The Greeks assigned what magnitude to the brightest star seen the night sky? 1

The Greeks attributed magnitude 1 to the brightest star seen in the night sky.

Explanation:

The Greeks created a system of magnitude based on the brightness of stars in the northern sky. It is not known for sure which astronomer was responsible for this, although many believe Hipparchus or Alexander Ptolemy is the creator.

These magnitude systems related the star's apparent brightness to its actual size. That way the brighter the star appeared in the night sky, the bigger its real size would be. For the brightest stars, magnitude 1 was associated.

On the modern magnitude scale, Sirius, the star with the brightest apparent magnitude, has been assigned a magnitude of - 1.5.