Monkey Head Nebula

In a corner of the constellation Orion, the profile of a big monkey seems to loom out of the clouds of gas: that is what astrophotographers have seen in this nebula, about 6,400 light-years from us. The resemblance is only a play of light and shadow, but once you have seen it, it is hard to forget.

The Monkey Head is an H II region: a vast stellar nursery, an immense cloud of hydrogen that shines with its own light and where new stars are forming. It owes its glow to a young, massive star, fifteen to thirty times heavier than the Sun, whose intense ultraviolet radiation makes the gas glow. It is this same energy that slowly sculpts the pillars of dust standing within the nebula.

In the sky the nebula is surprisingly large, wider than the full Moon, and measures about 75 light-years across in real space. It goes hand in hand with a young star cluster, NGC 2175, whose members are only a few million years old and keep eroding and shaping the gas around them.

Frenchman Édouard Stephan first spotted it from Marseille in 1877. Closer to our time, in 2014, the Hubble Space Telescope devoted its anniversary image to it, revealing in close-up the pillars of dust where stars are born.