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Key to the .txt files
- A standard 3-letter abbreviation of the constellation
- Right Ascension
- Magnitude (catalogue data or estimate)
- Magnitude used for the drawing
- the FOV of the drawing
- NE Lim.mag
- The naked-eye limiting magnitude
- Background sky
- An estimate of the general brightness of the sky. 1 is best and 5 is worst:
- 1 = Almost black, Milky Way very bright and M13 easily visible NE
- 2 = Good but not perfect. MW bright but fainter parts difficult
- 3 = Average. Milky Way visible but not bright
- 4 = Poor. Milky Way barely visible.
- 5 = Very poor. MW not visible. Full Moon nights.
- An estimate of the steadiness of the air mass. 1 is best and 5 worst.
- The altitude of the object. (Degrees above the horizon)
- An estimate of the general visibility of the object. 1 is best and 5 faintest:
- 1 = A showpiece. Very bright and easy
- 2 = Bright, easy without averted vision.
- 3 = Moderately faint without averted vision but bright vith it
- 4 = Barely visible without averted vision
- 5 = Visible only with averted vision
- 5b or 6 is occasionally used for objects at the 'Three photon limit' ie. suspected ones.