Image 6-3
Hourglass Nebula

This is a Hubble Space Telescope image of MyCn18, also known as the Hourglass Nebula. It is a planetary nebula located about 8,000 light-years from Earth in the constellation Musca. This image reveals the true shape of MyCn18 to be an hourglass with an intricate pattern of etchings in its walls. This image sheds new light on the poorly understood process of ejection of stellar matter which accompanies the slow death of Sun-like stars. The hourglass shape is produced by the expansion of stellar wind within a slowly expanding cloud which is more dense near its equator than near its poles.