The Soul Nebula (Westerhout 5) is an emission nebula located in the constellation Cassiopeia. It forms a famous pair known as the Heart and Soul with the neighbouring Heart Nebula (IC 1805). The Soul Nebula is sometimes also known as the Embryo Nebula or IC 1848, which is a designation used for the open star cluster embedded within the nebula.
The Heart and Soul Nebulae complex spans an area about 300 light years across and is a vast star-forming region illuminated by the light of the young stars surrounded by star-forming clouds of dust and gas. The two large clouds are separated by only 2.5 degrees and physically connected by a bridge of gas. The stars in the region are less than a few million years old and are only beginning their life. For comparison, our Sun has been around for almost 5 billion years.
The Soul Nebula is about 100 light years across and has an estimated age of 1 million years. It contains several small open stars clusters. IC 1848 is embedded in the body of the nebula, while the clusters CR 34, 632 and 634 can be seen in the head. Small emission nebulae IC 1871, 670 and 669 are located just next to the Soul Nebula.
The Soul Nebula is being carved out by the stellar winds from the stars embedded within it, a process that leaves behind large pillars of material pointing inwards. These pillars are very dense and have stars forming at their tips. Each pillar spans about 10 light years.
The nebula is home to W5, a radio source that spans an area roughly the size of four full Moons. The radio source has large cavities that are the result of the nearby massive stars’ winds and radiation carving the nebula, pushing the gas together and causing it to ignite to form new stars.
Studies of the region have shown that the stars are progressively and systematically younger the more distant they are from the centre of these cavities.
The Soul Nebula lies in the vicinity of several notable deep sky objects: the galaxies Maffei 1 and Maffei 2, the Fishhead Nebula (IC 1795), and the famous Double Cluster in Perseus.
Soul Nebula – Westerhout 5
Right ascension: 02h 55m 24s
Apparent size: 150′ x 75′
Distance: 7,500 light years
Absolute magnitude: 6.5
Designations: Soul Nebula, Westerhout 5, Embryo Nebula, Sharpless 2-199, Sh2-199, LBN 667, IC 1848 (open cluster)