Abstract:
Photoelectric observations of the Algol-type eclipsing binary R Canis Majoris during three consequtive observing seasons of 1979-82 gave a total of ten primary minima in each of the V and B passbands and nine in the U passband. The (O - C) curve obtained by using these minima and those available in the literature indicates that the period changes noticed in R CMa are due to light-time effect. The elements of the light-time orbit are determined. The mass of the third body is derived to be ~~ 0.5 M for i values ranging from 60/supo/ to 90/supo/. The low mass and the absence of significant light contribution suggests that the third body may me an M dwarf or a white dwarf.
