Guided sky tour · 8 stops · about 2 minutes

Pulsars and their glitches

Spinning neutron stars that tick like clocks, then suddenly speed up: lighthouses, glitches, black widows and magnetars.

Take it on the live map

Sit back: it plays by itself. Space pauses, ← → move, reads it aloud.

PSR B1919+21 (LGM-1): a sky-survey photograph of its field

PSR B1919+21 (LGM-1) · 2,300 light-years

Stop 1 of 8

"Little green men"

In 1967 Jocelyn Bell Burnell, a student in Cambridge, found a radio signal ticking every 1.34 seconds. Nicknamed LGM-1, for "little green men", it was the first pulsar: a spinning neutron star.

2,300 light-years light left 2,300 years ago, around 275 BC

Explore it on the map PSR B1919+21 (LGM-1)'s page

Crab Pulsar (PSR B0531+21): a sky-survey photograph of its field

Crab Pulsar (PSR B0531+21) · 6,500 light-years

Stop 2 of 8

A cosmic lighthouse

A neutron star's magnetic poles beam radio waves into space. Its magnetic axis is tilted from its spin axis, so the beams sweep round like a lighthouse's, and each time one crosses Earth we see a pulse. The Crab Pulsar turns 30 times a second.

6,500 light-years light left 6,500 years ago, around 4,475 BC

Explore it on the map Crab Pulsar (PSR B0531+21)'s page

Vela Pulsar: a sky-survey photograph of its field

Vela Pulsar · 960 light-years

Stop 3 of 8

A glitch

Pulsars slow down very steadily, yet some suddenly spin faster: a glitch. The Vela Pulsar, turning 11 times a second, glitches every two or three years, probably when the superfluid deep inside the neutron star suddenly passes some of its spin to the crust.

960 light-years light left 960 years ago, around AD 1066

Explore it on the map Vela Pulsar's page

Geminga (PSR J0633+1746): a sky-survey photograph of its field

Geminga (PSR J0633+1746) · 800 light-years

Stop 4 of 8

A pulsar without radio

Geminga, about 800 light-years away, was found as a gamma-ray source in 1972 and recognised as a pulsar only in 1992. Its radio beams miss Earth, so we see it pulse in gamma rays and X-rays instead.

800 light-years light left 800 years ago, around AD 1226

Explore it on the map Geminga (PSR J0633+1746)'s page

PSR J0437-4715: a sky-survey photograph of its field

PSR J0437-4715 · 510 light-years

Stop 5 of 8

Spun up to a blur

Millisecond pulsars have been spun up by pulling gas off a companion star. PSR J0437-4715 turns 174 times a second and keeps time almost as well as an atomic clock.

510 light-years light left 510 years ago, around AD 1516

Explore it on the map PSR J0437-4715's page

Black Widow Pulsar: a sky-survey photograph of its field

Black Widow Pulsar · 6,500 light-years

Stop 6 of 8

The Black Widow

The Black Widow Pulsar earned its name: its wind of particles and radiation is slowly boiling away its small companion star.

6,500 light-years light left 6,500 years ago, around 4,475 BC

Explore it on the map Black Widow Pulsar's page

SGR 1935+2154: a sky-survey photograph of its field

SGR 1935+2154 · 30,000 light-years

Stop 7 of 8

Magnetars

Magnetars are neutron stars with the strongest magnets known. In April 2020 SGR 1935+2154 gave off a fast radio burst, the first ever seen from inside our galaxy, which tied these mysterious bursts to magnetars.

30,000 light-years light left 30,000 years ago

Explore it on the map SGR 1935+2154's page

The Milky Way towards its centre

Stop 8 of 8

Thousands of them

About 4,500 pulsars are known; the map now shows them all. Most lie along the Milky Way, where the heavy stars that made them were born. Pick any dot to see its spin and distance.

Explore it on the map

Tour complete

Pulsars and their glitches

Next tour: Cosmic oddities All tours