Pulsar
PSR J1905+0154A
Millisecond pulsar · in the globular cluster NGC6749
A millisecond pulsar spinning 313 times per second: an old neutron star spun up again (“recycled”) by matter transferred from a companion. It shares a 19.50 h 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 | Aquila |
| Period | 3.193 ms (313 Hz) |
| Dispersion measure | 193.7 pc/cm³ |
| Distance | 7,600 pc (24.8 thousand ly) |
| Location | in the globular cluster NGC6749 |
| Companion | helium white dwarf (estimated), ~0.10 M☉ |
| Orbital period | 19.50 h |
| Discovery | 2007 · misc |
| Source | ATNF Pulsar Catalogue |
| Right ascension (J2000) | 19h 05m 15.4s |
| Declination (J2000) | +1° 54′ 33″ |
In the sky
Visible from the whole Northern Hemisphere and south to latitude 88° S. 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 25 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 440 million years.