A heart needs a soul. Love is in the universe. Heart Nebula is an emission nebula which looks like a human heart and it glows brightly in red color due to its most prominent element Hydrogen. An emission nebula is formed due to the high energy UV radiation from the newly born stars which ionize the surrounding gas. This type of emission nebula is known as HII region. Together with its neighbor, it forms a famous pair called ‘The Heart and Soul Nebula’.
The Heart Nebula
Heart Nebula is located at around 7500 light years in the constellation Cassiopeia. It means we are currently looking at how it actually looked like 7500 years ago. This nebula was discovered by Sir William Herschel on November 3rd, 1787 when he pointed his telescope towards the Cassiopeia constellation.
At the center of this nebula, located is a open star cluster called Melotte 15, contains a few bright stars nearly 50 times the mass of our Sun and also a very few stars that have a mass lesser than the Sun. An open star cluster is a type of star cluster in which more than a thousand stars were formed from a giant molecular cloud of gas and dust. Melotte 15 star cluster is responsible for the red color of the nebula because the winds and radiation from the stars in the nebula ionizes the gas and excites the hydrogen into its excited state thus, releasing photons with a wavelength which is red in color. The brightest part of the Heart nebula is the NGC 896 which was the first part of IC 1805 discovered and thus was listed separately in the New General catalogue.
The Soul Nebula
The Soul Nebula is also an emission nebula located around 7500 light years in the constellation Cassiopeia. This nebula is also known as the Westerhout 5 nebula. Several small open clusters of stars are also located in the nebula that includes CR 34, CR 632, CR 634 and IC 1848. Soul Nebula is the eastern neighbor of the Heart Nebula and sometimes both of the nebulas are captured by the astrophotographers together thus both of them are collectively known as the Heart and Soul Nebula. Astronomers have also found two galaxies Maffei 1 & 2 near the Soul nebula. It was once thought that they belonged to the Local Group of galaxies, which our Milky Way is part of but later it was found that they belonged to a separate group called Maffei group or IC 342.