Figure 10-5 The Apparent Magnitude Scale Astronomers denote the apparent brightness of objects in the sky by their apparent magnitudes. The smallest rankings are for the brightest objects. (a) Stars near the constellation Orion, labeled with their names and apparent magnitudes, show a variety of apparent brightnesses. The dimmest stars have the largest apparent magnitude numbers. (b) Stars visible to the naked eye have magnitudes between m = −1.46 (Sirius) and about m = +6.0. However, the Hubble Space Telescope or a specially equipped, large Earth-based telescope can reveal stars and other objects fainter than magnitude m = +30.