Pulsar
PSR B1620-26 (J1623-2631)
Millisecond pulsar · in the globular cluster NGC6121(M4)
A millisecond pulsar spinning 90 times per second: an old neutron star spun up again (“recycled”) by matter transferred from a companion. It shares a 191 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 | Scorpius |
| Period | 11.076 ms (90 Hz) |
| Period derivative | 6.7×10⁻¹⁹ s/s |
| Characteristic age | 262 million years |
| Magnetic field | 2.8×10⁹ G |
| Spin-down luminosity | 1.9×10³⁴ erg/s |
| Dispersion measure | 62.9 pc/cm³ |
| Distance | 1,851 pc (6.0 thousand ly) |
| Location | in the globular cluster NGC6121(M4) |
| Companion | helium white dwarf (estimated), ~0.33 M☉ |
| Orbital period | 191 days |
| Eccentricity | 0.0253 |
| Discovery | 1988 · misc, jb1, pks70, pkssw |
| Source | ATNF Pulsar Catalogue |
| Right ascension (J2000) | 16h 23m 38.2s |
| Declination (J2000) | −26° 31′ 54″ |
In the sky
Visible from the whole Southern Hemisphere and north to latitude 63° N. South of latitude 63° S it never sets. It stands highest at midnight in May, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out 6,037 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 107 million years.