Discovery of a 6.1-ms binary pulsar PSR1953 + 29

Abstract

A systematic search for fast radio pulsars in some of the error boxes of the γ-ray satellite COS B¹ unidentified point sources^2–4 on the 305-m Arecibo Observatory radiotelescope was started 3 years ago. The motivation for the search and the method and limitations are given elsewhere⁵. One of the search areas covered was the γ-source 2CG065+00. We report here the discovery of a 6.13317-ms pulsar in a binary system with a 120-day orbital period inside the error box of this source. The initial search observation (23 July 1980) with a sampling rate of 4.167 ms produced an aliased (76.93 Hz) detection at 430 MHz. Confirmatory observations made in March 1983, showed a variable pulse frequency indicating a Doppler shift due to a periodic orbit around another object⁶. A compilation of measured system parameters and the underlying assumptions are given in Table 1.