Eye on the sky

Super-fast stellar winds in RCW 120 are triggering star creation more rapidly than we thought possible

SOFIA/SPITZER SPACE TELESCOPE, 4 JUNE 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.