The Tarantula Nebula, also known as 30 Doradus, is the largest star formation region known in our Local Group. It is an HII region, ie an ionized hydrogen nebula due to the ultraviolet radiation of the young and violent stars that are forming inside it.
The Tarantula Nebula is located within the Great Magellanic Cloud, one of the Milky Way‘s satellite galaxies, and is therefore only visible south of the Tropic of Cancer.
This nebula is very luminous, it has an apparent magnitude of +8, is “only” 160,000 light years from Earth and is about 1,000 light years wide. Do you think that, if it were the same distance as the Orion Nebula, the Tarantula Nebula would be about 60 times larger than the full Moon!
Inside the Tarantula Nebula there is a cluster of young stars classified as NGC 2070, which also includes a very compact area rich in stars, known as R136, which contributes most of the ionization of hydrogen in the nebula. The stars that make up the cluster are of class O3, blue supergiants. In total, the cluster has a mass of 450,000 solar masses and astronomers think that it will become a globular cluster in the future.
Another stellar cluster contained within the Tarantula Nebula is Hodge 301. It is older and the most massive stars in the cluster have already exploded as supernovae.
In general, this nebula is very valuable to astronomers and also hides some mysteries. For example, even if the theories on stellar evolution state that there can not be stars with a mass of more than 150 solar masses, at least four stars are present within the Tarantula Nebula with mass above this threshold, and even one of being has a mass of 300 solar masses.
Inside the Tarantula Nebula, on February 23, 1987, a supernova was observed for the first time, later cataloged as 1987A. For modern astronomy it was the first opportunity to observe with great detail the evolution of the supernova step by step and provided invaluable data to improve the theories on the final stages of the life of the stars.
A photo of the remains of the 1987A supernova taken from the Hubble Space Telescope.