Astro 121 Solar Obs erving Worksheet 3/30/05
Astronomy 121: Day Observing Worksheet
(due in Section or with Homeworks)
Note: Do not look directly at the Sun!!!
Name:_________________________
Signature of TA leading the Solar Observing:______________________
1. What is the date and time of your observations? What are the sky
conditions (e.g. clear, partly cloudy)?
2. Follow these instructions to determine the Right Ascension and
Declination of the Sun today. First, estimate the local sidereal time (or
read it off the clock in the dome) and write it down as the first part of
your answer. The local sidereal time is the Right Ascension of the
meridian, the great circle running north-south through the celestial poles
and the zenith. Second, find the hour angle of the Sun by reading it off
the telescope setting circles and write it down as the second part of your
answer. Either add or subtract the hour angle of the Sun from the local
sidereal time to get the Sun’s RA (remember that RA increases toward
the East) and write this down as the third part of your answer. Read the
declination off the telescope setting circle and write this down as the
fourth part of your answer. Congratulations!
