In the universe there is an enormous quantity of stars, which, between them, the most part of these last, are of a type named “red dwarfs”, which is the smallest star type, but also those that live during more time. Even so, there are also stars that have gigantic dimensions and that occupy a very big surface.
Stephenson 2-18, also known as Stephenson 2 DFK 1, is the biggest star in the universe known nowadays. Stephenson 2-18 is a red supergiant situated in the Scutum constellation. Beside that, it is also situated in the opened cumulus Stephenson 2, at approximately 6 000 parsecs (20 000 light years) of distance in relation to the Earth. Inside this star agglomeration there is a central aggroupment of 26 supergiants, which can be the most young and massive star agglomeration in the Milky Way.
Stephenson 2-18 isn’t only the biggest known star, but, additionally, it is also considered one of the stars of the red supergiant type with maybe the biggest luminosity, with an approximative luminosity of about 440 000 solar luminosities.
With an approximative radius that would correspond to 2 150 solar radium, this star has so big dimensions that, if we putted this star into the solar system, it would be capable of surrounding Saturn’s orbit, which corresponds to a diameter of 1940 to 2169 solar radium.
The previous biggest stars
Stephenson 2-18 is nowadays, as I said, the biggest star known, but before some other star were known, likewise very big, but they were still too small to compete against Stephenson 2-18. For example, the biggest star after Stephenson 2-18 is Westerlund 1-26, with about 2000 solar radium
Two more known stars, and that in their epoch were considered to be the biggest stars known are the star UY Scuti, and Canis Majoris, which if they were placed in the solar system, each of them would have a similar size to Jupiter’s orbit.