UY Scuti is a red supergiant, and is one of the largest known stars by diameter behind VV Cephei A and VY Canis Majoris, but Westerlund 1-26 may be larger than both of them at 2,544 solar radii (3,543,242,496 km), but is likely smaller at 1,530 solar radii (2,128,942,520 km). 

Properties Edit

Though it was discovered long ago, we only recently discovered it's tremendous size! In 2012, it, along with KW Sagittarii and AH Scorpii were determined to be at least 1,000 times wider than the Sun. We eventually found out that it was 1,708 ± 192 (2,378,875,072 ± 267,414,528 km) times wider than the Sun.

Diameter 2,646,289,600 km
Temperature 3,092 °C
Mass 10x Sun
Spectral Type M4 Ia
Apparent Magnitude +18.46
Gravity 0.8913 m/s2
Constellation Scutum