Pulsar
PSR J1921+1929
Millisecond pulsar · binary system
A millisecond pulsar spinning 378 times per second: an old neutron star spun up again (“recycled”) by matter transferred from a companion. It shares a 39.649 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 | Vulpecula |
| Period | 2.646 ms (378 Hz) |
| Period derivative | 3.8×10⁻²⁰ s/s |
| Characteristic age | 1.1 billion years |
| Magnetic field | 3.2×10⁸ G |
| Spin-down luminosity | 8.1×10³⁴ erg/s |
| Dispersion measure | 64.8 pc/cm³ |
| Distance | 2,432 pc (7.9 thousand ly) |
| Companion | helium white dwarf (estimated), ~0.30 M☉ |
| Orbital period | 39.649 days |
| Eccentricity | 0.000208 |
| Discovery | 2019 · palfa, FermiBlind, fast_gpps |
| Source | ATNF Pulsar Catalogue |
| Right ascension (J2000) | 19h 21m 23.4s |
| Declination (J2000) | +19° 29′ 22″ |
In the sky
Visible from the whole Northern Hemisphere and south to latitude 71° S. North of latitude 71° 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 7,932 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 141 million years.