Pulsar
PSR B1920+21 (J1922+2110)
Radio pulsar
A neutron star spinning once every 1.08 seconds; the beams from its magnetic poles sweep across Earth on every turn. Period, spin-down, distance and orbit come from the ATNF Pulsar Catalogue; the beam geometry is illustrative.
| Type | Pulsar |
|---|---|
| Constellation | Vulpecula |
| Period | 1.078 s |
| Period derivative | 8.2×10⁻¹⁵ s/s |
| Characteristic age | 2.1 million years |
| Magnetic field | 3.0×10¹² G |
| Spin-down luminosity | 2.6×10³² erg/s |
| Dispersion measure | 217.1 pc/cm³ |
| Distance | 4,000 pc (13.0 thousand ly) |
| Discovery | 1973 · jb1, ar1, ar2, ar3, gb1, gb3, lotaas, fast_gpps |
| Source | ATNF Pulsar Catalogue |
| Right ascension (J2000) | 19h 22m 53.5s |
| Declination (J2000) | +21° 10′ 42″ |
In the sky
Visible from the whole Northern Hemisphere and south to latitude 69° S. North of latitude 69° N it never sets. It stands highest at midnight in July, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out 13 thousand years ago. At that time Homo sapiens was spreading out of Africa; there was no farming yet. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 231 million years.