We present orbital parameters of the 3.6 ms binary pulsar 1908+00 in the globular cluster NGC 6760. The orbital period is 3.4 hr, and the mass function is 3 × 10-6 M⊙, implying a minimum companion mass of 0.018 M⊙. The companion is probably degenerate; and if it is hydrogen, it is close to overflowing its Roche lobe. The only other millisecond binary radio pulsar systems with orbital period <10 hr and mass function below 10-3 M⊙ are the eclipsing pulsars 1957+20 and 1744-24A, and the very low mass binary 0021-72J. These pulsars are ablating their companions and may be the progenitors of isolated millisecond pulsars. PSR 1908+00 shows no evidence for long-duration eclipses as are seen in 1744-24A, but short-duration eclipses as in 1957+20 are not excluded.
All Science Journal Classification (ASJC) codes
- Astronomy and Astrophysics
- Space and Planetary Science