Results 31 to 40 of about 26,504 (226)

Exploring how gender figures the identity trajectories of two doctoral students in observational astrophysics

open access: yesPhysical Review Physics Education Research, 2018
[This paper is part of the Focused Collection on Astronomy Education Research.] This paper presents the cases of two doctoral students in observational astrophysics whose circumstances and experiences led them on a career trajectory out of academic ...
Allison J. Gonsalves
doaj   +1 more source

Microstructural evidence for multiple generations of sulfide precipitation and impact‐induced thermal alteration under acidic conditions on Asteroid Ryugu

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Here we report on the microstructure and chemistry of sulfide minerals returned from asteroid (162173) Ryugu. We identify a unique sulfide population in particle A0016 composed of violarite (FeNi2S4), pyrite (FeS2), chalcopyrite (CuFeS2), pyrrhotite (Fe1‐xS), and pentlandite ([Fe,Ni]9S8).
M. C. Benner   +3 more
wiley   +1 more source

Crystallization of dmisteinbergite (hexagonal CaAl2Si2O8) from type B CAI analog melt

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Dmisteinbergite is a metastable polymorph of CaAl2Si2O8, which has been found in calcium−aluminum‐rich inclusions (CAIs) in chondrites, although anorthite is the predominant CaAl2Si2O8 phase in natural type B CAIs. The occurrence/absence of igneous dmisteinbergite would put tighter constraints on the thermal history of CAIs.
Yasuaki Tsuruoka   +6 more
wiley   +1 more source

The new worlds observer: The astrophysics strategic mission concept study

open access: yesEPJ Web of Conferences, 2011
We present some results of the Astrophysics Strategic Mission Concept Study for the New Worlds Observer (NWO). We show that the use of starshades is the most effective and affordable path to mapping and understanding our neighboring planetary systems, to
Cash W.
doaj   +1 more source

Directionally Effect Observation in Topographical Site-Effects at Feden-Sema Range (Guelma-Northern Algeria) from Ambient Vibration [PDF]

open access: yesMATEC Web of Conferences
The Eocene Feden-Sema Range is a topographical structure located in the complex area of Mechtat El-Ababsia (Guelma) characterized by topographical site effects from an experimental investigation using earthquake and ambient vibration.
Layadi Khalissa   +4 more
doaj   +1 more source

Nature, origin, and phosphorylation potential of the phosphorus/sulfur‐bearing nanoscale multiphasic assemblages in the CM chondrites Murchison and Murray

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Carbonaceous chondrites contain phosphorus, whose speciation and thus history remain to be investigated. Phosphorus/sulfur‐bearing assemblages have been reported in carbonaceous CM chondrites, but there is no consensus about their exact compositions and origins.
Valentine Megevand   +4 more
wiley   +1 more source

Image et mesure : deux cultures aux origines de l’astrophysique française

open access: yesCahiers François Viète, 2006
In the commission preparing the 1874 transit of Venus, debates about the choice of photographic techniques are illustrative of the stakes that would come to characterize the beginning of astronomy in France over the following decades.
Stéphane Le Gars
doaj   +1 more source

The first discovery of a shocked, metasomatised CV3 chondrule‐fragment in a (Al,Cu)‐bearing micrometeorite

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract We report the discovery of the second (Al,Cu)‐alloy–bearing micrometeorite, FB‐A2, recovered from Mount Gariglione (southern Italy), representing the sixth such occurrence worldwide. Although chondritic in nature, FB‐A2 differs markedly from previously described microspherules.
Giovanna Agrosì   +6 more
wiley   +1 more source

Hot super-Earths stripped by their host stars

open access: yesNature Communications, 2016
Theory predicts a deficit of super-Earth sized planets, which orbit close to their host star. Here, Lundkvist et al. use data from the NASA Kepler mission to show that this deficit is also seen in observations, thereby providing new insight into ...
M. S. Lundkvist   +28 more
doaj   +1 more source

Characterization of coesite‐bearing impact melt glass from the Hapcheon crater, Korea: Trimodal phase architecture, shock metamorphism, and implications for 40Ar/39Ar geochronology

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract We present the first micrometer‐scale, phase‐resolved compositional characterization of impact melt glass from the Hapcheon crater (~1.4 km apparent diameter), the first confirmed impact structure on the Korean Peninsula, integrating EPMA‐WDS (5 μm spot), confocal Raman spectroscopy (<1 μm spot), XRD, and 40Ar/39Ar step‐heating geochronology ...
Jin‐Young Lee   +2 more
wiley   +1 more source

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