Pulsar
PSR B1805-20 (J1808-2057)
Radio pulsar
A neutron star spinning once every 0.918 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 | 918.4 ms |
| Period derivative | 1.7×10⁻¹⁴ s/s |
| Characteristic age | 852 thousand years |
| Magnetic field | 4.0×10¹² G |
| Spin-down luminosity | 8.7×10³² erg/s |
| Dispersion measure | 606.8 pc/cm³ |
| Distance | 4,586 pc (15.0 thousand ly) |
| Discovery | 1986 · jb2, htru_pks, pks1, pksmb |
| Source | ATNF Pulsar Catalogue |
| Right ascension (J2000) | 18h 08m 06.4s |
| Declination (J2000) | −20° 58′ 08″ |
In the sky
Visible from the whole Southern Hemisphere and north to latitude 69° N. South of latitude 69° 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 15 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 265 million years.