ASTR 402 Observing project:

Due: END OF FINALS (because of Comet ISON)

Observe at least 6 solar system objects. Draw a sketch using the jpg or pdf observing form, being sure to note the location, telescope used, etc. Put a sketch of what you see in the eyepiece in the circular field. Try to make it accurate as to the relative size of the object compared to the field of view. Use a different page for each session. One of your objects can be the Sun (use safe techniques!)

We will be having several special "Comet ISON" observing sessions. One will be during finals week (overnight at George Observatory). Thus this year the due date will be later.

You may do your viewing at "Astronomy Day", George Observatory (Oct 12 this year), 3 - 10 pm. Excellent time to knock them all out! Doors open 3pm for talks but observing doesn't start till dark, obviously.

Limiting magnitude: The "limiting magnitude" is the magnitude of the dimmest star you can see with your naked eye. Use a finder chart or a sky program on your phone or iPad to check the sky. Note it can change during the evening!

Field of View: If the Moon is visible, it makes a great way to estimate the field of view, since it is a half-degree (30 arc minutes) across. But if the Moon isn't out, you can user Jupiter of Mars. Given Jupiter's or Mars' size in your field of view, you can estimate the field of view of the eyepiece by seeing how many Jupiters or Marses fit across the field of view.

Find out how far away Jupiter or Mars was the day you observed (use Stellarium). Use its physical size to get its angular diameter; from that you should be able to calculate the field of view. NOTE: once you calculate the field of view using one eyepiece/telescope combination, it stays the same for other objects using that eyepiece and telescope.

Magnification: Equals the focal length of the objective divided by the focal length of the eyepiece. The Focal Length of the observatory 16 inch telescope is 4 m; of the 11-inch Celestron is 2m; of the 8 inch Celestron, 1 m. Most of the time we will use the 31mm eyepiece for wide views and 12mm for higher magnification. The field of view is inversely proportional to the magnification.

There will be at least four evening sessions, but we get clouded out a lot, so be sure to come to the first possible session you can!

Or, you can go the "George Observatory" (in Brazos Bend State Park) any clear Saturday evening.

last revised: 9/20/2013