Pulsar
PSR J1855-1436
Millisecond pulsar · binary system
A millisecond pulsar spinning 278 times per second: an old neutron star spun up again (“recycled”) by matter transferred from a companion. It shares a 61.540 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 | Scutum |
| Period | 3.594 ms (278 Hz) |
| Period derivative | 1.1×10⁻²⁰ s/s |
| Characteristic age | 5.2 billion years |
| Magnetic field | 2.0×10⁸ G |
| Spin-down luminosity | 9.3×10³³ erg/s |
| Dispersion measure | 109.2 pc/cm³ |
| Distance | 5,127 pc (16.7 thousand ly) |
| Companion | helium white dwarf (estimated), ~0.31 M☉ |
| Orbital period | 61.540 days |
| Eccentricity | 0.000297 |
| Discovery | 2016 · FermiAssoc |
| Source | ATNF Pulsar Catalogue |
| Right ascension (J2000) | 18h 55m 54.2s |
| Declination (J2000) | −14° 36′ 09″ |
In the sky
Visible from the whole Southern Hemisphere and north to latitude 75° N. South of latitude 75° S it never sets. It stands highest at midnight in July, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out 17 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 297 million years.