0000000000530461

AUTHOR

J. Kastner

showing 3 related works from this author

A rapid H? change in X Persei

1993

A trend of decreasing Hα emission over a period of thirty minutes is apparent in a series of spectra of X Persei taken on 31 December, 1987. This change appears to be astrophysical in origin and it indicates an anomalous state for X Persei that may be linked to its transition from a Be star to a normal B star, which occurred sometime between March 1988 and November 1990.

PhysicsX-ray astronomySpace and Planetary ScienceBe starStellar rotationAstronomyAstronomy and AstrophysicsH-alphaAstrophysicsEmission spectrumVariable starEquivalent widthMain sequenceAstrophysics and Space Science
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A phase change in X Persei

1991

We present a series of optical spectroscopic and infrared photometric observations of the Be/X-ray binary system X Per made over the last four years. Over this period the Hα line profile changed from emission to absorption, accompanied by a decrease in the infrared flux by over a magnitude and a flattening of the infrared spectrum. Such behaviour is consistent with the loss of the circumstellar disc or shell of material around the Be star and the reversion to a normal O/B-type star.

PhysicsAbsorption spectroscopyInfraredBe starAstrophysics::High Energy Astrophysical PhenomenaX-ray binaryAstronomyBalmer seriesAstronomy and AstrophysicsAstrophysics::Cosmology and Extragalactic AstrophysicsAstrophysicssymbols.namesakeApparent magnitudeSpace and Planetary SciencesymbolsAstrophysics::Solar and Stellar AstrophysicsH-alphaAstrophysics::Earth and Planetary AstrophysicsEmission spectrumAstrophysics::Galaxy AstrophysicsMonthly Notices of the Royal Astronomical Society
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The close classical T Tauri binary V4046 Sgr: Complex magnetic fields & distributed mass accretion

2011

We report here the first results of a multi-wavelength campaign focussing on magnetospheric accretion processes within the close binary system V4046 Sgr, hosting two partly-convective classical T Tauri stars of masses ~0.9 Msun and age ~12 Myr. In this paper, we present time-resolved spectropolarimetric observations collected in 2009 September with ESPaDOnS at the Canada-France-Hawaii Telescope (CFHT) and covering a full span of 7d or ~2.5 orbital/rotational cycles of V4046 Sgr. Small circularly polarised Zeeman signatures are detected in the photospheric absorption lines but not in the accretion-powered emission lines of V4046 Sgr, thereby demonstrating that both system components host lar…

stars: formation[SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph]stars: individual: V4046 SgrAstrophysics::High Energy Astrophysical PhenomenaFOS: Physical sciencesAstrophysics::Cosmology and Extragalactic Astrophysicsstars: imagingtechniques: polarimetricSettore FIS/05 - Astronomia E AstrofisicaAstrophysics - Solar and Stellar Astrophysicsstars: rotation[SDU]Sciences of the Universe [physics]stars: magnetic fieldsAstrophysics::Solar and Stellar Astrophysicstechniques: polarimetric stars: formation stars: imaging stars: individual: V4046 Sgr stars: magnetic fields stars: rotationAstrophysics::Earth and Planetary AstrophysicsSolar and Stellar Astrophysics (astro-ph.SR)Astrophysics::Galaxy Astrophysics
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