What are sky maps? How are they made?
1 Answer
Mapping the sky every night, over a year, the narrow peripheral changes are observable. Overall, joining of these maps, with due care to avoid marginal repetitions,the sky map is obtained.
Explanation:
Sky maps usually show stars in the space around, with other space
bodies that reveal their presence, by reflecting light from their
parent stars. In brief, they reveal which is which in the star world.
Making of sky map:
By conical angular rotation of the viewing device, the map for the
night sky could be made by the cut-paste method.
The pre-telescope mapping divided the
12 zodiacs. Each covered 2-D
(3-D
Then 12 became 13, and now, the division designates 88
constellations..
Broader division is into
North Circumpolar skies,
Eastern skies
Western skies
South Circumpolar skies.
For this sky atlas see
pp 309-338, Deep Sky Objects (2005), David H. Levy