A protostar.
The magnitude of a star means how bright it is.
One very large red giant star is Betelgeuse, which is the bright-red shoulder of Orion.
This is called "Apparent Magnitude".
How large it is and how far away it is.
A star that explodes is called a supernova.
No; the "magnitude" is how bright the star is. It can either mean:* The apparent magnitude = how bright it seems to us, * The absolute magnitude = how bright the star really is (i.e., how bright it would seem at a standard distance).
A supergiant
The apparent magnitude.
The brightness of a star is called visual magnitude. The lower the visual magnitude is the brighter the star is.
venus
That's called the star's absolute magnitude.
That's the number called the star's "Absolute Magnitude".That is called the star's "absolute magnitude".