Results 121 to 130 of about 1,795 (299)
Pulsational Instability of Quasi-stars: Interpreting the Variability of Little Red Dots
The Astrophysical Journal LettersThe JWST discovery of “little red dots” (LRDs) has revealed a population of compact, red sources at z ∼ 5–10 that likely host supermassive black holes.
Matteo Cantiello +7 more
doaj +1 more source
Time‐Dependent Oxidation and Scale Evolution of a Wrought Co/Ni‐Based Superalloy
Advanced Engineering Materials, EarlyView.This study shows how a new wrought Co/Ni‐based superalloy resists oxidation at 800 ∘$^\circ$C. The oxide scale changes from rough, fast‐growing spinel to a dense, protective chromia–alumina layer. Atom probe analysis reveals tiny refractory‐rich bubbles at the interface that mark the transition to long‐term, diffusion‐controlled protection ...
Cameron Crabb +6 more
wiley +1 more source
Theoretical Description and Basic Physics of Stellar Pulsations
As an introduction to the subject basic properties of stellar pulsations are derived using simple intuitive estimates. With respect to a theoretical description of pulsating stars the physical principles governing stellar structure and dynamics are ...
Glatzel, Wolfgang
core
, 2007 . We review some of the recent advances in nonlinear pulsation theory, but also insist on some of the major extant shortcomings. 1. Introduction It is a great pleasure for me to dedicate this lecture to Art Cox whose contributions to nonlinear ...
J. R. Buchler
core
KIC 6362386: An Eclipsing Binary with γ Doradus–type Pulsations and Starspots
The Astronomical JournalKIC 6362386 is an eclipsing binary system that exhibits both γ Doradus ( γ Dor)–type pulsations and starspots. In this study, we investigated this binary system using the Kepler photometry and the spectroscopic data from the Large Sky Area Multi-Object ...
Mengqi Jin +7 more
doaj +1 more source
Advanced Engineering Materials, EarlyView.The temperature dependence of fatigue behavior in nickel‐based superalloys is investigated through high‐resolution measurements of plastic localization. While increasing temperature reduces localization and enhances fatigue performance in René 88DT, Inconel 718 exhibits a sharp degradation at intermediate temperature due to intensified slip ...
M. Calvat +5 more
wiley +1 more source
Space-based photometry reveals regular high-frequency patterns in many young Scuti stars. These pulsations provide a powerful means of inferring stellar properties, particularly ages, for young Scuti stars for which traditional age-dating methods are ...
Murphy, Simon J. +2 more
core +1 more source
The Probable Direct-imaging Detection of the Stellar Companion to Betelgeuse
The Astrophysical Journal LettersBetelgeuse—the closest M-supergiant to the Sun—has recently been predicted to host a lower-mass stellar companion that orbits the primary with a period of ∼6 yr.
Steve B. Howell +5 more
doaj +1 more source
Fatigue Crack Initiation and Growth in Nanocrystalline Ni at Multiple Length‐Scales
Advanced Engineering Materials, EarlyView.Overview of miniaturized in situ SEM fatigue setup and resultant fatigue crack growth data for nanocrystalline Ni. The presented study focuses on the analysis of fatigue crack growth rate (FCGR) in focused ion beam‐notched microcantilevers prepared from nanocrystalline (NC) Ni as a model material.
Igor Moravcik +7 more
wiley +1 more source
The Astrophysical JournalTheoretical investigations predict a minimum mass ratio of about 0.085–0.095 for contact binaries. If the mass ratio is below the critical value, a tidal instability occurs, forcing the stars to merge into a single object.
Xiaobin Zhang +3 more
doaj +1 more source