Pulsar
PSR J1751-2857
Millisecond pulsar · binary system
A millisecond pulsar spinning 255 times per second: an old neutron star spun up again (“recycled”) by matter transferred from a companion. It shares a 111 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 | Sagittarius |
| Period | 3.915 ms (255 Hz) |
| Period derivative | 1.1×10⁻²⁰ s/s |
| Characteristic age | 5.5 billion years |
| Magnetic field | 2.1×10⁸ G |
| Spin-down luminosity | 7.4×10³³ erg/s |
| Dispersion measure | 42.8 pc/cm³ |
| Distance | 1,088 pc (3.5 thousand ly) |
| Companion | helium white dwarf (estimated), ~0.23 M☉ |
| Orbital period | 111 days |
| Eccentricity | 0.000128 |
| Discovery | 2005 · pksmb, htru_pks |
| Source | ATNF Pulsar Catalogue |
| Right ascension (J2000) | 17h 51m 32.7s |
| Declination (J2000) | −28° 57′ 46″ |
In the sky
Visible from the whole Southern Hemisphere and north to latitude 61° N. South of latitude 61° 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 around 1524 BC. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 63 million years.