What are the five brightest stars on the constellation orion, and their greek symbols?

Answer 1

We were asked the five brightest stars not the stars whose symbols are the first five letters of the Greek alphabet.

So there are two mistakes in the first answer.

(1) β Orionis is brighter than α Orionis.

(2) δ Orionis is not in the top 5, γ Orionis is 3rd, ε Orionis is 4th and both ζ Orionis (5th) and κ Orionis (6th) are brighter than δ Orionis (7th).

IN DESCENDING ORDER OF BRIGHTNESS

Rigel (β Orionis) magnitude 0.18 773 light years away 6th brightest star in the sky, triple star system

Betelgeuse (α Orionis) magnitude 0.45 (variable) 427 light years away 9th brightest star in the sky,

Bellatrix (γ Orionis) magnitude 1.64 243 light years away

Alnilam (ε Orionis) magnitude 1.69 1342 light years away

Alnitak (ζ Orionis A) magnitude 1.74 817 light years away

Saiph (κ Orionis) magnitude 2.07 721 light years away

Mintaka (δ Orionis A) magnitude 2.25 916 light years away

Whilst a large majority of the 88 Alpha stars are the brightest in their constellations., there are some that are not. Another notable exception is Thuban (Alpha Draconis) which got the alpha designation because it was the Pole Star in ancient times (and will be again) despite being only the seventh brightest star in the constellation.

And α Piscium A is only the 3rd brightest star in Pisces.

So you cannot assume that alphabetical order is necessarily the same as the order of relative brightness

Answer 2

Betelgeuse = Alpha Orionis
Rigel = Beta Orionis
Bellatrix = Gamma Orionis
Mintaka = Delta Orionis
Alnilam = Epsilon Orionis