I know this is rather short notice, but we are implementing a campaign make CCD observations of comet 9P/Tempel 1 on the weekend of July 8-9. There will be another campaign on the last weekend of July or the first weekend in August.
The goal of this campaign is to obtain scientifically useful observations over a period of about 48 hours. During this campaign, the morning sky will be dark since the moon is at first quarter. We need you to begin observations on the morning of July 8 (local time), then again during the morning of July 9. The comet is visible from the southern and northern hemispheres and has a predicted apparent visual magnitude of about 15 (last week, one of our observers reported the observed magnitude could be as faint as 17).
Observing procedures and a link to an ephemeris generator can be found at http://www.ss.astro.umd.edu/deepimpact/stsp/observing.html. Please contact me if you have any questions! In general, we need you to:
1) Make images of the comet using the following filters a) Photometric V and R or R and G filters from a photographic RGB set (you may try the B filter, but comets do not emit much in this band). If you use photographic R and G filters, you must include an infrared-cutoff filter. We will use V- and G-filtered images for photometry and R-filtered images for coma structure and dust activity studies. b) Clear (or no filter). We will use these images to monitor overall brightness changes over time and heliocentric distance. NOTE: Multiple, short exposures (1-3 minutes, with accurate tracking) allow us to do the most analysis. Single, long exposures, where a magnitude of 19.5 is reached, can be used for brightness analysis even if the comet trails a little. NOTE: Comet images need to contain a few stars so that we can callibrate your images. 2) Make 3-5 flat frames for each of the filters you observe with. 3) If you have a nitrogen-cooled CCD, make 5-10 bias frames and 3-5 dark frames using an exposure time of 1-2 minutes. If you have a thermoelectrically-cooled CCD (most commercial CCDs): If your CCD software performs automatic dark frame subtraction, turn this feature on and indicate this in your observing log. If your CCD software does not perform automatic dark frame subtraction, make 3-5 dark frames using the same exposure times used for the comet images. 4) Take images of at least 3 standard stars using each filter. A list of standard stars and instructions for choosing stars will be available by July 1 at: http://www.ss.astro.umd.edu/deepimpact/stsp/observing.html#sec9 5) Keep an observing log! Include the longitude and lattitude of your observatory in your log. Also, include weather conditions. For a sample, go to: http://www.ss.astro.umd.edu/deepimpact/stsp/observing.html#sec2 6) Format all images as FITS. 7) Transfer FIT images to Stef McLaughlin using an anonymous FTP process. Instructions are at the end of this email!Also, images taken from July 1 (new moon) through July 7 would be scientifically useful.