Sun Avoidance Information
To avoid excessive heating of the feed legs, the prime focus regions, and the cables of the prime focus, the SMT telescope will not be pointed to within 42 degrees of the sun, 15 degrees for the 12 Meter. The following table lists the apparent RA and Dec of the Sun on the first of each month (we have ignored the small year-to-year changes due to precession). Observers are encouraged to use this information to specify their proposal requests for observing time.
Verifying source distance from Sun using Astro:
Generating 'Astro' catalogs from ARO catalogs:
The Astro program can read a catalog of objects and can make a plot showing when the objects are up and whether or not they are currently too close to the sun. It will also state the range of dates for which the objects are too close to the sun. The catalog file (default type .sou) is in a different format than used for ARO catalogs (.cat files).
ARO .cat files can be easily converted to .sou files with:
where aro.cat is the ARO catalog file and astro_cat.sou is the resulting Astro format.
The astro_cat is then read into Astro with:
And a plot can be made with:
This command also prints out what dates are unsuitable for observing these objects, if any.
A similar plot for planets can be made with
Sorry, there's no way to do comets in Astro, other than to get their current RA and Dec and put them in a .cat (or .sou) file as if they were stationary objects.
Copyright Arizona Radio Observatory.