Pulsar
PSR J1709+2313
Millisecond pulsar · binary system
A millisecond pulsar spinning 216 times per second: an old neutron star spun up again (“recycled”) by matter transferred from a companion. It shares a 22.712 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 | Hercules |
| Period | 4.631 ms (216 Hz) |
| Period derivative | 3.6×10⁻²¹ s/s |
| Characteristic age | 20.2 billion years |
| Magnetic field | 1.3×10⁸ G |
| Spin-down luminosity | 1.4×10³³ erg/s |
| Dispersion measure | 25.3 pc/cm³ |
| Distance | 2,180 pc (7.1 thousand ly) |
| Companion | helium white dwarf (estimated), ~0.32 M☉ |
| Orbital period | 22.712 days |
| Eccentricity | 0.000019 |
| Discovery | 1995 · ar4, ar327, fast_gpps |
| Source | ATNF Pulsar Catalogue |
| Right ascension (J2000) | 17h 09m 05.8s |
| Declination (J2000) | +23° 13′ 28″ |
In the sky
Visible from the whole Northern Hemisphere and south to latitude 67° S. North of latitude 67° 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 7,110 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 126 million years.