Results 71 to 80 of about 174,483 (232)

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

Evaluating Investment in Space Programs: A Case for Theoretical Pluralism

Financial Accountability &Management, Volume 42, Issue 1, Page 19-35, February 2026.
ABSTRACT A perennial question repeatedly asked since the early Mercury (USA) and Salyut (then Soviet Union) space programs has been variations on the theme of “how can the cost of space exploration be justified?” This question—which in broad terms constitutes the research question considered in this paper—continues to be directed toward space agencies ...
Basil P. Tucker, Hank C. Alewine
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

Formation of Asteroid (16) Psyche by a Giant Impact

Journal of Geophysical Research: Planets, Volume 131, Issue 1, January 2026.
Abstract Asteroid (16) Psyche is the largest likely metal‐rich asteroid in the Solar System and the target of the NASA Psyche mission. The mission aims to determine whether the asteroid is the core of a differentiated planetesimal that lost its mantle via a giant impact.
Saverio Cambioni, Benjamin P. Weiss, Namya Baijal, Robert Melikyan, Erik Asphaug, John B. Biersteker, Richard P. Binzel, William F. Bottke, Samuel W. Courville, Linda T. Elkins‐Tanton, David J. Lawrence, José M. G. Merayo, Carol A. Raymond, Mark A. Wieczorek, Maria T. Zuber   +14 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

DUSTY DISKS AROUND CENTRAL STARS OF PLANETARY NEBULAE [PDF]

, 2014
Only a few percent of cool, old white dwarfs (WDs) have infrared excesses interpreted as originating in small hot disks due to the infall and destruction of single asteroids that come within the star's Roche limit.
G. Clayton, O. De Marco, J. Nordhaus, Joel D. Green, T. Rauch, K. Werner, Y. Chu   +6 more
semanticscholar   +1 more source

Rural Root Shock

Antipode, Volume 58, Issue 1, January 2026.
Abstract This article expands social psychiatrist Mindy Fullilove's characterisation of US postwar urban community root shock in time and space. We explore the impacts of land dispossession and population displacement on Black farming communities and their health from colonial origins on.
Robert G. Wallace, Elsa Calderon, M. Jahi Johnson‐Chappell, Garrett Graddy‐Lovelace, Khaliah D. Pitts, Sam Sharpe   +5 more
wiley   +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

A search for magnetic fields on central stars in planetary nebulae [PDF]

, 2014
Departamento de Astrofisica, Universidad de La Laguna, E-38205 La Laguna, Tenerife, SpainReceived To be inserted later, accepted To be inserted laterABSTRACTContext.One of the possible mechanisms responsible for the panoply of shapes in planetary nebulae
F. Leone, R. Corradi, M. Gonz'alez, A. Ramos, R. M. Sainz   +4 more
semanticscholar   +1 more source

Modeling enstatite chondrites: Reduced rocks with a pinch of oxidized material (affected by varying H2O(g)) derived from planetesimals shocked during the epoch of giant–planet migration

Meteoritics &Planetary Science, Volume 61, Issue 1, Page 122-139, January 2026.
Abstract The O‐, N‐, Mo‐, Ru‐, Os‐, Cr‐, Ti‐, Ni‐, Fe‐, Nd‐, Ca‐, Zn‐, Sr‐, and Mg‐isotopic compositions of enstatite chondrites are essentially identical to those of the Earth and Moon. These correspondences suggest enstatite chondrites formed at ≈1 AU as the only known chondrite groups that accreted in the vicinity of a major planet. Bulk Earth has a
Alan E. Rubin
wiley   +1 more source