Betelgeuse is a very bright star, but it is not one of the 20 brightest stars in the sky as seen from Earth.

Here's why:

* Variable Brightness: Betelgeuse is a red supergiant, and its brightness fluctuates significantly. It is currently experiencing a period of dimming, making it less bright than it normally is.

* Distance: While Betelgeuse is intrinsically very bright, it is relatively far away from Earth (around 640 light-years). This distance diminishes its apparent brightness as seen from our planet.

While it's not in the top 20, Betelgeuse is still a fascinating and notable star. It is one of the brightest stars in the constellation Orion and easily visible to the naked eye.