Bibcode
van der Hooft, F.; Groot, P. J.; Shahbaz, T.; Augusteijn, T.; Casares, J.; Dieters, S.; Greenhill, J.; Hill, K.; Scheers, L. H. A.; Naber, R. M.; de Jong, J. A.; Charles, P. A.; van Paradijs, J.
Referencia bibliográfica
Monthly Notices of the Royal Astronomical Society, Volume 286, Issue 4, pp. L43-L49.
Fecha de publicación:
4
1997
Número de citas
21
Número de citas referidas
16
Descripción
We have measured the brightness of the optical counterpart of the black
hole X-ray binary Nova Sco 1994 (GRO J1655-40) during 40 nights between
1995 May 3 and July 27. From our observations and data from the
literature we refine the orbital period to be 2.620 40+/-0.000 98 d. We
model the R-band light curve as primarily arising from an X-ray heated
secondary, using a model that includes a Roche lobe filling secondary
star, the effects of X-ray heating on both the concave accretion disc
and the X-ray illuminated surface of the secondary, shadowing of the
secondary and disc, and mutual eclipses of the disc and the secondary
star. From the shape of the light curve we constrain the inclination of
the system to lie in the range 65 deg-76 deg and constrain the mass
ratio q=M_1/M_2 to lie in the range 3.8-5.5. This implies a mass range
for the secondary star and compact object of 0.95-1.8 Msolar and 4.9-6.8
Msolar, respectively. The (V-R) and (R-i) colour curves do not show
evidence of significant variability with orbital phase during 1995
June-July, their average values being 1.06(3) and 0.86(2) mag,
respectively.