Why can't you say that one constellation is brighter than another constellation?

I dunno, maybe get the magnitude of their main stars, then average it?|||I guess you could say it (Orion is among the brightest, Sagitta is one of the faintest) if you were talking about the main stars only.


But a constellation is not only those bright stars from the classical shapes of people, animals, other objects. A constellation is defined as an area in the sky which is defined with boundaries by the IAU. You could lump the total area of the constellation for brightness, as well as the bright stars.


If you did that, then Sagittarius or Scorpio or some other constellation with star clouds of the center of the Milky Way galaxy might be brighter overall than Orion even.|||One might not still be there (light takes a long time to reach Earth from different stars), or it might be much farther away then the other one to provide a couple of examples.|||The brightness again will depend on the distance between that star and us. For example we see moon as the brightest nightly body it is not the brightest object in our solar system.|||Distances. You can't tell if they're equidistant or if one is closer than the other. If one is closer, then it will be brighter. Also, one might be bigger than the other, the distances and size are a big factor.