Pulsar
PSR J0218+4232
Millisecond pulsar · binary system
A millisecond pulsar spinning 430 times per second: an old neutron star spun up again (“recycled”) by matter transferred from a companion. It shares a 2.029 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 | Andromeda |
| Period | 2.323 ms (430 Hz) |
| Period derivative | 7.7×10⁻²⁰ s/s |
| Characteristic age | 476 million years |
| Magnetic field | 4.3×10⁸ G |
| Spin-down luminosity | 2.4×10³⁵ erg/s |
| Dispersion measure | 61.3 pc/cm³ |
| Distance | 3,150 pc (10.3 thousand ly) |
| Companion | helium white dwarf (estimated), ~0.20 M☉ |
| Orbital period | 2.029 days |
| Eccentricity | 0.000007 |
| Discovery | 1995 · misc, FermiBlind, gbncc |
| Source | ATNF Pulsar Catalogue |
| Right ascension (J2000) | 2h 18m 06.4s |
| Declination (J2000) | +42° 32′ 18″ |
In the sky
Visible from the whole Northern Hemisphere and south to latitude 47° S. North of latitude 47° N it never sets. It stands highest at midnight in October, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out 10 thousand years ago. At that time the first farming villages were being founded; there was no writing yet. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 182 million years.