Pulsar
PSR J1745-23
Millisecond pulsar · binary system
A millisecond pulsar spinning 185 times per second: an old neutron star spun up again (“recycled”) by matter transferred from a companion. It shares a 3.97 h orbit with a very-low-mass companion. Period, spin-down, distance and orbit come from the ATNF Pulsar Catalogue; the beam geometry is illustrative.
| Type | Pulsar |
|---|---|
| Constellation | Sagittarius |
| Period | 5.417 ms (185 Hz) |
| Dispersion measure | 244.9 pc/cm³ |
| Distance | 7,941 pc (25.9 thousand ly) |
| Companion | very-low-mass companion (estimated), ~0.030 M☉ |
| Orbital period | 3.97 h |
| Discovery | 2020 · htru_pks |
| Source | ATNF Pulsar Catalogue |
| Right ascension (J2000) | 17h 45m 30.0s |
| Declination (J2000) | −23° 25′ 00″ |
In the sky
Visible from the whole Southern Hemisphere and north to latitude 67° N. South of latitude 67° 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 26 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 459 million years.