Can someone explain this diagram?
The text is in Dutch, free translation: "You are given a graph: a histogram of the 10 000 most apparent bright stars. Explain 1, 2 and 3."
The fact that the number of counted stars of types O and M is small due to
- O is bright but just very rare and,
- M is common but quite dim.
The puzzling bit in this diagram is the sudden dip from a local maximum F (why is there a maximum) to G (why is G a local minimum). The drop from K to M is explained above - that being that M class stars are just very dim (is this all there is to say here?).
It seems that if there wasn't a dip at 3, and the graph would just continue, that the local max at K can be explained as being there just because there is a dip at G. If there wasn't a dip it wouldn't be a maximum and it'd just look like a bell-curve.
So
- Why is there a dip at G?
- Why does it rise so smooth from O to F? Is it just because B - F are more common?
- Why is there a maximum at F?