As an expert in astronomy, I can tell you that the concept of the "biggest" star can be a bit misleading because it depends on what you mean by "biggest." If you're referring to the most massive stars known, then the title often goes to stars that are in the class of "Wolf-Rayet" stars, which are extremely hot and luminous. However, if you're talking about the largest in terms of volume, then the current record holder is UY Scuti, a red supergiant star. It's important to note that these classifications can change as new observations are made and as our understanding of astrophysics evolves.

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The largest stars, in contrast, will be cool supergiants. Case in point, VY Canis Majoris is only 3,500 Kelvin, and a really big star would be even cooler. At 3,000 Kelvin, Humphreys estimates that cool supergiant would be as big as 2,600 times the size of the Sun.read more >>