Pulsar
PSR J2140-2310A
Millisecond pulsar · in the globular cluster M30(NGC7099)
A millisecond pulsar spinning 91 times per second: an old neutron star spun up again (“recycled”) by matter transferred from a companion. It shares a 4.18 h 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 | Capricornus |
| Period | 11.019 ms (91 Hz) |
| Dispersion measure | 25.1 pc/cm³ |
| Distance | 8,460 pc (27.6 thousand ly) |
| Location | in the globular cluster M30(NGC7099) |
| Companion | helium white dwarf (estimated), ~0.12 M☉ |
| Orbital period | 4.18 h |
| Discovery | 2004 · misc |
| Source | ATNF Pulsar Catalogue |
| Right ascension (J2000) | 21h 40m 22.4s |
| Declination (J2000) | −23° 10′ 49″ |
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 August, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out 28 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 489 million years.