Multi-wavelength photometric studies of SS 433 (also known as V1343 Aquilae) were carried
out during the month of May, 2013 using the 104-cm Sampurnanand Optical Telescope at ARIES,
Nainital, and their results are presented. The study aims to examine the periodicity in the obtained
light curve for the object and correlate the results with previous studies. The present models for the
system indicate that it is an eclipsing binary system with a B or A type supergiant and a compact
object (possibly a low mass black hole) undergoing supercritical accretion from its companion star.
Using data from the present photometric observations, the temperature of the secondary star
appears to be around 9,000K - 11,000K, which is in agreement with typical temperatures for late
B or early A type stars. Further, the radius estimated using typical luminosity values for B and A
type supergiants is close to the expected radius for these stars. Using velocity data from previous
spectroscopic studies and assuming an approximately circular orbit for the system, the binary
separation turns out to be about 0.3 AU, with individual masses of 3.9 Msun for the compact object
and 12.7 Msun for the companion star. Using Eggleton’s approximation for the radius of Roche
Lobe for an object in a binary system, the secondary star appears to have filled its Roche Lobe
completely.
Further, using temperature extracted for the star surface, it is estimated that the radius of the
accretion disk is likely to be equal to the equatorial radius of the Roche Lobe for the compact
object. The circularization radius for the incoming stream of material is estimated to be around
5.7 Rsun.