Open AccessIrradiation of the secondary star in X‐ray Nova Scorpii 1994 (=GRO J1655–40)
Author(s) -
Shahbaz T.,
Groot P.,
Phillips S. N.,
Casares J.,
Charles P. A.,
Van Paradijs J.
Publication year - 2000
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2000.03341.x
Subject(s) - physics , astrophysics , star (game theory) , amplitude , radial velocity , irradiation , light curve , nova (rocket) , astronomy , stars , optics , nuclear physics , aeronautics , engineering
We have obtained intermediate resolution optical spectra of the black‐hole candidate Nova Sco 1994 in 1996 June, when the source was in an X‐ray/optical active state ( R ∼15.05). We measure the radial velocity curve of the secondary star and obtain a semi‐amplitude of 279±10 km s −1 ; a value which is 30 per cent larger than the value obtained when the source is in quiescence. Our large value for K 2 is consistent with per cent of the secondary star’s surface being heated, compared with 35 per cent, which is what one would expect if only the inner face of the secondary star were irradiated. Effects such as irradiation‐induced flows on the secondary star may be important in explaining the observed large value for K 2 .