1995BaltA...4..245P

Query : 1995BaltA...4..245P

1995BaltA...4..245P - Baltic Astronomy, 4, 245-260 (1995/October-0)

Whole Earth Telescope observations and seismological analysis of the cool ZZ Ceti star GD 154.

PFEIFFER B., VAUCLAIR G., DOLEZ N., CHEVRETON M., FREMY J.-R., BARSTOW M.A., BELMONTE J.A., KEPLER S.O., KANAAN A., GIOVANNINI O., FONTAINE G., BERGERON P., WESEMAEL F., GRAUER A.D., NATHER R.E., WINGET D.E., PROVENCAL J., CLEMENS J.C., BRADLEY P., DIXSON J.S., KLEINMAN S.J., WATSON T.K., CLAVER C.F., MAZEH T., LEIBOWITZ E.M. and MOSKALIK P.

Abstract (from CDS):

Fast photometric observations of a cool DAV star, GD 154, obtained with the Whole Earth Telescope are presented. GD 154 is one of the coolest pulsating DA white dwarfs and its study is relevant for understanding of the red edge of the ZZ Ceti instability strip. Its power spectrum is dominated by three independent modes (P1=1186.5 s, P2=1088.6 s and P3=402.6 s). It also exhibits harmonics and linear combinations of these three modes. However, none of the half-integer harmonics, reported in previous observations, were present during the WET campaign. Assuming that the observed modes are trapped in the thin outer hydrogen layer, an identification of the pulsation modes is proposed. The rotation period (2.3 days) and the mass of the outer hydrogen layer (2x10–10 M* ) are derived.

Abstract Copyright: ∼

Journal keyword(s): stars: interiors - stars: oscillations - stars: pulsations - stars: structure - stars: individual: GD 154

Simbad objects: 5

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Number of rows : 5
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 EGGR 34 WD* 04 20 17.2470258432 +36 16 27.266860200   15.79   15.5   DA4.4 76 0
2 V* BR Cam WD* 04 59 27.2435598163 +55 25 21.057303220   15.98   16.1   DA4.3 70 0
3 Ton 1559 WD* 13 09 57.6766028952 +35 09 47.187935136   15.51   15.2   DA4.4 138 0
4 V* EM UMa WD* 13 53 09.9687043752 +48 40 21.171407268   16.5   17.0   DB2 105 0
5 Ross 808 WD* 16 01 23.1868739817 +36 48 34.288643534   14.53   14.7   DA4.4 117 0

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