Extreme object

Hulse-Taylor pulsar

Hulse-Taylor pulsar is a pulsar 21 000 light-years away, weighing 1.44 Suns, turning 16.9 times a second.

Two neutron stars circling each other every 7.75 hours, spiralling inward exactly as Einstein's gravitational waves demand. It won the 1993 Nobel Prize, twenty-two years before the waves were heard directly.

Key facts

Kind

Pulsar

Distance

21 000 light-years

Mass

1.44 Suns

Turns once every

59.03 milliseconds

See it from here

Too faint for the eye; a telescope, or a long photograph, shows it.

How the map draws it

Drawn as a ring at its measured distance; a black hole has no shape to draw and a pulsar is far too small — the kind of thing, not this exact one · its blink is drawn 10 times slower than it turns, so that an eye can follow it.