Expert: James Gort - 1/4/2009

Question
can you tell me how to first convert an example: 0hours 8min. 23.2 seconds to degrees for right ascension.
then how to convert example: +29degrees 5' 26" to degrees in a stars declination?

Answer
Hello Josh,

The easiest way is to set up ratios.  For example, there are 60 seconds in a minute and 60 minutes in an hour.  So 23.2 seconds is 23.2 / 60 = .39 min.  Then 8.39 min / 60 = 0.1398 hours (the 4 decimal places may not be justified here!).  Now, there are 24 hours in 360 degrees.  So 360 / 24 = x / 0.1398.  Solve for x = 2.0967 degrees.

For declination, it's even easier.  26" / 60" = 0.43'.  Then, 5.43' / 60' = 0.0906 degrees.  The answer in degrees is 29.0906.

Hope that helps.

Prof. James Gort