Negative numbers indicate extreme brightness. We can see objects up to 6th magnitude without a telescope. Apparent magnitude is abbreviated m. This system of rating the brightness of celestial objects was developed by the Greek astronomer Hipparchus in 120 B.C. Absolute magnitude is a measure of the inherent brightness of a celestial object. The lower the number, the brighter the object.
Negative numbers indicate extreme brightness.
Antares is a M1.5Iab variable red supergiant star that is about 520 light-years from Earth and is about 230 times as big as the Sun . Arcturus is 34 light-years from Earth. It has an apparent magnitude of -0.04 and an absolute magnitude of 0.2. If Betelgeuse were at the center of our Solar System , it would extend beyond the orbit of Jupiter. It is 520 light-years from Earth.