Astronomical pictures from a backyard observatory
CCD Image Index.
Cookbook 245 or Meade DSI Pro II, permanently mounted 8" f/8 newtonian telescope;

Determination of rotation period for Asteroid (716)Berkeley

Plot of Data

Data (text) file can be found here - http://eoni.com/~garlitzj/716_Data.txt

17P Holmes, the "puff ball" comet
-- Oct 28-Nov 2
-- Central Detail

Here is a way to "image" an asteroid and measure it too.
On occation an asteroid will occult (eclipse) a star.
When that happens the star will"blink" out for the time it
takes the asteroid to move through its crossection that its
path takes with respect to the observer and the star.

By timing the length and start of this event, one can determine
something about the location and size of the asteroid.

If a number of observers record the event, the size of the asteroid
can be measured to very good accuracy, and its precise location can be determined.

Most occultation observers use video recorders to measure these events.
However there is a way to do this with a ccd camera. Just prior to the
predicted event time, one turns off the telescope tracking. This provides
a streak as the star image drifts across the camera field. When the
asteroid obsures the star, the drift streak is broken, thus providing a recording of the event.

Here is my record of an event (Asteriod 153 Hilda)
that was captured by a multitude of observers last Thursday night,
[UT 07:04 July 20, 2007].





Information about asteroid occultations can be found at Steve Preston's site:
http://www.asteroidoccultation.com/
For information on asteroid occultation timing techniques, equipment and general information on the International Occultation Timing Association go to: http://lunar-occultations.com/iota/iotandx.htm