Pulsar
PSR J1740-28
Millisecond pulsar · binary system
A millisecond pulsar spinning 65 times per second: an old neutron star spun up again (“recycled”) by matter transferred from a companion. It shares a 191 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 | Ophiuchus |
| Period | 15.406 ms (65 Hz) |
| Period derivative | 2.8×10⁻¹⁷ s/s |
| Characteristic age | 8.6 million years |
| Magnetic field | 2.1×10¹⁰ G |
| Spin-down luminosity | 3.1×10³⁵ erg/s |
| Dispersion measure | 317.0 pc/cm³ |
| Distance | 6,082 pc (19.8 thousand ly) |
| Companion | helium white dwarf (estimated), ~0.24 M☉ |
| Orbital period | 191 days |
| Eccentricity | 0.3000 |
| Discovery | 2026 · misc |
| Source | ATNF Pulsar Catalogue |
| Right ascension (J2000) | 17h 39m 58.0s |
| Declination (J2000) | −28° 07′ 00″ |
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 20 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 352 million years.