Results 91 to 100 of about 169,425 (263)

Spitzer observations of planetary nebulae [PDF]

Proceedings of the International Astronomical Union, 2011
AbstractThe Spitzer Space Telescope has three science instruments (IRAC, MIPS, and IRS) that can take images at 3.6, 4.5, 5.8, 8.0, 24, 70, and 160 μm, spectra over 5–38 μm, and spectral energy distribution over 52–100 μm. The Spitzer archive contains targeted imaging observations for more than 100 PNe.
Chu, You-Hua, Chu, You-Hua
openaire   +4 more sources

A hydrodynamical study of multiple‐shell planetary nebulae [PDF]

, 2014
We present the result of a study on the expansion properties and internal kinematics of round/elliptical planetary nebulae of the Milky Way disk, the halo, and of the globular cluster M 15.
D. Schoênberner, R. Jacob, Holger Lehmann, G. Hildebrandt, M. Steffen, A. Zwanzig, C. Sandin, R. Corradi, R. Corradi   +8 more
semanticscholar   +1 more source

A primitive asteroid that lived fast and died young sampled by a xenolith in the Cold Bokkeveld CM2 carbonaceous chondrite

Meteoritics &Planetary Science, Volume 60, Issue 3, Page 464-483, March 2025.
Abstract Xenoliths in carbonaceous chondrites include lithologies that are unrepresented in the meteorite record and so are a rich source of information on asteroid diversity. Cold Bokkeveld is a CM2 regolith breccia that contains both hydrous and anhydrous lithic clasts. Here, we describe a hydrous clast with a fine‐grained rim.
Martin R. Lee, Cameron J. Floyd, Robin Haller, Sammy Griffin   +3 more
wiley   +1 more source

PAH formation in O-rich planetary nebulae [PDF]

, 2014
Polycyclic aromatic hydrocarbons (PAHs) have been observed in O-rich planetary nebulae towards the Galactic Bulge. This combination of oxygen-rich and carbon-rich material, known as dual-dust or mixed chemistry, is not expected to be seen around such ...
L. Guzman-Ramirez, E. Lagadec, D. Jones, A. Zijlstra, K. Gesicki   +4 more
semanticscholar   +1 more source

Iron and copper sulfides in asteroid (162173) Ryugu: Formation conditions and a comparison to the CI and CY chondrites

Meteoritics &Planetary Science, Volume 60, Issue 3, Page 506-528, March 2025.
Abstract JAXA's Hayabusa2 sample return mission visited the volatile‐rich carbonaceous (C‐type) asteroid (162173) Ryugu with the aim of ground‐truthing remote observations, returning a pristine sample from a C‐type asteroid, and strengthening links between asteroids and the meteorite collection. Here, we have conducted a systematic study of coarse (>10 
C. S. Harrison, A. J. King, R. H. Jones, S. S. Russell, T. Nakamura, H. Yurimoto, T. Noguchi, R. Okazaki, H. Yabuta, H. Naraoka, K. Sakamoto, S. Tachibana, T. Yada, M. Nishimura, A. Nakato, A. Miyazaki, K. Yogata, M. Abe, T. Okada, T. Usui, M. Yoshikawa, T. Saiki, S. Tanaka, F. Terui, S. Nakazawa, S. Watanabe, Y. Tsuda   +26 more
wiley   +1 more source

Molecular Envelopes of Planetary Nebulae and Proto-Planetary Nebulae [PDF]

International Astronomical Union Colloquium, 1994
As stars evolve up the asymptotic giant branch (AGB), they begin to lose mass at a high rate, and in the process they create extended circumstellar molecular envelopes. Since the transition from AGB to planetary nebula stages is of the order of 1000 yr, the remnant of such molecular envelopes should still be observable in pro to-planetary nebulae (PPN)
openaire   +2 more sources

Chemical abundances in Galactic planetary nebulae with Spitzer spectra [PDF]

, 2014
We present new low-resolution (R ∼ 800) optical spectra of 22 Galactic planetary nebulae (PNe) with Spitzer spectra. These data are combined with recent optical spectroscopic data available in the literature to construct representative samples of compact
D. A. García-Hernández, S. Górny
semanticscholar   +1 more source

The solar system Fe/Mg ratio

Meteoritics &Planetary Science, Volume 60, Issue 3, Page 529-543, March 2025.
Abstract Solar wind Fe and Mg fluences (atoms/cm2) were measured from Genesis collectors. Fe and Mg have similar first ionization potentials and solar wind Fe/Mg should equal the solar ratio. Solar wind Fe/Mg is a more valid measure of solar composition than CI chondrites and can be measured more accurately than spectroscopic photospheric abundances ...
D. S. Burnett, A. J. G. Jurewicz, D. S. Woolum, Y. Guan, V. S. Heber, R. Hervig, M. Humayun, K. D. McKeegan, L. R. Nittler, C. T. Olinger, D. B. Reisenfeld, J. Wang   +11 more
wiley   +1 more source

Molecular Hydrogen Microstructures in Planetary Nebulae

Galaxies, 2020
Molecular hydrogen (H 2 ) emission is commonly detected in planetary nebulae (PNe), specially in objects with bipolar morphologies. New studies showed that H 2 gas is also packed in microstructures embedded in PNe of any morphological type.
Stavros Akras, Denise R. Gonçalves, Gerardo Ramos-Larios, Isabel Aleman   +3 more
doaj   +1 more source

Catalog of Planetary Nebulae Detected by GALEX and Corollary Optical Surveys

The Astrophysical Journal Supplement Series, 2023
Planetary nebulae (PNs) consist of an ionized envelope surrounding a hot central star (CSPN) that emits mostly at ultraviolet (UV) wavelengths. UV observations, therefore, provide important information on both the CSPN and the nebula. We have matched the
M. A. Gómez-Muñoz, L. Bianchi, A. Manchado   +2 more
doaj   +1 more source