Observing basics
视宁度尺度
Pickering scale
A 1–10 scale for how steady a star looks.
Above 8 you can push high power on planets.
Related terms
- Lunar eclipse — The Moon passing into Earth's shadow.
- Zodiacal light — Sunlight scattered by interplanetary dust, a faint cone.
- Air mass — Relative air path; 1 at zenith.
- Extinction — Atmosphere dimming starlight.