Pulsar
PSR J1807-2459A
Millisecond pulsar · in the globular cluster NGC6544
A millisecond pulsar spinning 327 times per second: an old neutron star spun up again (“recycled”) by matter transferred from a companion. It shares a 1.71 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 | 3.059 ms (327 Hz) |
| Dispersion measure | 134.0 pc/cm³ |
| Distance | 2,580 pc (8.4 thousand ly) |
| Location | in the globular cluster NGC6544 |
| Companion | very-low-mass companion (estimated), ~0.010 M☉ |
| Orbital period | 1.71 h |
| Discovery | 2001 · pksgc, htru_pks, pksmb |
| Source | ATNF Pulsar Catalogue |
| Right ascension (J2000) | 18h 07m 20.4s |
| Declination (J2000) | −24° 59′ 53″ |
In the sky
Visible from the whole Southern Hemisphere and north to latitude 65° N. South of latitude 65° 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 8,415 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 149 million years.