Melotte 15 in Cassiopeia
Distance: 7,500 Light Years away from our Sun
The crucible of star formation lies within giant molecular clouds scattered throughout the spiral arms of galaxies. In our own galaxy some of the best known star forming regions lie in a chain of HII clouds located in the Perseus spiral arm of our galaxy.
From west to east the chain of giant HII regions are known as W3, W4, and W5, which are also catalogued as IC 1795, IC 1805, and IC 1848. These nebulae are physically linked (radio observations show a bridge between IC 1805 and IC 1848 confirming a physical connection between the two nebulae) and together extend some 490 light years across the massive Perseus spiral arm.—[**]
The central cluster has the same designation of its parent cloud IC 1805, but is also known as Melotte 15, object number 15 in the catalogue of star clusters by the British-Belgian astronomer Philibert Jacques Melotte (1880-1961).
Image Copyright: Martin Pugh