Pulsar
PSR J1957+2516
Millisecond pulsar · binary system
A millisecond pulsar spinning 252 times per second: an old neutron star spun up again (“recycled”) by matter transferred from a companion. It shares a 5.72 h 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 | Vulpecula |
| Period | 3.962 ms (252 Hz) |
| Period derivative | 2.7×10⁻²⁰ s/s |
| Characteristic age | 2.3 billion years |
| Magnetic field | 3.3×10⁸ G |
| Spin-down luminosity | 1.7×10³⁴ erg/s |
| Dispersion measure | 44.1 pc/cm³ |
| Distance | 2,659 pc (8.7 thousand ly) |
| Companion | helium white dwarf (estimated), ~0.11 M☉ |
| Orbital period | 5.72 h |
| Eccentricity | 0.000028 |
| Discovery | 2015 · palfa, FermiAssoc |
| Source | ATNF Pulsar Catalogue |
| Right ascension (J2000) | 19h 57m 34.6s |
| Declination (J2000) | +25° 16′ 02″ |
In the sky
Visible from the whole Northern Hemisphere and south to latitude 65° S. North of latitude 65° 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 8,673 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 154 million years.