Pulsar
PSR J2302+4442
Millisecond pulsar · binary system
A millisecond pulsar spinning 193 times per second: an old neutron star spun up again (“recycled”) by matter transferred from a companion. It shares a 126 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 | 5.192 ms (193 Hz) |
| Period derivative | 1.4×10⁻²⁰ s/s |
| Characteristic age | 5.9 billion years |
| Magnetic field | 2.7×10⁸ G |
| Spin-down luminosity | 3.9×10³³ erg/s |
| Dispersion measure | 13.7 pc/cm³ |
| Distance | 859 pc (2.8 thousand ly) |
| Companion | helium white dwarf (estimated), ~0.34 M☉ |
| Orbital period | 126 days |
| Eccentricity | 0.000503 |
| Discovery | 2011 · misc, FermiBlind, gbncc |
| Source | ATNF Pulsar Catalogue |
| Right ascension (J2000) | 23h 02m 47.0s |
| Declination (J2000) | +44° 42′ 22″ |
In the sky
Visible from the whole Northern Hemisphere and south to latitude 45° S. North of latitude 45° N it never sets. It stands highest at midnight in September, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out around 777 BC. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 50 million years.