Spiral Galaxy (NGC 5194), type Sc, in Canes Venatici.

RA 13:29.9 (h:m); Declination +47:12 (deg:m); Distance 37 million light years
Visual Brightness 8.4 (mag); Apparent Dimension 11x7 (arc min)

The famous Whirlpool galaxy M51 was one of Charles Messier's original discoveries: He discovered it on October 13, 1773, when observing a comet, and described it as a "very faint nebula, without stars" which is difficult to see. Its companion, NGC 5195, was discovered in 1781 by his friend, Pierre Méchain.

For the amateur, M51 is easy and a showpiece if the sky is dark, but is quite sensitive for light pollution which easily makes it fade in the background. Under very good conditions, even suggestions of its spiral arms can be glanced with telescopes starting from 4-inch. Low magnification is best for viewing this pair.

Source and more: SEDS


April 24, 2009 20:05 - 22:19 UT.
Imaging: William Optics Zenithstar 80 ED II APO, f/6.8 [focal length 545 mm], Astronomik LRGB filters; ATK16IC camera.
Exposures: Luminosity 1x180s + 3x300s + 5x600s [1x1]; RGB 5x180s [2x2]; all unguided.

March 26, 2007 20:39 - 21:30 UT.
Imaging: William Optics Zenithstar 80 ED II APO, f/6.8 [focal length 545 mm] with 10 cm extender, Astronomik L-filter; ATK16IC b/w camera, K3CCDTools.
Exposures: Luminosity 11x300 seconds; autoguided.

April 4, 2006 21:59 - 22:41 UT and May 2, 2006 21:32 - 22:43 UT.
Combination of the colour and black-and-white images of the above days.
I used Astrowave to determine the scale and angle between the two images and layered them in Photoshop whereby the b/w image has been used as luminosity layer.
On the upper left hand side Galaxy IC4278 is just visible.

May 2, 2006 21:32 - 22:43 UT.
Imaged with LX200 10-inch f/10 telescope with 0.33 Focal Reducer operating at f/4.06 [focal length 1015mm], Vesta Pro-SC3a B/W RAW camera, Baader Infra Red Blocking Filter.
104 autoguided exposures of 30 seconds.

April 4, 2006 21:59 - 22:41 UT.
Imaged with LX200 10-inch f/10 telescope with 0.33 Focal Reducer operating at f/4.06 [focal length 1015mm], Vesta Pro-SC3a colour camera, Baader Infra Red Blocking Filter.
15 autoguided exposures of 80 seconds.

April 11, 2005 22:52 - 23:04 UT.
Imaging: TAL-2M 6-inch f/8 focal reducer operating at f/4.6 [focal length 690mm], Vesta SC3a b/w RAW webcam, Baader Infra Red Blocking Filter, because of tracking problems only 5 unguided exposures of 30 seconds.


April 19, 2004 22:43 - 22:45 UT. Imaged with TAL-2M 6-inch f/8, with focal reducer operating at f/4.6, Baader Infra Red blocking filter, Camera: Vesta Pro SC3a b/w RAW
Because I had problems with the tracking of my mount I captured only 5 exposures of 22 seconds, unguided.








April 19, 2004 22:43 - 22:45 UT.
I artificially colorized the black and white image in Photoshop:
First Image - Mode - RGB, followed by Image - Adjust - Variations and the I fine tuned the Saturation: Image - Adjust - Hue/Saturation.


April 15, 2004 23:29 - 23:42 UT.
This time I used my focal reducer.
The upper image is processed in the usual way, the lower one in YRGB fashion.
It is a pity that I omitted to switch the AMP OFF ....

I also processed with K3CCDTools 2, with Y-filter.
Here is the comparison of all three methods.


April 14, 2004 23:33 - 23:40 UT.
My first attempt to image this nice pair.