ASTRONOMY & ASTROPHYSICS, vol.354, no.1, pp.188-192, 2000 (SCI-Expanded)
The new UBV light curves and times of minimum light for V505 Sgr are presented. The B and V band light curves were analyzed by the Wilson-Devinney code and the contribution of the third star to the total light of the triple system was found to be 2.62% for the B and 3.56% for V band. The colour and absolute visual magnitude of the third star were estimated to be 0(m) .46 and 4(m) .00, respectively The apparent visual magnitude of the third star seems fainter by about 3(m) .6 than the eclipsing pair. Only photoelectric times of minimum light were used to determine the parameters for the light-time orbit. The semi-major axis of the third star's orbit around the eclipsing pair was found to be 18.8 AU. The third body completes a revolution on this orbit in 38.13 yr. The semi-amplitude of the radial velocity of the eclipsing pair's mass center was estimated to be 2.37 km s(-1) while 6.4 km s(-1) was found for the third star which agrees with the spectroscopic measurements.