Observing basics
视星等
Apparent magnitude
Brightness as seen from Earth, not intrinsic output.
The Sun is −26.7, the full Moon −12.7.
Related terms
- Extinction — Atmosphere dimming starlight.
- Dark adaptation — Eyes adjusting to darkness over 20–40 minutes.
- Averted vision — Looking slightly off-target to use rod-rich retina.
- Red light — Reading charts under red light to keep dark adaptation.