A guide to what's up in the sky for Southern Australia

The Trifid Nebula (1st Jun 2024)

M20 – The Trifid Nebula in Sagittarius

M20, a gem of the winter sky, allows us a view into the exciting science of star birth. M20, just over 4,000 light years from the Sun, is a young star forming region about 30 light years across and is illuminated by the supergiant HD 164492 at the centre of its trilobed emission cloud.

The star is about 30 times the mass of our Sun and is the "A" component of a triple system. As a star-forming region, M20 is similar to M42 in Orion, in its complexity and relationship to its parent molecular cloud but is much younger. A large blue reflection cloud forms the northern border of M20 and is illuminated solely by the supergiant HD 164514.

Recent X-ray and infrared observations have discovered an amazing array of very early stars and protostars within M20 giving us a rare glimpse of the earliest stages of star birth.