Pulsar
PSR J1904+0412
Radio pulsar · binary system
A neutron star spinning once every 0.071 seconds; the beams from its magnetic poles sweep across Earth on every turn. It shares a 14.934 days 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 | Aquila |
| Period | 71.095 ms (14 Hz) |
| Period derivative | 1.1×10⁻¹⁹ s/s |
| Characteristic age | 10.2 billion years |
| Magnetic field | 2.8×10⁹ G |
| Spin-down luminosity | 1.2×10³¹ erg/s |
| Dispersion measure | 185.9 pc/cm³ |
| Distance | 4,590 pc (15.0 thousand ly) |
| Companion | helium white dwarf (estimated), ~0.26 M☉ |
| Orbital period | 14.934 days |
| Eccentricity | 0.000220 |
| Discovery | 2001 · pksmb, palfa, fast_gpps |
| Source | ATNF Pulsar Catalogue |
| Right ascension (J2000) | 19h 04m 31.4s |
| Declination (J2000) | +4° 12′ 06″ |
In the sky
Visible from the whole Northern Hemisphere and south to latitude 86° 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 15 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 266 million years.