Pulsar
PSR J1921+1652_P
Millisecond pulsar · binary system
A millisecond pulsar spinning 272 times per second: an old neutron star spun up again (“recycled”) by matter transferred from a companion. It shares a 2.702 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 | 3.680 ms (272 Hz) |
| Dispersion measure | 124.1 pc/cm³ |
| Distance | 3,634 pc (11.9 thousand ly) |
| Companion | helium white dwarf (estimated), ~0.13 M☉ |
| Orbital period | 2.702 days |
| Discovery | 2025 · fast_gpps |
| Source | ATNF Pulsar Catalogue |
| Right ascension (J2000) | 19h 21m 34.0s |
| Declination (J2000) | +16° 52′ 00″ |
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 12 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 210 million years.