Results 71 to 80 of about 28,676 (218)

JWST Observations of the Ring Nebula (NGC 6720). III. A Dusty Disk around Its Central Star

The Astrophysical Journal
The planetary nebula NGC 6720, also known as the “Ring Nebula,” is one of the most iconic examples of nearby planetary nebulae whose morphologies present a challenge to our theoretical understanding of the processes that govern the deaths of most stars ...
Raghvendra Sahai, Griet Van de Steene, Peter A. M. van Hoof, Albert Zijlstra, Kevin Volk, Harriet L. Dinerstein, Michael J. Barlow, Els Peeters, Arturo Manchado, Mikako Matsuura, Jan Cami, Nick L. J. Cox, Isabel Aleman, Jeronimo Bernard-Salas, Nicholas Clark, Kay Justtanont, Kyle F. Kaplan, Patrick J. Kavanagh, Roger Wesson   +18 more
doaj   +1 more source

Planetary nebulae : getting closer to an unbiased binary fraction

, 2012
Why 80% of planetary nebulae are not spherical is not yet understood. The Binary Hypothesis states that a companion to the progenitor of the central star of a planetary nebula is required to shape the nebula and even for a planetary nebula to be formed ...
Bojicic, I., De Marco, O., Douchin, D., Frew, D. J., Hillwig, T. C., Jacoby, G. H., Jasniewicz, G., Parker, Q. A.   +7 more
core  

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

Role of Magma Oceans in Controlling Carbon and Oxygen of Sub-Neptune Atmospheres

The Astrophysical Journal
Most exoplanets with a few Earth radii are more inflated than bare-rock planets with the same mass, indicating a substantial volatile amount. Neither the origin of the volatiles nor the planet’s bulk composition can be constrained from the mass–radius ...
Chanoul Seo, Yuichi Ito, Yuka Fujii
doaj   +1 more source

He II Raman Scattered Line by Neutral Hydrogen in the Bipolar Platenary Nebula M2-9 [PDF]

Journal of Astronomy and Space Sciences, 2001
In the spectrum of the young bipolar planetary nebula M2-9 obtained from the 1.5 m telescope at the Cerro Tololo Inter-American Observatory, we detected the He~II feature at 6545 Å that are proposed to be formed via Raman scattering by atomic hydrogen ...
Hee-Won Lee, Young Woon Kang
doaj  

Testing the binary hypothesis for the formation and shaping of planetary nebulae

, 2012
There is no quantitative theory to explain why a high 80% of all planetary nebulae are non-spherical. The Binary Hypothesis states that a companion to the progenitor of a central star of planetary nebula is required to shape the nebula and even for a ...
Bojicic, I., De Marco, O., Douchin, D., Frew, D. J., Hillwig, T. C., Jacoby, G. H., Jasniewicz, G., Parker, Q. A.   +7 more
core  

A self-consistent stellar and 3D nebular model for Planetary Nebula IC418

, 2009
We present a coherent stellar and nebular model reproducing the observations of the Planetary Nebula IC418. We want to test whether a stellar model obtained by fitting the stellar observations is able to satisfactory ionize the nebula and reproduce the ...
Aller, Aller, Beck, Bloecker, Buerger, C. Morisset, Cristallo, Ercolano, Escalante, Ferland, Fitzpatrick, García-Segura, Gesicki, Gesicki, Gutíerrez-Moreno, Guzmán, Handler, Henry, Hillier, Hillier, Hyung, Karakas, Keenan, Krueger, L. Georgiev, Macfarlane, Marigo, Mendez, Mendez, Monteiro, Patriarchi, Pauldrach, Pottasch, Prinja, Richer, Schmutz, Schönberner, Sharpee, Sharpee, Sterling, Tayal, Tayal, Vassiliadis, Wilson   +43 more
core   +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

JWST/MIRI Study of the Enigmatic Mid-infrared Rings in the Planetary Nebula NGC 1514

The Astronomical Journal
While NGC 1514 is an elliptical, but complex, planetary nebula at optical wavelengths, it was discovered to have a pair of infrared-bright, axisymmetric rings contained within its faint outer shell during the course of the Wide-field Infrared Survey ...
Michael E. Ressler, Alba Aller, David Jones, Ryan M. Lau, Luis F. Miranda, Karen Willacy   +5 more
doaj   +1 more source