Pulsar
PSR J2115+5448
Millisecond pulsar · binary system
A millisecond pulsar spinning 384 times per second: an old neutron star spun up again (“recycled”) by matter transferred from a companion. It shares a 3.25 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 | Cygnus |
| Period | 2.603 ms (384 Hz) |
| Period derivative | 7.5×10⁻²⁰ s/s |
| Characteristic age | 551 million years |
| Magnetic field | 4.5×10⁸ G |
| Spin-down luminosity | 1.7×10³⁵ erg/s |
| Dispersion measure | 77.4 pc/cm³ |
| Distance | 3,106 pc (10.1 thousand ly) |
| Companion | very-low-mass companion (estimated), ~0.025 M☉ |
| Orbital period | 3.25 h |
| Discovery | 2016 · FermiAssoc |
| Source | ATNF Pulsar Catalogue |
| Right ascension (J2000) | 21h 15m 11.8s |
| Declination (J2000) | +54° 48′ 45″ |
In the sky
Visible from the whole Northern Hemisphere and south to latitude 35° S. North of latitude 35° N 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 10 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 180 million years.