Pulsar
PSR J1836-2354A
Millisecond pulsar · in the globular cluster M22(NGC6656)
A millisecond pulsar spinning 298 times per second: an old neutron star spun up again (“recycled”) by matter transferred from a companion. It shares a 4.87 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 | 3.354 ms (298 Hz) |
| Period derivative | 2.3×10⁻²¹ s/s |
| Characteristic age | 22.9 billion years |
| Magnetic field | 8.9×10⁷ G |
| Spin-down luminosity | 2.4×10³³ erg/s |
| Dispersion measure | 89.1 pc/cm³ |
| Distance | 3,300 pc (10.8 thousand ly) |
| Location | in the globular cluster M22(NGC6656) |
| Companion | very-low-mass companion (estimated), ~0.020 M☉ |
| Orbital period | 4.87 h |
| Discovery | 2011 · misc |
| Source | ATNF Pulsar Catalogue |
| Right ascension (J2000) | 18h 36m 25.4s |
| Declination (J2000) | −23° 54′ 53″ |
In the sky
Visible from the whole Southern Hemisphere and north to latitude 66° N. South of latitude 66° 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 11 thousand 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 191 million years.