PSR J0437−4715
PSR J0437−4715 is a pulsar. Discovered in the Parkes 70 cm survey, it remains the closest and brightest millisecond pulsar (MSP) known. The pulsar rotates about its axis 173.7 times per second and therefore completes a rotation every 5.75 milliseconds. It emits a searchlight-like radio beam that sweeps past the Earth each time it rotates. Currently the most precisely located object outside of the Solar System, PSR J0437-4715 is 156.3 parsecs or 509.8 light-years distant.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Pictor |
| Right ascension | 04h 37m 15.81476s |
| Declination | −47° 15′ 08.6242″ |
| Apparent magnitude (V) | 20.98±0.09 |
| Characteristics | |
| Spectral type | Pulsar |
| Astrometry | |
| Proper motion (μ) | RA: 121.453 mas/yr Dec.: 71.457 mas/yr |
| Distance | 509.8 ly (156.3 pc) |
| Details | |
| Mass | 1.44 M☉ |
| Other designations | |
PSR B0435−47, 1RXS J043714.5−471503 | |
| Database references | |
| SIMBAD | data |
This pulsar is distinguished by being the most stable natural clock known and is debatably more stable than man-made atomic clocks. Its stability is about one part in 1015. Two other pulsars, PSR B1855+09 and PSR B1937+21 are known to be comparable in stability to atomic clocks, or about 3 parts in 1014.
PSR J0437−4715 is the first MSP to have its X-ray emission detected and studied in detail. It is also the first of only two pulsars to have the full three-dimensional orientation of its orbit determined.
Optical observations indicate that the binary companion of PSR J0437-4715 is most likely a low-mass helium white dwarf. The pulsar is about 1.4 solar mass (M☉) and the companion is about 0.25 M☉. The pair revolve around each other every 5.75 days in nearly perfect circular orbits.