A study of the radial velocity of the star Θ1 Ori C

The radial velocities of the star circle minus(1) Ori C were measured from IUE spectra and are compared with puhlished data. Two companions (C1 and C2) are assumed to be 1)resent. The probable periods for companion C1 can be estimated from the formula P = 729.6/L days, where L < 13 is an integer. Radial-velocity curves were constructed for L = 11 and 12. The orbit turned out to be elliptical. At L = 11, the orbital elements are P = 66.3(1) days, gamma = 10.0(2) km s(-1), K = 6.1(1) km s(-1), omega = -2.88(5) rad, e = 0.43(6), and Ep = JD 24490:14.7(4). The errors in the last decimal digit are given in parentheses. Companion C2 was detected by temporal variations in the gamma velocity of companion CI. Its orbit is assumed to be circular with the following elements: P = 120(6) yr, gamma = 22(1) km s(-1), K = 13('2) km s(-1), and EP = 1911(3) yr. (C) 2002 MAIK Nauka/Interperiodica.