Observing basics
近合
Appulse
The moment two bodies look closest.
Appulses often sit within a few degrees — good for photos.
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.