Results 71 to 80 of about 6,433 (179)

Third-dredge-up oxygen in planetary nebulae [PDF]

, 2000
The planetary nebulae He 2-436 and Wray 16-423 in the Sagittarius dwarf galaxy appear to result from nearly twin stars, except that third-dredge-up carbon is more abundant in He 2-436. A thorough photoionization-model analysis implies that ratios Ne/O, S/
Dudziak, G., Pequignot, D., Walsh, J. R., Zijlstra, A. A.   +3 more
core   +1 more source

Close Binary (and Pulsating) Nuclei of Planetary Nebulae [PDF]

International Astronomical Union Colloquium, 1979
Close-binary central stars of planetary nebulae are of interest to participants in this Colloquium because of recent suggestions that the cataclysmic binaries, containing a white dwarf and a lower-main-sequence star, may be descended from such objects (e.g.
openaire   +1 more source

A Raman Spectroscopic Study of Lightning‐Induced Glass Produced From Five Mineral Phases

Earth and Space Science, Volume 11, Issue 5, May 2024.
Abstract Lightning‐induced volcanic spherules (LIVS) are glasses produced by the rapid melting and solidification of molten volcanic ash grains. High temperatures generated by lightning will alter the physical and chemical properties of minerals exposed to the discharge.
T. W. Woods, K. Genareau, C. Park
wiley   +1 more source

Ultraviolet observations of close-binary and pulsating nuclei of planetary nebulae; Winds and shells around low-mass supergiants; The close-binary nucleus of the planetary nebula HFG-1; A search for binary nuclei of planetary nebulae; UV monitoring of irregularly variable planetary nuclei; and The pulsating nucleus of the planetary nebula Lo 4 [PDF]

A brief summary of the research highlights is presented. The topics covered include the following: binary nuclei of planetary nebulae; other variable planetary nuclei; low-mass supergiants; and other IUE-related ...
Bond, Howard E.
core   +1 more source

Binary central stars of planetary nebulae [PDF]

, 2006
This paper reviews our knowledge on binary central stars of planetary nebulae and presents some personal opinions regarding their evolution. Three types of interactions are distinguished: type I, where the binary companion induces the mass loss; type II,
Zijlstra, Albert A.
core   +1 more source

The amino acid and polycyclic aromatic hydrocarbon compositions of the promptly recovered CM2 Winchcombe carbonaceous chondrite

Meteoritics &Planetary Science, Volume 59, Issue 5, Page 1101-1130, May 2024.
Abstract The rapid recovery of the Winchcombe meteorite offers a valuable opportunity to study the soluble organic matter (SOM) profile in pristine carbonaceous astromaterials. Our interests in the biologically relevant molecules, amino acids—monomers of protein, and the most prevalent meteoritic organics—polycyclic aromatic hydrocarbons (PAHs) are ...
Queenie H. S. Chan, Jonathan S. Watson, Mark A. Sephton, Áine C. O'Brien, Lydia J. Hallis   +4 more
wiley   +1 more source

Hot bubbles of planetary nebulae with hydrogen-deficient winds - II. Analytical approximations with application to BD+30$^\circ$3639

, 2018
The first high-resolution X-ray spectroscopy of the planetary nebula BD+30$^\circ$3639 allowed to study X-ray emitting "hot bubbles" (HBs) of planetary nebulae in unprecedented detail.
Heller, René, Jacob, Ralf, Schönberner, Detlef, Steffen, Matthias   +3 more
core   +1 more source

Winchcombe: An example of rapid terrestrial alteration of a CM chondrite

Meteoritics &Planetary Science, Volume 59, Issue 5, Page 988-1005, May 2024.
Abstract Winchcombe is a CM chondrite that fell in England on February 28, 2021. Its rapid retrieval was well characterized. Within two polished sections of Winchcombe, terrestrial phases were observed. Calcite and calcium sulfates were found in a sample recovered from a field on March 6, 2021, and halite was observed on a sample months after its ...
Laura E. Jenkins, Martin R. Lee, Luke Daly, Ashley J. King, Cameron J. Floyd, Pierre‐Etienne Martin, Natasha V. Almeida, Matthew J. Genge   +7 more
wiley   +1 more source

Infrared spectra of WC10 planetary nebulae nuclei [PDF]

The 5.2 to 8.0 micron spectra are presented for two planetary nebulae nuclei Hen1044 (He2-113) and CPD-56 8032. The unidentified infrared (UIR) emission bands at 6.2 microns, 6.9 microns, 7.7 microns are present in the spectra of Hen1044 and in CPD-56 ...
Allamandola, L. J., Bregman, J. D., Cohen, M., Rank, D. M., Tielens, G. G. M., Witteborn, F. C., Wooden, D. H.   +6 more
core   +1 more source

The Mid-Infrared [SIV]/[NeII] versus [NeIII]/[NeII] Correlation

, 2008
The mid-infrared ratio [NeIII]15.6mum/[NeII]12.8mum is a strong diagnostic of the ionization state of emission line objects, due to its use of only strong neon emission lines only weakly affected by extinction.
Achtermann, Armus, Bas Nefs, Beirão, Bernard-Salas, Bernhard Brandl, Brandl, Brandl, Brent Groves, Dale, De Graauw, Deo, Dopita, Draine, Engelbracht, Farrah, Giveon, Gordon, Houck, Kessler, Lebouteiller, Li, Rubin, Rubin, Smith, Snijders, Sturm, Thornley, Verma, Werner, Wu   +30 more
core   +1 more source