Pulsar
PSR J1757-1854
Millisecond pulsar · binary system
A millisecond pulsar spinning 47 times per second: an old neutron star spun up again (“recycled”) by matter transferred from a companion. It shares a 4.40 h orbit with a neutron star. Period, spin-down, distance and orbit come from the ATNF Pulsar Catalogue; the beam geometry is illustrative.
| Type | Pulsar |
|---|---|
| Constellation | Sagittarius |
| Period | 21.497 ms (47 Hz) |
| Period derivative | 2.6×10⁻¹⁸ s/s |
| Characteristic age | 130 million years |
| Magnetic field | 7.6×10⁹ G |
| Spin-down luminosity | 1.0×10³⁴ erg/s |
| Dispersion measure | 378.2 pc/cm³ |
| Distance | 19,560 pc (63.8 thousand ly) |
| Companion | neutron star (estimated), ~1.74 M☉ |
| Orbital period | 4.40 h |
| Eccentricity | 0.6058 |
| Discovery | 2018 · htru_pks |
| Source | ATNF Pulsar Catalogue |
| Right ascension (J2000) | 17h 57m 03.8s |
| Declination (J2000) | −18° 54′ 03″ |
In the sky
Visible from the whole Southern Hemisphere and north to latitude 71° N. South of latitude 71° 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 64 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 1.1 billion years.