Pulsar
PSR J2129-5721
Millisecond pulsar · binary system
A millisecond pulsar spinning 268 times per second: an old neutron star spun up again (“recycled”) by matter transferred from a companion. It shares a 6.625 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 | Indus |
| Period | 3.726 ms (268 Hz) |
| Period derivative | 2.1×10⁻²⁰ s/s |
| Characteristic age | 2.8 billion years |
| Magnetic field | 2.8×10⁸ G |
| Spin-down luminosity | 1.6×10³⁴ erg/s |
| Dispersion measure | 31.8 pc/cm³ |
| Distance | 3,200 pc (10.4 thousand ly) |
| Companion | helium white dwarf (estimated), ~0.15 M☉ |
| Orbital period | 6.625 days |
| Eccentricity | 0.000012 |
| Discovery | 1996 · pks70 |
| Source | ATNF Pulsar Catalogue |
| Right ascension (J2000) | 21h 29m 22.8s |
| Declination (J2000) | −57° 21′ 14″ |
In the sky
Visible from the whole Southern Hemisphere and north to latitude 33° N. South of latitude 33° S it never sets. It stands highest at midnight in August, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out 10 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 185 million years.