Figure 1. The Whirlpool Galaxy is a faint smudge inside the cross-hairs wthin the constellation Ursa Major (The "Big Dipper").The "speckle" pattern looks like noise, but it's really a field of faint stars captured by a long exposure (as shown in the next figure, which is a blow-up of a small region centered on the Whirlpool Galaxy). 9th magnitude stars are barely visible. The image is 40 degrees wide. North is at the top. [2001.03.29, Minolta 35-mm camera,strapped to Meade ETX125EC for guiding, 50mm f/1.7, 2.5-minute exposure, Kodak Elite Chrome ISO 400, resolution-spoiled for web page display].
Figure 2. Two-times enlargement of above image (less resolution degradation for web page display), showing Whirlpool Galaxy in crosshairs. The faintest stars are magnitude 9.2.
Figure 3. Two-times expansion in scale, but using different picture. The bright star in the upper left is the "end of the handle" star. The dotted lines trace a path to the Whilpool Galaxy, located above the arrow. Notice that M51 appears to be a double smudge, having brightnesses in the ratio of about 3 to 1 (their magnitudes are 8.4 and 9.6). Notice the different-colored stars. [2001.03.23, Mamiya 645 "medium format" camera, 45mm f/2.8 lens stopped to f/5.6, mounted to Meade LX-200 10-inch Schmidt-Cassegrain telescope for tracking and occasional hand-guiding adjustments,30-minute exposure, Kodak Portra 400 NC film.]
Figure 4. Twice as "close" using a telephoto lens on a 35-mm camera. In this (resolution reduced) version of the image the faintest stars are magnitude 11.0 (in the original image, magnitude 11.6 stars can be seen). The previous image may "seem" to show fainter objects because M51 is "brighter" but this apparent discrepancy is accounted for by the fact that this image has greater resolution (showing star images as 26 "arc Gaussians instead of 160 "arc in the previous image). [Minolta 35mm camera, 285mm f/5.8 lens, mounted to LX-200 10-inch for tracking, 8-minute exposure, Kodak Elite Chrome ISO 400 pushed to ISO 800].
Figure 5. Twice as close, showing spiral arm structure of the main Whirlpool Galaxy component. The faintest stars in this image are magnitude 13.3. [2001.04.23/24, using Nikon F3 with 400 mm f/5.6 telephoto lens, attached to Meade LX200 10-inch SCT for tracking and hand guiding corrections, Fujicolor Superia 400 film, pushed to ISO 800, average of four 10-minute exposures.]
Figure 6. Zoom factor 1.8. This black and white image shows fainter stars and whisps of the galaxy. [SBIG ST-8E CCD, 400 mm EFL telephoto lens, f/9, avg of six 60-second exposures, 2002.05.15 UT, Figueroa Mountain, 4528 feet ASL]
Figure 7. Only slightly closer, but showing more detail. The southern component is now clearly seen as the one with spiral arms, which the other component lacks. Stars of magnitude 14.7 are visible in this image. [2001.04.22/23, using Meade LX200 10-inch SCT, f/6.9, Nikon F3 camera body at prime focus, 10.1-minute exposure with Fujicolor Superia 400 film.]
Figure 8. Zooming in by a factor of 2.5 shows more spiral arm detail. [2002.03.18, using Meade LX200 10-inch, f/2.0 (i.e., using 2.4x "focal ratio reducer"). Image is result of adding two 3-minute exposures (after correcting for dark frames) w/ Meade Pictor 416XTE CCD imager.]
Figure 9. Small zoom factor, but a significant improvemet in "resolution." The star widths (for those not "saturated") are 3 "arc. At least two distant galaxies are barely discernible in the upper-left region. [Meade LX-200 10-inch SCT, f/6.3, SBIG ST-8E CCD, unfiltered, total exposure 27 minutes, 2002.05.17 UT, Santa Barbara, CA residence]
Figure 10. This twice larger version has greater resolution because it was taken at the prime focus (without a focal reducer). The image has dimensions 14.7 x 9.7 'arc. I estimate that stars as faint as magnitude 17 are visible in this image. [2002.03.02/03, Meade LX-200, 10-inch, Meade 416XTE CCD imager, constructed from 11 3-minute exposures using RGB filters, total 33 minutes of exposure time.]
[I'm working on a color version with the same scale as the image above.]
__________________ THE FOLLOWING PICTURES WERE TAKEN BY OTHERS ________________________
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For comparison, here's another Jack Newton (advanced amateur) CCD image of M51. He used a 25-inch f/5 telescope with a Pictor 1616XT CCD imager, exposing for 10 minutes. From Meade's General Catalog.
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NASA Hubble Space Telescope and Kitt Peak National Observatory picture.
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This site opened: August 26, 1998. Last Update: May 17, 2002