Pulsar
PSR J1755-2550
Radio pulsar · binary system
A neutron star spinning once every 0.315 seconds; the beams from its magnetic poles sweep across Earth on every turn. It shares a 9.696 days orbit with a CO white dwarf. Period, spin-down, distance and orbit come from the ATNF Pulsar Catalogue; the beam geometry is illustrative.
| Type | Pulsar |
|---|---|
| Constellation | Sagittarius |
| Period | 315.2 ms |
| Period derivative | 2.4×10⁻¹⁵ s/s |
| Characteristic age | 2.1 million years |
| Magnetic field | 8.9×10¹¹ G |
| Spin-down luminosity | 3.1×10³³ erg/s |
| Dispersion measure | 750.9 pc/cm³ |
| Distance | 4,891 pc (16.0 thousand ly) |
| Companion | CO white dwarf (estimated), ~0.48 M☉ |
| Orbital period | 9.696 days |
| Eccentricity | 0.0894 |
| Discovery | 2015 · htru_pks |
| Source | ATNF Pulsar Catalogue |
| Right ascension (J2000) | 17h 55m 38.4s |
| Declination (J2000) | −25° 50′ 22″ |
In the sky
Visible from the whole Southern Hemisphere and north to latitude 64° N. South of latitude 64° 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 16 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 283 million years.