Pulsar
PSR B0820+02 (J0823+0159)
Radio pulsar · binary system
A neutron star spinning once every 0.865 seconds; the beams from its magnetic poles sweep across Earth on every turn. It shares a 1,232 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 | Hydra |
| Period | 864.9 ms |
| Period derivative | 1.0×10⁻¹⁶ s/s |
| Characteristic age | 131 million years |
| Magnetic field | 3.0×10¹¹ G |
| Spin-down luminosity | 6.4×10³⁰ erg/s |
| Dispersion measure | 23.7 pc/cm³ |
| Distance | 2,700 pc (8.8 thousand ly) |
| Companion | helium white dwarf (estimated), ~0.23 M☉ |
| Orbital period | 1,232 days |
| Eccentricity | 0.0119 |
| Discovery | 1978 · mol2, ar327, gb3, gb4, lotaas, pkshl |
| Source | ATNF Pulsar Catalogue |
| Right ascension (J2000) | 8h 23m 09.8s |
| Declination (J2000) | +1° 59′ 12″ |
In the sky
Visible from the whole Northern Hemisphere and south to latitude 88° S. It stands highest at midnight in January, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out 8,806 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 156 million years.