9 papers · 1 filter
The pulsation modes of the pre-white dwarf PG 1159-035
J. E. S. Costa, S. O. Kepler, D. E. Winget +74
PG 1159-035, a pre-white dwarf with T_eff=140,000 K, is the prototype of both two classes: the PG1159 spectroscopic class and the DOV pulsating class. Previous studies of PG 1159-0…
Light curve analysis of the hybrid sdB pulsators HS0702+6043 and HS2201+2610
R. Lutz, S. Schuh, R. Silvotti +6
We present the detection of low-amplitude, long-period g-modes in two individual sdBV stars which are known to be p-mode pulsators. Only few of these hybrid objects, showing both p…
The O-C diagram of the subdwarf B pulsating star HS2201+2610: detection of a giant planet?
R. Silvotti, S. Schuh, R. Janulis +9
In this article we present the O-C diagram of the hot subdwarf B pulsating star HS2201+2610 after seven years of observations. A secular increase of the main pulsation period, Pdot…
Two new ZZ Ceti pulsators from the HS and HE surveys
R. Silvotti, B. Voss, I. Bruni +4
We report the detection of nonradial g-mode oscillations in the DA white dwarfs HS1039+4112 (B=15.9) and HE1429-0343 (B=15.8) from time-series photometry made at the Loiano 1.5 m t…
BeppoSAX observations of AM Herculis in intermediate and high states
G. Matt, D. de Martino, B. T. Gaensicke +5
Temporal and spectral analyses from BeppoSAX observations of AM Her performed during both an intermediate and a high state are presented and discussed. Optical observations taken a…
Time-resolved HST and IUE UV spectroscopy of the Intermediate Polar FO Aqr
D. de Martino, R. Silvotti, D. A. H Buckley +4
Time resolved spectroscopy of the Intermediate Polar FO Aqr reveals the presence of multiple periodicities in the UV range. A strong orbital modulation dominates both continuum and…