4.5" Orion SkyQuest

Object: Abell 21 / PK 205+14.1
Obs. place: Rajasuo, Hyvinkää, Finland (108 m / 354 ft)
Date: 26./27.3.2014
NE Lim.mag: 6.0 (zenith)
SQM-L: 20.20 (zenith)
Background sky: 4 (fair)
Seeing: 4 (fair)
Transparency: 5 (average)
Weather: -4.2°C, humidity ~80%, 1032 hPa, faint gusts of wind.

Altitude: 35°
Description:
Very faint, 8' crescent-shaped planetary nebula visible only with a Lumicon O-III filter. Slighly brighter at both ends. Best seen @ 76x (46').
Abell 21 with 4.5" Orion SkyQuest @ 101x (24')