Pulsar
PSR J1823-3543
Millisecond pulsar · binary system
A millisecond pulsar spinning 421 times per second: an old neutron star spun up again (“recycled”) by matter transferred from a companion. Its radio beams do not sweep across Earth; its pulses are seen only in X-rays or gamma rays. It shares a 145 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 | 2.373 ms (421 Hz) |
| Period derivative | 2.1×10⁻²⁰ s/s |
| Characteristic age | 1.8 billion years |
| Magnetic field | 2.3×10⁸ G |
| Spin-down luminosity | 6.3×10³⁴ erg/s |
| Dispersion measure | 81.7 pc/cm³ |
| Distance | 3,711 pc (12.1 thousand ly) |
| Companion | helium white dwarf (estimated), ~0.31 M☉ |
| Orbital period | 145 days |
| Eccentricity | 0.000269 |
| Discovery | 2023 · meerkat_trapum |
| Source | ATNF Pulsar Catalogue |
| Right ascension (J2000) | 18h 23m 43.0s |
| Declination (J2000) | −35° 43′ 41″ |
In the sky
Visible from the whole Southern Hemisphere and north to latitude 54° N. South of latitude 54° S it never sets. It stands highest at midnight in June, 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 Homo sapiens was spreading out of Africa; there was no farming yet. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 215 million years.