Astrophysics - solar and stellar astrophysics

Results 21 to 30 of about 2,040 (178)

Astrophysical uncertainties on stellar microlensing constraints on multisolar mass primordial black hole dark matter [PDF]

Physical Review D, 2017
There has recently been interest in multi-Solar mass Primordial Black Holes (PBHs) as a dark matter (DM) candidate. There are various microlensing, dynamical and accretion constraints on the abundance of PBHs in this mass range. Taken at face value these constraints exclude multi-Solar mass PBHs making up all of the DM for both delta-function and ...
openaire +4 more sources

Discovery of a dormant 33 solar-mass black hole in pre-release Gaia astrometry [PDF]

Astronomy & Astrophysics
Gravitational waves from black-hole (BH) merging events have revealed a population of extra-galactic BHs residing in short-period binaries with masses that are higher than expected based on most stellar evolution models -- and also higher than known ...
Gaia Collaboration P. Panuzzo +413 more
semanticscholar +1 more source

JWST Imaging of the Closest Globular Clusters—VI. The Lowest‐Mass Objects in M 4 and the Galactic Bulge

Astronomische Nachrichten, EarlyView.
ABSTRACT We present James Webb Space Telescope observations of M 4—the closest globular cluster—that probe the lower Main Sequence down to the hydrogen‐burning limit. The unveiled stellar sequence reaches much fainter luminosities than previously possible, revealing a few extremely red objects that are consistent with brown dwarfs as cool as Teff∼1000K$
L. R. Bedin +10 more
wiley +1 more source

Modelling Thomson Scattering in a Hydrogen Plasma at Stellar Interior Conditions Using the Hypernetted‐Chain Approach

Contributions to Plasma Physics, EarlyView.
ABSTRACT Under the extreme conditions found in small stars, where electron degeneracy and Coulomb coupling are significant, accurate modeling of Thomson scattering is crucial for determining opacity, a primary quantity for stellar energy transport.
Samuel Schumacher +8 more
wiley +1 more source

Insights on the volcanic and impact histories of the lunar nearside from the petrology, geochemistry, and geochronology of the Calcalong Creek lunar regolith breccia meteorite

Meteoritics &Planetary Science, Volume 60, Issue 3, Page 392-421, March 2025.
Abstract The Calcalong Creek lunar meteorite is a regolith breccia with a lithologically diverse array of clasts set in a glassy, highly vesicular matrix. Here, we present a comprehensive new analysis of the meteorite. Comparisons to remote sensing data, lunar sample lithologies, and lunar sample ages indicate that it was likely sourced from regolith ...
B. H. Oliveira +6 more
wiley +1 more source

Using X‐ray computed microtomography (μCT) to determine subsample‐specific cosmogenic noble gas production rates of E (enstatite) chondrites

Meteoritics &Planetary Science, Volume 60, Issue 3, Page 442-463, March 2025.
Abstract Cosmic ray exposure (CRE) ages provide information about the parent bodies and source regions of meteorite classes. Cosmogenic noble gases are often used to quantify exposure time scales ranging from tens of ka to hundreds of Ma. The production rate of cosmogenic noble gases is primarily controlled by a meteorite's chemical composition ...
M. Mijjum +5 more
wiley +1 more source

A primitive asteroid that lived fast and died young sampled by a xenolith in the Cold Bokkeveld CM2 carbonaceous chondrite

Meteoritics &Planetary Science, Volume 60, Issue 3, Page 464-483, March 2025.
Abstract Xenoliths in carbonaceous chondrites include lithologies that are unrepresented in the meteorite record and so are a rich source of information on asteroid diversity. Cold Bokkeveld is a CM2 regolith breccia that contains both hydrous and anhydrous lithic clasts. Here, we describe a hydrous clast with a fine‐grained rim.
Martin R. Lee +3 more
wiley +1 more source

Solar and Stellar Dynamos [PDF]

, 2013
1 Magnetohydrodynamics.- 2 Decay and Amplification of Magnetic Fields.- 3 Dynamo Models of the Solar Cycle.- 4 Fluctuations, Intermittency and Predictivity.- 5 Stellar Dynamos.- A Useful Identities and Theorems from Vector Calculus.- B Coordinate Systems and the Fluid Equations.- C Physical and Astronomical Constants.- D Maxwell's Equations and ...
openaire +2 more sources

Iron and copper sulfides in asteroid (162173) Ryugu: Formation conditions and a comparison to the CI and CY chondrites

Meteoritics &Planetary Science, Volume 60, Issue 3, Page 506-528, March 2025.
Abstract JAXA's Hayabusa2 sample return mission visited the volatile‐rich carbonaceous (C‐type) asteroid (162173) Ryugu with the aim of ground‐truthing remote observations, returning a pristine sample from a C‐type asteroid, and strengthening links between asteroids and the meteorite collection. Here, we have conducted a systematic study of coarse (>10
C. S. Harrison +26 more
wiley +1 more source

Dynamics of the solar tachocline [PDF]

, 2003
Douglas Gough & Michael McIntyre proposed, in 1998, the first global and self-consistent model of the solar tachocline. Their model is however far more complex than analytical methods can deal with. In order to validate their work and show how well it can indeed represent the tachocline dynamics, I report on progress in the construction of a fully ...
openaire +2 more sources

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