Two-colour diagrams
Two-color diagrams
Photoelectric magnitude
Photovisual magnitude
Period determination
Pogson scale
Limiting magnitude
Variable star period change
Photographic magnitude
Magnitude
Visual magnitude
A measure of a star's observed brightness (opposed to absolute magnitude); symbol m. It depends on the star's intrinsic brightness, its distance from the observer, and the amount of interstellar absorption. The brightest star Sirius has an apparent magnitude of -1.46, while the weakest stars visible with the naked eye in the most favorable observation conditions have magnitudes of about +6.5. The stars of magnitudes less than +23 are measured by professional observatories, whereas those of magnitudes less than +30 by a telescope such as the Hubble Space Telescope.
Apparent magnitude