Pulsar
PSR J1840+0012_P
Millisecond pulsar · binary system
A millisecond pulsar spinning 187 times per second: an old neutron star spun up again (“recycled”) by matter transferred from a companion. It shares a 7.89 h 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 | Serpens |
| Period | 5.339 ms (187 Hz) |
| Period derivative | 1.3×10⁻²⁰ s/s |
| Characteristic age | 6.6 billion years |
| Magnetic field | 2.7×10⁸ G |
| Spin-down luminosity | 3.3×10³³ erg/s |
| Dispersion measure | 100.8 pc/cm³ |
| Distance | 3,514 pc (11.5 thousand ly) |
| Companion | helium white dwarf (estimated), ~0.17 M☉ |
| Orbital period | 7.89 h |
| Eccentricity | 0.000035 |
| Discovery | 2021 · fast_gpps |
| Source | ATNF Pulsar Catalogue |
| Right ascension (J2000) | 18h 40m 49.2s |
| Declination (J2000) | +0° 12′ 30″ |
In the sky
Visible from the whole Southern Hemisphere and north to latitude 90° N. 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 203 million years.