A. Wolszczan, Arecibo Observatory, reports: "I have discovered two short-period pulsars, PSR 1257+12 and PSR 1534+12, during the high-galactic-latitude (b > 30 deg) survey for millisecond pulsars with the 305-m Arecibo radiotelescope at 430 MHz. The data were analyzed on the Cornell National Supercomputer Facility. The preliminary parameters for PSR 1257+12 are R.A. = 12h57m31s, Decl. = +12 56'10" (equinox 1950.0); period, P, 6.218 ms; dispersion measure 10.1 +/- 0.2 pc cmE-3; flux density at 430 MHz, S about 15 mJy. Preliminary parameters for PSR 1534+12 are R.A. = 15h34m47s, Decl. = +12 05'37"; P = 37.904 ms; dispersion measure 11.6 +/- 0.2 pc cmE-3; S about 8 mJy. The accuracy of the coordinates is limited by the 3' FWHM of the telescope beam at 1400 MHz. The preliminary timing results indicate that PSR 1257+12 is either an isolated pulsar or it may be a member of a long-period binary system. PSR 1534+12, on the other hand, is in a fast binary system with orbital period 10.1 hr, full radial velocity amplitude 400 km/s, and eccentricity 0.27. The mass function of the system, 0.32 solar units, suggests that the pulsar's companion is another compact star. Timing observations to measure accurately the parameters of both pulsars are in progress."
International Astronomical Union Circular
- Pub Date:
- August 1990