Pulsar
PSR B1821-19 (J1824-1945)
Radio pulsar
A neutron star spinning once every 0.189 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 | Sagittarius |
| Period | 189.3 ms |
| Period derivative | 5.2×10⁻¹⁵ s/s |
| Characteristic age | 573 thousand years |
| Magnetic field | 1.0×10¹² G |
| Spin-down luminosity | 3.0×10³⁴ erg/s |
| Dispersion measure | 224.3 pc/cm³ |
| Distance | 3,700 pc (12.1 thousand ly) |
| Discovery | 1978 · mol2, htru_pks, misc, pks1, pks70, pksmb |
| Source | ATNF Pulsar Catalogue |
| Right ascension (J2000) | 18h 24m 00.5s |
| Declination (J2000) | −19° 46′ 03″ |
In the sky
Visible from the whole Southern Hemisphere and north to latitude 70° N. South of latitude 70° S it never sets. It stands highest at midnight in June, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out 12 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 214 million years.