BBC Sky at Night - UK (2021-08)

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6 BBC Sky at Night Magazine August 2021

This glowing shell, 4,300 lightyears away in

the constellation of Scorpius, the Scorpion

may offer us a glimpse into how new stars

formed in the early Universe.

Emission nebula RCW 120 is sculpted

by stellar winds blasting from an immense

star at its heart. In this new composite

of data from NASA’s Stratospheric

Observatory for Infrared Astronomy

(SOFIA) and the now-defunct Spitzer

Space Telescope, blue shows the gas

expanding towards Earth; red is the gas

travelling away.

New research has measured the

expansion speed of the glowing gas and

found it to be moving at 53,000km/h.

When it hits the surrounding medium, the

gas compresses, triggering the formation

of dense clumps along the nebula’s rim,

areas jam-packed with new stars.

The blistering velocity of expansion

suggests star formation can be a far more

fast and furious process than previously

thought. It also shows that RCW 120

is something of a whippersnapper – a

youthful 150,000 years old.

SOFIA/SPITZER SPACE TELESCOPE, 4 JUNE 2021

Super-fast stellar winds in RCW 120 are triggering star

creation more rapidly than we thought possible

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