Pulsar
PSR B1855+02 (J1857+0212)
Radio pulsar
A neutron star spinning once every 0.416 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 | Serpens |
| Period | 415.9 ms |
| Period derivative | 4.0×10⁻¹⁴ s/s |
| Characteristic age | 164 thousand years |
| Magnetic field | 4.1×10¹² G |
| Spin-down luminosity | 2.2×10³⁴ erg/s |
| Dispersion measure | 504.9 pc/cm³ |
| Distance | 8,000 pc (26.1 thousand ly) |
| Discovery | 1986 · jb2, misc, palfa, pksmb, fast_gpps |
| Source | ATNF Pulsar Catalogue |
| Right ascension (J2000) | 18h 57m 43.6s |
| Declination (J2000) | +2° 12′ 41″ |
In the sky
Visible from the whole Northern Hemisphere and south to latitude 88° S. 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 26 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 463 million years.