1994A&A...291..910P


Query : 1994A&A...291..910P

1994A&A...291..910P - Astronomy and Astrophysics, volume 291910-918 (1994/11-3)

Spectrum variability of ET Andromedae: Si and He surface mapping.

PISKUNOV N., RYABCHIKOVA T.A., KUSCHNIG R. and WEISS W.W.

Abstract (from CDS):

ETAnd is a silicon star with a rotation period of 1.62d and the visible component of a binary system with an orbital period of 48.3d. We present abundance maps for silicon and helium, based on OHP-AURELIE spectra, and demonstrate that silicon and helium are concentrated in a belt-like structure along the magnetic equator. Surface regions with a silicon overabundance are correlated with helium underabundance. In the framework of diffusion theory, this pattern implies that a magnetic field configuration of ETAnd which favours the elevation of Si, simultaneously causes He to sink. In addition, we comment on the significance of Doppler mapping of CP stars for a correct abundance determination and on implications to pulsation mode identifications. We discuss our upper limit for short time-scale radial velocity variations of 1.4km/s, which contrasts to 4km/s, as was claimed in the literature with a period of 4.8h.

Abstract Copyright: ∼

Journal keyword(s): stars: chemically peculiar - stars: activity - stars: individual: ET And - stars: imaging

Simbad objects: 7

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Number of rows : 7
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2026
#notes
1 * gam02 Ari PM* 01 53 31.8129284424 +19 17 37.879979172   4.49 4.52     A2IVpSiSrCr 162 0
2 * 56 Ari a2* 03 12 14.2461137352 +27 15 25.085668788 5.22 5.64 5.76     B6IV-V 271 0
3 * 11 Ori a2* 05 04 34.1491891634 +15 24 14.767720310   4.609 4.661     A1VpSiCr 156 0
4 * tet Aur a2* 05 59 43.27012 +37 12 45.3047 2.36 2.54 2.62 2.62 2.68 A0VpSi 296 1
5 V* CU Vir a2* 14 12 15.8055434051 +02 24 33.945178515 4.46 4.90 5.02 5.10 5.23 ApSi 411 0
6 V* BP Boo a2* 15 42 50.7602109000 +52 21 39.243860316   5.430 5.482     A0VpSiCr 140 0
7 V* ET And a2* 23 17 56.0115388728 +45 29 20.119357248   6.447 6.479     A0VpSiSr 151 0

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