Pulsar
PSR B1820-11 (J1823-1115)
Radio pulsar · binary system
A neutron star spinning once every 0.280 seconds; the beams from its magnetic poles sweep across Earth on every turn. It shares a 358 days orbit with a CO white dwarf. Period, spin-down, distance and orbit come from the ATNF Pulsar Catalogue; the beam geometry is illustrative.
| Type | Pulsar |
|---|---|
| Constellation | Scutum |
| Period | 279.8 ms |
| Period derivative | 1.4×10⁻¹⁵ s/s |
| Characteristic age | 3.2 million years |
| Magnetic field | 6.3×10¹¹ G |
| Spin-down luminosity | 2.5×10³³ erg/s |
| Dispersion measure | 428.6 pc/cm³ |
| Distance | 5,352 pc (17.5 thousand ly) |
| Companion | CO white dwarf (estimated), ~0.78 M☉ |
| Orbital period | 358 days |
| Eccentricity | 0.7946 |
| Discovery | 1986 · jb2, htru_pks, pksmb |
| Source | ATNF Pulsar Catalogue |
| Right ascension (J2000) | 18h 23m 40.3s |
| Declination (J2000) | −11° 15′ 11″ |
In the sky
Visible from the whole Southern Hemisphere and north to latitude 79° N. South of latitude 79° 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 17 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 310 million years.