You're likely thinking of the Orion's Belt, a prominent asterism (a recognizable pattern of stars) in the constellation Orion.

The three main stars in Orion's Belt are:

* Alnitak (Zeta Orionis) - The easternmost star

* Alnilam (Epsilon Orionis) - The middle star, the brightest of the three

* Mintaka (Delta Orionis) - The westernmost star

These stars are all hot, blue supergiants and are quite young, only a few million years old. They are also incredibly massive, making them very luminous and short-lived.

Let me know if you have any other questions about Orion's Belt or other constellations!