Observations of CHIRON by Denis Bergeron, Val-des-bois, Quebec, Canada (E-MAIL: bergeron@achilles.net) Night of March 28th to March 29th, 1995 Hello dear friend astronomer, This is my fourth report of observation about CHIRON My astronomical equipment is a Meade SCT LX-200 10'' F10 telescope with a telecompressor lens to reduce my f/ratio to about F6.0 and a SBIG ST-6 CCD camera at prime focus. I also use a CCD SBIG ST-4 at prime focus of my piggyback SCT telescope 4'' F10 to autoguide my Meade. All CCD pictures were exposed 5 minutes each. I had taken 28 exposures during this session. My first exposure was taken on March 28th 1995 at 22h34 EST and my last picture on March 29th at 02h00 EST. No filter was used. During this observation session, I have taken 5 dark frames of 5 minutes. In the end, I took a flat field image. The following days, I averaged my dark frames and I calibrated (dark subtract and FF corrected) all my pictures. With my software, I add up 28 images centered on stars to create a picture showing CHIRON'S MOVEMENT between stars (see CHIRON-1.FIT) and another picture centered on CHIRON to show CHIRON alone (see CHIRON-2.FIT). I haven't detected any evidence of COMA around CHIRON. I include images in FITS and TIFF . The pictures in FITS format are the result of the addition of my best images (averaged). Use these images if you wish analyse them. The TIFF pictures are the same images but processed with my image processing software. I include an ANIMATION of CHIRON in the sky (CHIRON.FLI). To see the blink effect, try a software such as AUTODESK ANIMATION (AAPLAY) capable to read FLI files. Remark the presence of an asteroid in upper part of the image above Chiron (near the center). I use Chiron's ephemerides supplied by CPC. They are very precise. If you wish to find Chiron easily, use software with the GUIDE STAR CATALOG such MEGASTAR, THE SKY or others. Plot the position of Chiron on the chart and try to identify the area where Chiron is. Be patient! Don't expose your images more than 10 minutes. I detect a slight shift in my images. It's best to take many 5mn images and add them up to increase the S/N. Be careful to don't saturate the pixels. If you have images of Chiron, please prepare the best ones and send a copy of them to CPC. I'm very interested to look at them. See my others reports Bye