Red Supergiants:

* Betelgeuse (Alpha Orionis): One of the brightest stars in the night sky, located in the constellation Orion. It's nearing the end of its life and is expected to explode as a supernova.

* Antares (Alpha Scorpii): Another bright star, this one in the constellation Scorpius. It's a red supergiant that's 15 times more massive than the Sun.

* Mu Cephei: A very large red supergiant, known for its reddish-orange hue. It's one of the largest known stars.

* VY Canis Majoris: A massive red supergiant, one of the largest known stars, with a diameter estimated to be around 1,800 times that of the Sun.

Blue Supergiants:

* Rigel (Beta Orionis): The bright blue star in Orion's knee. It's a blue supergiant with a mass 18 times greater than the Sun.

* Deneb (Alpha Cygni): The brightest star in the constellation Cygnus, it's a massive blue supergiant with a luminosity thousands of times greater than the Sun.

* Spica (Alpha Virginis): The brightest star in the constellation Virgo. It's a blue supergiant that's part of a binary star system.

Other Notable Supergiants:

* Polaris (Alpha Ursae Minoris): The North Star. It's actually a triple star system, with the primary star being a yellow supergiant.

* Eta Carinae: An extremely massive and unstable star in the constellation Carina. It's known for its violent outbursts and is expected to go supernova in the next few hundred years.

It's important to note that supergiant stars are very rare and have relatively short lifespans compared to other types of stars. Their massive size and brightness make them fascinating objects to study.