M51 NGC 5194 Galaxy ” Whirlpool Galaxy “

M51 NGC 5194 Galaxy
Whirlpool Galaxy M51 NGC 5194

Whirlpool Galaxy M51 NGC 5194

Telescope / Lens TEC 140mm f/7
Mount Type Astrophysics 1200
 Filters Astrodon LRGB
 Film  CCD
 Exposure 185 minutes (3 hours 5 min); LRGB (L=125,RGB=60) 5 min. exposures
 Processing CCDSoft, CCDStack, AIP, Photoshop CS2
 Date  04/20/2009
 Location North Eugene, Oregon (backyard)

Galaxy M51 NGC 5195 “Whirlpool Galaxy”
The Whirlpool Galaxy M51, is located within the constellation Canes Venatici (Hunting Dogs), just down 3.5° from the last star of the handle of the Big Dipper (URSA Major).

M51 lies 23 million light years from earth and is viewed by amateurs and professionals alike. Several background galaxies are also visible in the image. The Whirlpool Galaxy M51 (14.2 x 9.5 arc minutes) is interacting with it’s companion Galaxy NGC5195 (8.9 x 7.4 arc minutes). Both galaxies have a magnitude of 8.35 & 9.49 respectfully and are not visible to the unaided eye. The Whirlpool Galaxy is approximately 60,000 light year across. They do show up in good quality binoculars.

Charles Messier discovered M51 on October 13,1773. William Parsons, in 1845, using a 72″ reflecting telescope in Ireland, discovered the Whirlpool Galaxy had a spiral structure.  It was considered a nebula until Edwin Hubble established that these so called nebula were really separate and distinct galaxies by observing Cepheid variables in the early to mid-twentieth century.

Today a good 150mm (6″) telescope can reveal the spiral structure of M51 the Whirlpool Galaxy. Good quality binoculars will show the Whirlpool Galaxy M51a a fussy spot.


The edge-on galaxy lower right is IC 4263 (UGC8470), magnitude 15.7 and 1.8 x 0.4 arcminutes in size, it lies 18 arc minutes South of M51.