Pulsar
PSR J1740-2805
Millisecond pulsar · binary system
A millisecond pulsar spinning 133 times per second: an old neutron star spun up again (“recycled”) by matter transferred from a companion. It shares a 11.61 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 | Ophiuchus |
| Period | 7.507 ms (133 Hz) |
| Period derivative | 1.3×10⁻¹⁹ s/s |
| Characteristic age | 934 million years |
| Magnetic field | 9.9×10⁸ G |
| Spin-down luminosity | 1.2×10³⁴ erg/s |
| Dispersion measure | 330.0 pc/cm³ |
| Distance | 7,009 pc (22.9 thousand ly) |
| Companion | very-low-mass companion (estimated), ~0.060 M☉ |
| Orbital period | 11.61 h |
| Eccentricity | 0.1200 |
| Discovery | 2026 · misc |
| Source | ATNF Pulsar Catalogue |
| Right ascension (J2000) | 17h 40m 06.8s |
| Declination (J2000) | −28° 05′ 33″ |
In the sky
Visible from the whole Southern Hemisphere and north to latitude 62° N. South of latitude 62° 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 23 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 406 million years.