The biggest star, in terms of volume (size), is UY Scuti.
UY Scuti is a red hypergiant star located in the constellation Scutum. While the mass of a star also contributes to its overall size and gravitational influence, the term "biggest star" generally refers to its physical diameter or volume. UY Scuti is estimated to have a radius of approximately 1,700 times that of the Sun. This means that if UY Scuti were placed at the center of our solar system, its surface would extend beyond the orbit of Jupiter.
It's important to note that the definition of "biggest" can sometimes be ambiguous. While UY Scuti holds the title for largest diameter, R136a1 is considered the most massive star. R136a1, located in the Large Magellanic Cloud, has a mass estimated to be between 170 and 230 times the mass of our Sun.
Here's a comparison:
| Feature | UY Scuti | R136a1 |
|---|---|---|
| Type | Red Hypergiant | Wolf-Rayet star |
| "Biggest" By | Diameter/Volume | Mass |
| Estimated Size | ~1,700 Solar Radii | Significantly smaller diameter than UY Scuti |
| Estimated Mass | Uncertain, likely a few tens of solar masses | 170-230 Solar Masses |
| Location | Constellation Scutum | Large Magellanic Cloud |
Therefore, to reiterate: when people ask about the "biggest star," they usually mean the star with the largest diameter, which is UY Scuti. Massive stars like R136a1, while extremely important and influential, are a separate category in terms of stellar characteristics.
