 |  |  | | | | |||||
 |
|  | | Magnitude and Luminosity
|
| | ||||
 |  |  | ||||||||
| | | | | | |||||
|  | | |  Star magnitude (a measure of brightness) is defined such that a 100-fold increase in luminosity equals a 5-point decrease in magnitude. Luminosity distance defines how apparent luminosity depends on distance, and for distant stars depends also on factors such as red-shift.
| | |||||
| | | | | | |||||
| | | | | | |||||
| | |  Fill in either the star absolute magnitude or the apparent magnitude. Also fill in the luminosity distance (equal to the actual distance for nearby stars), and the calc will provide the unknown absolute or apparent magnitude, as well as the luminosity. If you fill in absolute magnitude, then luminosity can be calculated without a need for the luminosity distance. The absolute magnitude of the sun is 4.83. | | ||||||
| | | | | | | | | ||
© Andy & Steve Shipway 2008