Pulsar
PSR J1807-2459B
Millisecond pulsar · in the globular cluster NGC6544
A millisecond pulsar spinning 239 times per second: an old neutron star spun up again (“recycled”) by matter transferred from a companion. It shares a 9.957 days orbit with a neutron star. Period, spin-down, distance and orbit come from the ATNF Pulsar Catalogue; the beam geometry is illustrative.
| Type | Pulsar |
|---|---|
| Constellation | Sagittarius |
| Period | 4.186 ms (239 Hz) |
| Period derivative | 8.2×10⁻²⁰ s/s |
| Characteristic age | 806 million years |
| Magnetic field | 5.9×10⁸ G |
| Spin-down luminosity | 4.4×10³⁴ erg/s |
| Dispersion measure | 137.2 pc/cm³ |
| Distance | 2,580 pc (8.4 thousand ly) |
| Location | in the globular cluster NGC6544 |
| Companion | neutron star (estimated), ~1.48 M☉ |
| Orbital period | 9.957 days |
| Eccentricity | 0.7470 |
| Discovery | 2003 · misc |
| Source | ATNF Pulsar Catalogue |
| Right ascension (J2000) | 18h 07m 20.9s |
| Declination (J2000) | −25° 00′ 02″ |
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.