M51, The Whirlpool, with a 4 inch refractor

M51, The Whirlpool Galaxy and companion, (NGC 5194 and 5195)
Sketch and Details by Rony De Laet

M51, the Whirlpool Galaxy, offers a pleasing sight in small telescopes. The Whirlpool (NGC 5194) and its small companion, NGC 5195, are an interesting duo. Both show a stellar nucleus and a condensed core. The challenge comes with the observation of the halo of both galaxies. Small scopes offer little contrast. Therefore the eye needs time to discern any features within these halos. Averted vision is mandatory to see where the ‘bridge’ between the two objects is located. The bridge is not visible, but M51’s halo shows an extension on its E side towards NGC 5194. Both objects are 29 million l-y away. NGC 5195 is about as luminous as our own Milky Way, while the Whirlpool is even 3 times brighter!
M51 is located at 3,5° SE of Eta Ursae Majoris.

Site : Bekkevoort, Belgium ( 51° N )
Date : March 23, 2009
Time : around 22.15 UT
Scope : Skywatcher 102/500mm achromatic refractor
Eyepiece : Baader Hyperion Zoom at 8mm
Magnifiction : 63x
FOV: 65’
Filter : none
Seeing : 3/5
Transp. : 2/5
Sky brightness : 19.70 magnitudes per square arc second near zenith (SQM reading).
Nelm: 5.3
Sketch Orientation: N up, W right.
Digital sketch made with Corel Paint Shop Pro X2, based on a raw pencil sketch.