Question

Which star is brighter: Orange-colored Pollux at an apparent magnitude of +1.1 or Red-colored Aldebaran at an apparent magnitude of +0.9 or Blue-colored Deneb at an apparent magnitude of +1.3 ?

Answer 1

Aldebaran is the brightest star out of the three mentioned because it has the lowest magnitude number of +0.9, indicating higher apparent brightness compared to Pollux and Deneb.

Step-by-step explanation:

The star with the brighter apparent magnitude between orange-colored Pollux (magnitude +1.1), red-colored Aldebaran (magnitude +0.9), and blue-colored Deneb (magnitude +1.3) is Aldebaran, having an apparent magnitude of +0.9. Remember that in the system of stellar magnitudes, a lower number indicates a brighter star. This counterintuitive system stems from historic observations by Hipparchus, who categorized the brightness of stars into six magnitudes, where the brightest stars were first-magnitude and the faintest visible stars were sixth magnitude. In contemporary terms, a difference of one magnitude is roughly equivalent to a change in brightness by a factor of 2.5. Therefore, since Aldebaran has the lowest magnitude number, it shines the brightest in the sky out of the three mentioned.