Pulsar
PSR J1858-2216
Millisecond pulsar · binary system
A millisecond pulsar spinning 419 times per second: an old neutron star spun up again (“recycled”) by matter transferred from a companion. It shares a 46.083 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 | Sagittarius |
| Period | 2.384 ms (419 Hz) |
| Period derivative | 3.8×10⁻²¹ s/s |
| Characteristic age | 9.9 billion years |
| Magnetic field | 9.6×10⁷ G |
| Spin-down luminosity | 1.1×10³⁴ erg/s |
| Dispersion measure | 26.6 pc/cm³ |
| Distance | 921 pc (3.0 thousand ly) |
| Companion | helium white dwarf (estimated), ~0.25 M☉ |
| Orbital period | 46.083 days |
| Eccentricity | 0.000131 |
| Discovery | 2016 · FermiAssoc |
| Source | ATNF Pulsar Catalogue |
| Right ascension (J2000) | 18h 58m 17.9s |
| Declination (J2000) | −22° 16′ 56″ |
In the sky
Visible from the whole Southern Hemisphere and north to latitude 68° N. South of latitude 68° S 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 around 979 BC. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 53 million years.