I love everything about space and its vastness. UY Scuti, a special star, has caught my eye. It’s a red hypergiant star much bigger than our Sun. UY Scuti is far away, more than 6,000 light years, in the Scutum constellation. Its size is enormous, with a radius over 1,700 times that of our Sun. Placing UY Scuti in our solar system would stretch its outer layers to the orbit of Jupiter, eating up all our planets.
Think about this – you could put 5 billion suns inside UY Scuti. Our familiar Sun is just a tiny point next to this massive star. Such size and scale show how grand and varied our universe is.

Redefining the Scale of Celestial Bodies
Our Sun, known for its size, is 1.4 million km across. It could hold about 1.3 million Earths inside. Yet, UY Scuti is a different story. It’s so huge that it could fit 1,708 Suns inside it. Imagine, if UY Scuti were our Sun, it would reach beyond Jupiter.
Astronomical Units: Measuring Stellar Radii
Scientists use astronomical units (AU) to talk about stars like UY Scuti. One AU is the distance from Earth to the Sun, about 150 million km. The radius of UY Scuti is 8 AU, which tells us it’s truly gigantic.
“UY Scuti is so massive that if it replaced the Sun in our solar system, its outer edge would extend past the orbit of Jupiter.”
Star | Diameter | Radius | Comparison to Sun |
---|---|---|---|
Sun | 1.4 million km | 695,700 km | 1x |
UY Scuti | 2.4 billion km | 1.2 billion km | 1,708x |
VY Canis Majoris | 2.84 billion km | 1.42 billion km | 2,040x |
WOH G64 | 3.08 billion km | 1.54 billion km | 2,211x |
