SIMBAD references

2003A&A...406.1019N - Astronomy and Astrophysics, volume 406, 1019-1031 (2003/8-2)

Discovery of a magnetic field in the Slowly Pulsating B star zet Cas.

NEINER C., GEERS V.C., HENRICHS H.F., FLOQUET M., FREMAT Y., HUBERT A.-M., PREUSS O. and WIERSEMA K.

Abstract (from CDS):

objS{zet Cas}{ζ Cas} is a B2IV star with vsini=17km/s. Time-resolved circular spectropolarimetric observations of ζ Cas obtained in 2001 and 2002 with the Musicos echelle spectropolarimeter at the 2-m Telescope Bernard Lyot (TBL) show a sinusoidally varying longitudinal magnetic field with a strength between 10G and -46G for the averaged line-of-sight component, corresponding to Bpol=335+120–65G. The period corresponds very accurately with the 5.37045-day period as derived from stellar wind variations observed in the ultraviolet. The epoch of the positive maximum field corresponds in phase with the maximum emission in the UV wind lines. This gives compelling evidence for a magnetic rotator model for this star, with an unambiguous rotation period of 5.37-days. We searched for periodicity in line-profile variations (lpv), radial velocity and minimum intensity curves in the ∼400 optical spectra. We found a non-radial pulsation mode with l=2±1 at the frequency f=0.64c/d. From this periodicity and from stellar parameters derived from model fits, we propose to classify ζ Cas as a Slowly Pulsating B (SPB) star. This is the third detection of a magnetic field in an early B-type pulsating star and the first one in a SPB star.

Abstract Copyright:

Journal keyword(s): stars: magnetic fields - stars: oscillations - stars: winds, outflows

Simbad objects: 3

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2019.09.17-17:33:04

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