Pulsar
PSR B2217+47 (J2219+4754)
Radio pulsar
A neutron star spinning once every 0.538 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 | Lacerta |
| Period | 538.5 ms |
| Period derivative | 2.8×10⁻¹⁵ s/s |
| Characteristic age | 3.1 million years |
| Magnetic field | 1.2×10¹² G |
| Spin-down luminosity | 7.0×10³² erg/s |
| Dispersion measure | 43.5 pc/cm³ |
| Distance | 2,383 pc (7.8 thousand ly) |
| Discovery | 1969 · misc, gb1, gb3, gb4, gbncc, jb1, lotaas, fast_gpps |
| Source | ATNF Pulsar Catalogue |
| Right ascension (J2000) | 22h 19m 48.1s |
| Declination (J2000) | +47° 54′ 54″ |
In the sky
Visible from the whole Northern Hemisphere and south to latitude 42° S. North of latitude 42° N it never sets. It stands highest at midnight in August, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out 7,772 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 138 million years.