Quick Read
Betelgeuse is an enormous reddish star visible to the unaided eye in Orion.
Learn More
A diameter of about 7.1 astronomical units is representative. Its extended atmosphere has no sharp, unchanging edge.
In Depth
Radius estimates depend on distance, wavelength, and the photospheric definition, so the displayed value is model-dependent.
Scale measurement
7.086 AU · diameter
Quick facts
- It is a red supergiant.
- It lies in Orion.
- It is a semiregular variable star.