Observation Log - March 24, 2000

Observation Log - March 24, 2000 - Tinton Falls, NJ

M27, the Dumbbell Nebula in Vulpecula, a planetary nebula, magnitude 7.6, dimensions 8'.0 x 4'.7, distance is 815 light years. Images were taken using the f/6.3 focal reducer, for an effective f/ratio of f/4 (as were all images acquired tonight.) This is a composite of 4 images with a total integration time of 12 minutes.Images were processed with dark frame removal, flat frame, median filter, then compositing, Digital Development with MaxIm CCD (FFT low-pass medium) and finally a contrast stretch. Images were taken between 4:46 a.m. and 4:57 a.m. the morning of March 24, 2000. Tonight's images were the first that I have processing with a flat field image, and it certainly helps! The MX516 was prone to bright edges on the bottom and right edges of the frame, and some streaks elsewhere. The flats seem to take care of the problems easily. Flats were taken on the morning twilight sky, with exposures of about 1/100 to 8/100ths of a second. Sorry I didn't have time to take images through the color filters. M27 didn't rise above my tree line until just before twilight, and I just couldn't squeeze in the color frames. I'll try again in a few weeks when the timing is better.

NGC2775, a spiral galaxy in Cancer, magnitude 10.3, dimensions 4'.5 x 3'.5. This is a composite of 12 images with a total integration time of 38 minutes. Images were processed with dark frame removal, flat frame, median filter, then compositing, gamma adjust (.8), and finally a contrast stretch. Images were taken between 8:43 p.m. and 9:27 p.m. the evening of March 23, 2000.

NGC2903, a spiral galaxy in Leo, magnitude 8.9, diam 12'.6. This is a composite of 11 images with a total integration time of 34 minutes. Images were processed with dark frame removal, flat frame, median filter, then compositing, gamma adjust (.8), and finally a contrast stretch. Images were taken between 9:51 p.m. and 11:28 p.m. the evening of March 23, 2000. Here is a lower-contrast version of the same image that shows more detail near the core. Here is yet another version of this image (processed 4/3/00) that uses the MaxIm Digital Development filter (FFT log-pass, hard) to bring out best detail in this galaxy.

M58, a barred spiral galaxy in Virgo, magnitude 9.8, dimensions 5'.4 x 4'.4, distance 55 million light years. This is a composite of 14 images with a total integration time of 42 minutes. Images were processed with dark frame removal, flat frame, median filter, then compositing, gamma adjust (.8), and finally a contrast stretch. Images were taken between 11:40 p.m. and 2:06 a.m.

M61, the Swelling Spiral, a spiral galaxy in Virgo, magnitude 9.6, dimensions 6'.5 x 5'.8, distance 55 million light years. This is a composite of 9 images with a total integration time of 27 minutes. Images were processed with dark frame removal, flat frame, median filter, then compositing and finally a contrast stretch. Images were taken between 1:40 p.m. and 2:40 a.m. (Images of M58 and M61 were intermingled after a refocus.) BTW, the three stars on the western edge (right) are approx. magnitude 14.0, 14.5 and 15.0, from south (bottom) to north.

M92, a globular cluster in Hercules, magnitude 6.5, diameter 14', distance 25,400 light years. This is an LRGB composite with 12 white images in the L channel for a total integration of 34 minutes, and 4 images in each color channel for a total of 12 minutes per color. Each channel was processed separately prior to color combination. Images were processed with dark frame removal, flat frame, median filter, then compositing by channel. Then the four channels were color combined, color weighted, saturation adjusted, color blended with an FFT low-pass filter, then processed with the MaxIm CCD Digital Development (kernel FFT low-pass) and finally a contrast stretch. Images were taken between 2:58 p.m. and 4:32 a.m.