Pulsar
PSR J1937+1658
Millisecond pulsar · binary system
A millisecond pulsar spinning 253 times per second: an old neutron star spun up again (“recycled”) by matter transferred from a companion. It shares a 17.306 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 | Sagitta |
| Period | 3.958 ms (253 Hz) |
| Period derivative | 1.3×10⁻²⁰ s/s |
| Characteristic age | 4.8 billion years |
| Magnetic field | 2.3×10⁸ G |
| Spin-down luminosity | 8.4×10³³ erg/s |
| Dispersion measure | 105.8 pc/cm³ |
| Distance | 3,258 pc (10.6 thousand ly) |
| Companion | helium white dwarf (estimated), ~0.22 M☉ |
| Orbital period | 17.306 days |
| Eccentricity | 0.000092 |
| Discovery | 2019 · palfa, fast_gpps |
| Source | ATNF Pulsar Catalogue |
| Right ascension (J2000) | 19h 37m 24.9s |
| Declination (J2000) | +16° 58′ 43″ |
In the sky
Visible from the whole Northern Hemisphere and south to latitude 73° S. North of latitude 73° N it never sets. 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 11 thousand 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 189 million years.