Pulsar
PSR B2241+69 (J2242+6950)
Radio pulsar
A neutron star spinning once every 1.66 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 | Cepheus |
| Period | 1.665 s |
| Period derivative | 4.8×10⁻¹⁵ s/s |
| Characteristic age | 5.5 million years |
| Magnetic field | 2.9×10¹² G |
| Spin-down luminosity | 4.1×10³¹ erg/s |
| Dispersion measure | 40.9 pc/cm³ |
| Distance | 2,008 pc (6.5 thousand ly) |
| Discovery | 1985 · gb2, gbncc, lotaas |
| Source | ATNF Pulsar Catalogue |
| Right ascension (J2000) | 22h 42m 56.4s |
| Declination (J2000) | +69° 50′ 52″ |
In the sky
Visible from the whole Northern Hemisphere and south to latitude 20° S. North of latitude 20° N it never sets. It stands highest at midnight in August, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out 6,549 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 116 million years.