2019A&A...626A..94G


C.D.S. - SIMBAD4 rel 1.7 - 2020.07.14CEST19:28:55

2019A&A...626A..94G - Astronomy and Astrophysics, volume 626A, 94-94 (2019/6-1)

HD 96446: a long-period binary with a strongly magnetic He-rich primary with β Cephei pulsations.

GONZALEZ J.F., BRIQUET M., PRZYBILLA N., NIEVA M.-F., DE CAT P., SAESEN S., HUBRIG S., THOUL A., PAPICS P.I., PALAVERSA L., NAEF D., NEVEU-VAN MALLE M., JARVINEN S., POLLARD K.R., KILMARTIN P., MOWLAVI N. and BUTLER K.

Abstract (from CDS):


Aims. HD 96446 is a magnetic B2p He-strong star that has been reported to be a β Cep pulsator. We present a detailed spectroscopic analysis of this object based on an intensive observational data set obtained in a multisite campaign with the spectrographs CORALIE, FEROS, and HARPS (La Silla); UVES (Paranal); HERCULES (Mt. John Observatory); and GIRAFFE (SAAO).
Methods. Radial velocities were measured by cross-correlations and analysed to detect periodic variations. On the other hand, the mean spectrum was fit with spectral synthesis to derive atmospheric parameters and chemical abundances.
Results. From the analysis of radial velocities, HD 96446 was found to be a spectroscopic binary with a period of 799 days. The stellar companion, which contributes only ∼5% of the total flux, is an A0-type star. A frequency analysis of the radial velocities allowed us to detect two pulsational modes with periods 2.23 h and 2.66 h. The main mode is most probably a low-inclination, dipole mode (l, m)=(1, 0), and the second pulsation mode corresponds to (l, m)=(2, 2) or to a pole-on (l, m)=(3, 2) configuration. In addition to radial velocities, the main pulsation mode is evidenced through small variations in the spectral morphology (temperature variations) and the light flux. The rotation period of 23.4d, was detected through the variation in line intensities. Chemical abundances are unevenly distributed over the stellar surface, with helium concentrated at the negative magnetic pole and most metals strengthened at lower latitudes. The mean chemical abundance of helium is strongly abnormal, reaching a value of 0.60 (number fraction).

Abstract Copyright: © ESO 2019

Journal keyword(s): binaries: spectroscopic - stars: chemically peculiar - stars: early-type - stars: magnetic field - stars: oscillations - stars: individual: HD 96446

VizieR on-line data: <Available at CDS (J/A+A/626/A94): table3.dat>

Simbad objects: 4

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Number of rows : 4

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2020
#notes
1 HD 43317 Pu* 06 15 47.0136233779 +04 17 01.097508973 5.82 6.456 6.614     B3IV 90 0
2 HD 96446 Pu* 11 06 05.8217576741 -59 56 59.536118851 5.81 6.57 6.69     B2IIIp 149 0
3 V* V2052 Oph bC* 17 56 18.3998830562 +00 40 13.276647618 5.28 5.874 5.820     B3III 197 0
4 EM* LkHA 123 Em* 18 02 23.13015 -23 01 59.9462   8.72 6.80 9.37   B6V 36 0

    Equat.    Gal    SGal    Ecl

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2020.07.14-19:28:55

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