Pulsar
PSR B1839+56 (J1840+5640)
Radio pulsar
A neutron star spinning once every 1.65 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 | Draco |
| Period | 1.653 s |
| Period derivative | 1.5×10⁻¹⁵ s/s |
| Characteristic age | 18 million years |
| Magnetic field | 1.6×10¹² G |
| Spin-down luminosity | 1.3×10³¹ erg/s |
| Dispersion measure | 26.8 pc/cm³ |
| Distance | 1,580 pc (5.2 thousand ly) |
| Discovery | 1980 · misc, gb4, gbncc, lotaas |
| Source | ATNF Pulsar Catalogue |
| Right ascension (J2000) | 18h 40m 44.5s |
| Declination (J2000) | +56° 40′ 55″ |
In the sky
Visible from the whole Northern Hemisphere and south to latitude 33° S. North of latitude 33° N 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 5,153 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 91 million years.