Results 91 to 100 of about 174,483 (232)

Ionization correction factors for planetary nebulae – I. Using optical spectra [PDF]

, 2014
We compute a large grid of photoionization models that covers a wide range of physical parameters and is representative of most of the observed PNe. Using this grid, we derive new formulae for the ionization correction factors (ICFs) of He, O, N, Ne, S ...
G. Delgado-Inglada, C. Morisset, Gra.zyna Stasi'nska Instituto de Astronom'ia, Mexico., Luth, O. Meudon, France.   +6 more
semanticscholar   +1 more source

Natural Hydrogen: A Mini‐Review Unveiling Its Potential as a Key to Sustainable Future for Energy

EcoEnergy, Volume 3, Issue 4, December 2025.
This mini‐review summarizes natural hydrogen's formation mechanisms, exploration progress, and potential to drive global energy transition toward sustainability. ABSTRACT As the global energy shortage challenge and transition continues, greater attention is being drawn to natural hydrogen, a clean and high‐potential energy source.
Yuanming Gao, Silin Liu, Rong Chen, Zongyi Li, Xuezhen Wu, Wen Ma, Yuzhuo Luo, Yanhe Wang, Xi Ding, Xiaoxin Li, Henrietta W. Langmi, Nicholas M. Musyoka, Lei Jiang, Rodolfo Christiansen, Guo‐Ming Weng   +14 more
wiley   +1 more source

Evolution of Terrestrial Planetary Bodies and Implications for Habitability

Reviews of Geophysics, Volume 63, Issue 4, December 2025.
Abstract The terrestrial planetary bodies of our solar system—Mercury, Venus, Earth, and Mars—share a common origin through nebular accretion and early magma ocean differentiation, yet they diverged significantly in geological evolution, tectonic regimes, and habitability.
Peter A. Cawood, Eva E. Stüeken, Priyadarshi Chowdhury, Chris J. Hawkesworth, Jacob A. Mulder   +4 more
wiley   +1 more source

Comparison of Two Methods for Determination of Rhenium and Platinum‐Group Elements in Meteorites Using On‐Line and Off‐Line Matrix Separation Modes

Geostandards and Geoanalytical Research, Volume 49, Issue 4, Page 737-750, December 2025.
Key Points PEEK tubing has been observed to adsorb Pd and Pt ions, resulting in significantly reduced recoveries of Pd and Pt elements. HPA‐S provides a more effective dissolution for meteorite samples than Carius tube digestion, resulting in higher mass fractions for PGE.
Yuling Zeng, Guiqin Wang, Thomas C. Meisel   +2 more
wiley   +1 more source

The Qingzhen reaction, a fine‐grained mineral assemblage associated with djerfisherite in some EH3 chondrites: Alteration on the EH parent body

Meteoritics &Planetary Science, Volume 60, Issue 12, Page 2913-2934, December 2025.
Abstract Enstatite chondrites formed under extremely reducing conditions in the protoplanetary disk. They are derived from two or more parent bodies, EH and EL, and both EH and EL groups contain petrologic type 3–6 samples. The rare lithophile‐ and halogen‐bearing sulfide, djerfisherite, occurs in low abundance in enstatite chondrites, most frequently ...
Peter Mc Ardle, Rhian H. Jones, Luke Daly, Romain Tartèse, Patricia L. Clay, Brian O'Driscoll, Ray Burgess, William Smith, Colin How, Lewis Hughes   +9 more
wiley   +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

New Arabic Records From Cairo on Supernovae 1181 and 1006

Astronomische Nachrichten, Volume 346, Issue 9, November 2025.
ABSTRACT The remnant of the historical supernova SN 1181 is under discussion: While the previously suggested G130.7+3.1 (3C58) appears too old (3000–5000 year), the unusual star IRAS00500+6713 with a surrounding nebula (Pa‐30) has an expansion age not inconsistent with a SN Iax explosion in ad 1181 under the assumption that neither acceleration nor ...
J. G. Fischer, H. Halm, R. Neuhäuser, D. L. Neuhäuser   +3 more
wiley   +1 more source

Whither or Wither the Sulfur Anomaly in Planetary Nebulae?

The Astrophysical Journal Letters
We present a thorough investigation of the long-standing sulfur anomaly enigma. Our analysis uses chemical abundances from the most extensive data set available for 126 planetary nebulae (PNs) with improved accuracy and reduced uncertainties from a 10° ×
Shuyu Tan, Quentin A. Parker
doaj   +1 more source

On the Origin of Morphological Structures of Planetary Nebulae

Galaxies, 2018
We suggest that most of the mass in planetary nebulae (PNe) resides in the equatorial region and the spherical envelope and the optically bright lobes of PNe are in fact low-density cavities cleared out by fast outflows and photoionized by UV photons ...
Sun Kwok
doaj   +1 more source

New Close Binary Central Stars of Planetary Nebulae from Gaia DR3 Epoch Photometry. [PDF]

Res Notes AAS, 2022
Chornay N, Walton NA.
europepmc   +1 more source