The darkness

摘要

Galaxies are supposed to be glittering jewels, studded with billions of bright stars and glowing nebulae. Not so Segue 1, the dark horse of the galactic neighbourhood. Segue 1 is only 75,000 light years away, making it a near neighbour of the Milky Way, yet it remained undiscovered until 2006 because its total light emission is only 300 times that of our sun.