1. The problem statement, all variables and given/known data At midnight (local time) on Dec 21st 2015, the Local Sidereal Time at Palomar Observatory, California, was 6h 27m. Palomar Observatory has latitude 33◦ 210 2100 N, and longitude 116deg 51arcmin 60arcsecW. a) What was the approximate Local Hour Angle of the Sun at 23:00 local time? b) At what local time was the Sun on the meridian at Palomar Observatory? c) How many hours before the time determined in part b) was the Sun on the meridian at La Palma Observatory in the Canary Islands (located at latitude 28◦ 450 2500 N, and longitude 17◦ 530 3300 W)? 2. Relevant equations I know that the calculation for hour angle is Local Sidereal time - Right ascension of the star, the star in this case is the sun and the date given (Dec 21st) equates to a right ascension being 18h as it is the winter solstice. Longitude can be converted to hours by doing 116 + (51/60) + (60/3600) = 116.87 then (116.87/360) x24 3. The attempt at a solution I first tried just to plug in the values of right ascension being the winter solstice so just tried 6h 27m - 18h 0m to get an hour angle of 11h 33m for part a. I also attempted in a second alternative method to convert the longitude values to hours and use this value for the right ascension and received a value for the hour angle to be 1h 20 minutes. I am not sure what the 23:00 time has to do with the question and which method gives a closer answer. Any help would be greatly appreciated in finding the correct values with an explanation why. Thank you. Really sorry, used the wrong forum and not sure how to delete thread.