Pulsar
PSR J1850+0242
Millisecond pulsar · binary system
A millisecond pulsar spinning 223 times per second: an old neutron star spun up again (“recycled”) by matter transferred from a companion. It shares a 17.65 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 | 4.480 ms (223 Hz) |
| Period derivative | 1.6×10⁻¹⁹ s/s |
| Characteristic age | 437 million years |
| Magnetic field | 8.6×10⁸ G |
| Spin-down luminosity | 7.1×10³⁴ erg/s |
| Dispersion measure | 540.1 pc/cm³ |
| Distance | 12,310 pc (40.2 thousand ly) |
| Companion | helium white dwarf (estimated), ~0.084 M☉ |
| Orbital period | 17.65 h |
| Eccentricity | 0.000090 |
| Discovery | 2015 · palfa |
| Source | ATNF Pulsar Catalogue |
| Right ascension (J2000) | 18h 50m 41.7s |
| Declination (J2000) | +2° 42′ 58″ |
In the sky
Visible from the whole Northern Hemisphere and south to latitude 87° S. It stands highest at midnight in July, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out 40 thousand years ago. At that time Homo sapiens was spreading out of Africa; there was no farming yet. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 712 million years.