Search results for "Stellar physics"

showing 4 items of 4 documents

A stellar flare-coronal mass ejection event revealed by X-ray plasma motions

2019

Coronal mass ejections (CMEs), often associated with flares, are the most powerful magnetic phenomena occurring on the Sun. Stars show magnetic activity levels up to 10^4 times higher, and CME effects on stellar physics and circumstellar environments are predicted to be significant. However, stellar CMEs remain observationally unexplored. Using time-resolved high-resolution X-ray spectroscopy of a stellar flare on the active star HR 9024 observed with Chandra/HETGS, we distinctly detected Doppler shifts in S XVI, Si XIV, and Mg XII lines that indicate upward and downward motions of hot plasmas (~10-25 MK) within the flaring loop, with velocity v~100-400 km/s, in agreement with a model of fl…

Angular momentumX-ray Astronomy010504 meteorology & atmospheric sciencesAstrophysics::High Energy Astrophysical PhenomenaStars: flareFOS: Physical sciencesAstrophysicsKinetic energy01 natural scienceslaw.inventionSpitzer Space Telescopelaw0103 physical sciencesCoronal mass ejectionAstrophysics::Solar and Stellar AstrophysicsStars: coronae010303 astronomy & astrophysicsSolar and Stellar Astrophysics (astro-ph.SR)0105 earth and related environmental sciencesLine (formation)PhysicsHigh Energy Astrophysical Phenomena (astro-ph.HE)Astronomy and AstrophysicsStarsAstrophysics - Solar and Stellar AstrophysicsStellar physicsPhysics::Space PhysicsStars: CMEAstrophysics::Earth and Planetary AstrophysicsAstrophysics - High Energy Astrophysical PhenomenaFlare
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Stellar physics with the ALHAMBRA photometric system

2011

GREAT-ESF Workshop: Stellar Atmospheres in the Gaia Era 23–24 June 2011, Vrije Universiteit Brussels, Belgium.

PhysicsHistoryEstimation theoryExtinction (astronomy)AstronomyPhotometric systemAstrophysicsStellar classificationComputer Science ApplicationsEducationStarsPhotometry (astronomy)Stellar physicsRange (statistics)
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Solar Neutrino Spectroscopy

2017

More than forty years after the first detection of neutrinos from the Sun, the spectroscopy of solar neutrinos has proven to be an on-going success story. The long-standing puzzle about the observed solar neutrino deficit has been resolved by the discovery of neutrino flavor oscillations. Today's experiments have been able to solidify the standard MSW-LMA oscillation scenario by performing precise measurements over the whole energy range of the solar neutrino spectrum. This article reviews the enabling experimental technologies: On the one hand mutli-kiloton-scale water Cherenkov detectors performing measurements in the high-energy regime of the spectrum, on the other end ultrapure liquid-s…

PhysicsStandard solar modelParticle physicsPhysics - Instrumentation and Detectors010308 nuclear & particles physicsPhysics::Instrumentation and DetectorsSolar neutrinoPhysics beyond the Standard ModelHigh Energy Physics::PhenomenologyGeneral Physics and AstronomyFOS: Physical sciencesContext (language use)Instrumentation and Detectors (physics.ins-det)01 natural sciencesHigh Energy Physics - ExperimentHigh Energy Physics - Experiment (hep-ex)Stellar physics0103 physical sciencesHigh Energy Physics::ExperimentNeutrinoNuclear Experiment (nucl-ex)010306 general physicsNeutrino oscillationNuclear ExperimentCherenkov radiation
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The Gaia-ESO Survey: Catalogue of Hα emission stars

2015

We discuss the properties of Hα emission stars across the sample of 22035 spectra from the Gaia-ESO Survey internal data release, observed with the GIRAFFE instrument and largely belonging to stars in young open clusters. Automated fits using two independent Gaussian profiles and a third component that accounts for the nebular emission allow us to discern distinct morphological types of Hα line profiles with the introduction of a simplified classification scheme. All in all, we find 3765 stars with intrinsic emission and sort their spectra into eight distinct morphological categories: single-component emission, emission blend, sharp emission peaks, double emission, P-Cygni, inverted P-Cygni…

PhysicscatalogStars: emission-line BeStar formationAstrophysics::High Energy Astrophysical PhenomenaSIMBADstars: peculiarAstronomy and AstrophysicsAstrophysics::Cosmology and Extragalactic AstrophysicsAstrophysicsopen clusters and associations: generalAstronomy and AstrophysicSpectral lineStarsline: profile13. Climate actionSpace and Planetary ScienceStellar physicsstars: activityAstrophysics::Solar and Stellar AstrophysicsEmission spectrumAstrophysics::Galaxy AstrophysicsOpen clusterLine (formation)
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