Pulsar
PSR J0740+6620
Millisecond pulsar · binary system
A millisecond pulsar spinning 347 times per second: an old neutron star spun up again (“recycled”) by matter transferred from a companion. It shares a 4.767 days orbit with a helium white dwarf. Period, spin-down, distance and orbit come from the ATNF Pulsar Catalogue; the beam geometry is illustrative.
| Type | Pulsar |
|---|---|
| Constellation | Camelopardalis |
| Period | 2.886 ms (347 Hz) |
| Period derivative | 1.2×10⁻²⁰ s/s |
| Characteristic age | 3.8 billion years |
| Magnetic field | 1.9×10⁸ G |
| Spin-down luminosity | 2.0×10³⁴ erg/s |
| Dispersion measure | 15.0 pc/cm³ |
| Distance | 1,150 pc (3.8 thousand ly) |
| Companion | helium white dwarf (estimated), ~0.23 M☉ |
| Orbital period | 4.767 days |
| Eccentricity | 0.000006 |
| Discovery | 2014 · gbncc, FermiBlind |
| Source | ATNF Pulsar Catalogue |
| Right ascension (J2000) | 7h 40m 45.8s |
| Declination (J2000) | +66° 20′ 33″ |
In the sky
Visible from the whole Northern Hemisphere and south to latitude 24° S. North of latitude 24° N it never sets. It stands highest at midnight in January, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out around 1726 BC. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 67 million years.