| 1 | Specifically, luminosity is proportional to radius squared. | |
| 2 | Stars are also classified by their luminosity under the Morgan-Keenan system. | |
| 3 | Astronomers describe star brightness in terms of magnitude and luminosity. | |
| 4 | Specifically, the luminosity of a star is proportional to temperature to the fourth power. | |
| 5 | There will be photometric and spectroscopic evidence for forests and savannahs. |