What is the brightest star with absolute magnitude in the 88 constellations of the whole day?

The area of Ophiuchus is more than 1300 square degrees, which is the largest of all constellations. Theoretically, it contains the most stars (if the universe is similar on a large scale), and the brightest star is more likely to be in Ophiuchus.

At present, it is estimated that the brightest quasar is in the constellation (I forget which one).

PS。 Does the landlord mean that the ancients used to determine the absolute magnitude of more than 6,000 stars used for drawing various constellations?

If there are, it's hard to say, because the bright stars we can see with the naked eye are basically superstars that are close to the earth or slightly farther away (such as Betelgeuse, Betelgeuse, Betelgeuse, Tianjin IV, Ma Fuyi, Antares, etc. ), hundreds to thousands of light years away from us.