Results 61 to 70 of about 1,795 (299)

Quasi-Periodic Pulsations in an M-Class Solar Flare

open access: yes, 2023
We have studied the quasi-periodic pulsations (QPPs) of the M2.3 flare that occurred in the active region NOAA 12172 on 23 September 2014. Through the fast Fourier transform (FFT) method, we decompose the flare light curves into fast- and slowly-varying ...
Jun Xu   +3 more
core   +1 more source

First Detection of Radio Emission Associated with a Classical Cepheid

open access: yesThe Astronomical Journal, 2023
We report the detection of 15 GHz radio continuum emission associated with the classical Cepheid variable star δ Cephei ( δ Cep) based on observations with the Karl G. Jansky Very Large Array.
L. D. Matthews, N. R. Evans, M. P. Rupen
doaj   +1 more source

Polarization‐resolved femtosecond Vis/IR spectroscopy tailored for resolving weak signals in biological samples using minimal sample volume

open access: yesFEBS Open Bio, EarlyView.
Unique biological samples, such as site‐specific mutant proteins, are available only in limited quantities. Here, we present a polarization‐resolved transient infrared spectroscopy setup with referencing to improve signal‐to‐noise tailored towards tracing small signals. We provide an overview of characterizing the excitation conditions for polarization‐
Clark Zahn, Karsten Heyne
wiley   +1 more source

Quasi-periodic pulsations in solar and stellar flares [PDF]

open access: yes, 2016
Light curves of thermal and non-thermal emission associated with solar flares usually contain statistically significant quasi-periodic pulsations (QPP). Typical periods range from a fraction of a second to several tens of minutes.
Nakariakov, Valery M.   +2 more
core   +1 more source

Seismological insights into solar and stellar magnetic activity cycles

open access: yesEPJ Web of Conferences, 2017
The Sun’s magnetic activity cycle varies primarily on a time scale of approximately 11yrs from minimum to maximum and back again. It is well-known that the properties of the Sun’s acoustic oscillations are affected by the near-surface internal magnetic ...
Broomhall Anne-Marie
doaj   +1 more source

Asteroseismology: Looking for Axions in the Red Supergiant Star Alpha Ori

open access: yesThe Astrophysical Journal, 2023
In this work, for the first time, we use seismic data as well as surface abundances to model the supergiant α -Ori, with the goal of setting an upper bound on the axion–photon coupling constant g _a _γ . We find that, in general, stellar models with g _a
Clara Severino, Ilídio Lopes
doaj   +1 more source

Nuclear pore links Fob1‐dependent rDNA damage relocation to lifespan control

open access: yesFEBS Open Bio, EarlyView.
Damaged rDNA accumulates at a specific perinuclear interface that couples nucleolar escape with nuclear envelope association. Nuclear pores at this site help inhibit Fob1‐induced rDNA instability. This spatial organization of damage handling supports a functional link between nuclear architecture, rDNA stability, and replicative lifespan in yeast.
Yamato Okada   +5 more
wiley   +1 more source

A light‐triggered Time‐Resolved X‐ray Solution Scattering (TR‐XSS) workflow with application to protein conformational dynamics

open access: yesFEBS Open Bio, EarlyView.
Time‐resolved X‐ray solution scattering captures how proteins change shape in real time under near‐native conditions. This article presents a practical workflow for light‐triggered TR‐XSS experiments, from data collection to structural refinement. Using a calcium‐transporting membrane protein as an example, the approach can be broadly applied to study ...
Fatemeh Sabzian‐Molaei   +3 more
wiley   +1 more source

Constraints on Stellar Evolution from Pulsations [PDF]

open access: yesSymposium - International Astronomical Union, 1984
Consideration of the many types of intrinsic variable stars, that is, those that pulsate, reveals that perhaps a dozen classes can indicate some constraints that affect the results of stellar evolution calculations, or some interpretations of observations. Many of these constraints are not very strong or may not even be well defined yet. In this review
openaire   +2 more sources

On the Hydrodynamics of Stellar Pulsation and Stability [PDF]

open access: yesInternational Astronomical Union Colloquium, 2002
AbstractMuch of our knowledge of the hydrodynamics of stellar oscillations is summarized in the now-classical article by Ledoux & Walraven in volume 51 of the Handbuch der Physik. It is from that article that I, and many others, first learned the subject.
D.O. Gough, Paul Ledoux
openaire   +1 more source

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