Well, first thanks for your answers. The thing is, I calculate for example a sunrise on MSL with the depression and the declination of the sun on the day I want. When I use those graphs I get for example six hours and 4 minutes. Then I take the meridian passage of the sun in LMT and calculate the sunrise and sunset. Allright. Then I saw a question showing a picture like here
http://www.ap.stmarys.ca/~ishort/Astro/fig17l.jpg
and the checkers ask for hourangles. They
put pathes of stars or the sun like in the link into the painting and ask for the hour angle of such a path. The thing is is there an hourangle of 16 hours?allright you say yes. so does the expression hourangle mean the whole time the star is visible to me?so a circumpolar star would have an hour angle of 24 hours?
Thanks guys!
OD