obtained from the survey must represent the most reliable and ...
D. K. Milne, L. H. Aller
openaire +2 more sources
HI and CO Observations of Circumnebular Envelopes of Planetary Nebulae [PDF]
, 1994 21cm spectral-line and continuum observations of ten compact planetary nebulae have been made with the Very Large Array. Circumnebular atomic hydrogen is identified in the planetary nebulae SwSt1, M3-35, and possibly in Hu2-1. The possibility of an inverse correlation between the optical depth of circumnebular atomic hydrogen and the linear radius of ...
arxiv +1 more source
Shock‐heated graphite in three IAB iron meteorites—Implications on the formation of diamond
Meteoritics &Planetary Science, Volume 60, Issue 4, Page 744-756, April 2025.Abstract Iron meteorites, originating from the deepest parts of their parent bodies and separated during major break‐up events, surprisingly rarely contain diamonds despite experiencing similar pressure–temperature conditions as diamond‐bearing ureilites. In this study, graphite from three non‐magmatic IAB iron meteorites Canyon Diablo, Campo del Cielo,
Oliver Christ +7 more
wiley +1 more source
Distances of Planetary Nebulae [PDF]
Symposium - International Astronomical Union, 1993 One of the most fundamental physical parameter in astronomy is the distance to the objects we detect in the universe. For many classes of astronomical objects, accurate and proven methods have been developed to determine their distances. Such classes of objects include stars within ∼100 pc from the sun, binary stellar systems, variable stars, stellar ...
openaire +2 more sources
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
Classification of ISO SWS 01 spectra of proto-planetary nebulae: a search for precursors of planetary nebulae with [WR] central stars [PDF]
arXiv, 2002 We have analyzed ISO SWS 01 observations for 61 proto-planetary nebulae candidates and classified their spectra according to their dominant chemistry. On the basis of our classification and the more general classification of SWS 01 spectra by Kraemer et al.
arxiv
Oued Chebeika 002: A new CI1 meteorite linked to outer solar system bodies
Meteoritics &Planetary Science, EarlyView.Abstract CI1 chondrites are rare meteorites with high scientific value. In fact, they are the most chemically primitive meteorites and show evidence of intense parent‐body aqueous alteration. They also share strong similarities with samples from Ryugu and Bennu asteroids returned by the JAXA Hayabusa2 and NASA's OSIRIS‐REx missions.
J. Gattacceca +26 more
wiley +1 more source