Intuitively, observing faint objects with low surface brightness against a bright sky, will be difficult. In order to achieve some kind of metric; amateur astronomers frequently quote sky brightness in terms of magnitude per square arc-second (mpsas). A very good night sky will have a brightness of 21.8 mpsas or greater while inner-cities are subjected to 15 mpsas rendering all but the brightest stars invisible.
Monthly Notes of the Astronomical Society of South Africa
- Pub Date:
- October 2017