IN THE HEART OF THE TARANTULA

Fittingly, the heaviest star we know of lies at the centre of the largest star-forming region in the nearby universe

The gargantuan R136a1 and its nearby neighbours have an enormous effect on their surroundings. By pumping out huge amounts of ultraviolet radiation, they excite gas atoms and molecules within the Tarantula Nebula, boosting the energy of their electrons, which then return to their normal state through the emission of visible light. So far as astronomers can tell, none of these massive stars have a binary companion, so we cannot measure their effect on orbiting objects directly. However, their overall gravity is enough to ensure the enormous R136 cluster will not slowly drift apart like most open clusters. Instead, as its largest stars reach the ends of their lives, while its more sedate ones persist, the body will slowly evolve into a globular cluster of long-lived red and yellow stars.

1

Blurred together

A crowded grouping of stars known as R136 appears as a single brilliant object through most telescopes.

2

Monster factory

The enormous amounts of gas in the Tarantula Nebula give rise to massive stars that end their lives in supernova explosions. In 1987 its outlying regions were host to the most recent naked-eye supernova.

3

Crowded heart

The R136 cluster is rich in heavyweight blue stars and generates most of the energy of the nebula.

This stunning Hubble Space Telescope image offers a view of the R136 region, home to the heaviest known stars. As well as R136a1, the cluster also contains R136a2, which has up to 150 solar masses