Period Measurements of the 50 Millisecond Pulsar PSR 0540-69 with the EXOSAT Satellite
Abstract
The period of the 50 ms pulsar PSR 0540 - 69 in the Large Magellanic Cloud was determined using five separate X-ray observations with the Exosat satellite in the interval August 12, 1984 to June 30, 1985. Together with Einstein observations and contemporaneous optical data, the Exosat periods can be fitted well to a quadratic curve yielding a braking index of 2.74 + or - 0.10. This behavior is not compatible with the optical and X-ray observations commencing about a year after Exosat, indicating the PSR 0540 - 69 is susceptible to discontinuous changes in its spin-down behavior.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- April 1990
- DOI:
- 10.1086/185698
- Bibcode:
- 1990ApJ...353L..21O
- Keywords:
-
- Exosat Satellite;
- Magellanic Clouds;
- Pulsars;
- X Ray Sources;
- Astronomical Photometry;
- Crab Nebula;
- Astrophysics;
- PULSARS;
- STARS: NEUTRON;
- X-RAYS: SPECTRA