Arecibo Observatory


Calculating Observing Parameters for the ALFALFA January 2010 observing

Background Reading

Review your understanding of the equatorial coordinate system (right ascension and declination). See first bullet in Things to Know for help.
Review the memo on ALFA beam rotation and ALFALFA Observing Mode


Calculations

Target drifts for the ALFALFA workshop include +201906 and +194954; the central beam (designated Beam "0") is the one that is set to the declination listed. We will observe the drifts from 0145 -0715, i.e., 1:45 to 7:15 am Arecibo time, on 11 and 12 Jan, 2010. Visit the summary of upcoming observing page to find our schedule.

  1. For the +201906 drift, list the resultant seven declinations covered by the seven beams, in order, from south to north for the first drift. What is the resultant declination range? Visit this page for help.
  2. What is the range in local sidereal time (LST)? This is approximately the right ascension range that we will cover. (Hint: look again at the summary of upcoming observing page.)
  3. What is the zenith angle of this drift as observed with ALFA beam 0?
  4. At what azimuth will we orient the azimuth arm so that ALFA can observe this declination strip?
  5. Repeat exercises 1-4 for the second drift.
  6. Go back and search for targets!



Last modified: Mon Oct 5 12:02:36 EDT 2009 by becky