Celestial coordinates, maps and magnitudes
Answers are for parents and teachers.
1
How many degrees is α = 9 h?
135
2
How many degrees is α = 12 h 40 min? (12 · 15 + 40 : 4)
190
3
What is the brightness ratio of two stars differing by 5 magnitudes?
100
4
For a magnitude difference of 10, what is the brightness ratio?
10000
5
Why are horizontal coordinates unsuitable for a catalogue? Write briefly.
They depend on the observer’s place and time and change constantly.