Pulsar
PSR J1643-1224
Millisecond pulsar · binary system
A millisecond pulsar spinning 216 times per second: an old neutron star spun up again (“recycled”) by matter transferred from a companion. It shares a 147 days orbit with a helium white dwarf. Period, spin-down, distance and orbit come from the ATNF Pulsar Catalogue; the beam geometry is illustrative.
| Type | Pulsar |
|---|---|
| Constellation | Ophiuchus |
| Period | 4.622 ms (216 Hz) |
| Period derivative | 1.8×10⁻²⁰ s/s |
| Characteristic age | 4.0 billion years |
| Magnetic field | 3.0×10⁸ G |
| Spin-down luminosity | 7.4×10³³ erg/s |
| Dispersion measure | 62.4 pc/cm³ |
| Distance | 740 pc (2.4 thousand ly) |
| Companion | helium white dwarf (estimated), ~0.14 M☉ |
| Orbital period | 147 days |
| Eccentricity | 0.000506 |
| Discovery | 1995 · pks70, pkssw |
| Source | ATNF Pulsar Catalogue |
| Right ascension (J2000) | 16h 43m 38.2s |
| Declination (J2000) | −12° 24′ 59″ |
In the sky
Visible from the whole Southern Hemisphere and north to latitude 78° N. South of latitude 78° S it never sets. It stands highest at midnight in May, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out around 389 BC. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 43 million years.