The Whirlpool Galaxy (also known as Messier 51a, M51a, or NGC 5194) is a spiral galaxy located at a distance of approximately 23 million light years in the constellation Canes Venatici It is one of the most famous spiral galaxies in the sky. The galaxy and its companion (NGC 5195) are easily observed by,amateur astronomers and the two galaxies may even be seen with binoculars The Whirlpool Galaxy is also a popular target for professional astronomers, who study it to further understanding of galaxy structure (particularly structure associated with the spiral arms) and galaxy interactions.

M51, also known as NGC 5194, is having a close encounter with a nearby companion galaxy, NGC 5195.

The companion's gravitational pull is causing turbulence in M51's gas and dust clouds triggering star formation in them, as can be seen by the many luminous clusters of bright, young, energetic stars. These bright clusters are highlighted in red by the light from associated glowing hydrogen gas.

Astronomers can see for the first time intricate structure in the dust clouds. Along the spiral arms, dust "spurs" can be discerned that branch out almost perpendicular to the main spiral arms.
This image was taken 28.03.09 with the Canon 300D SLR mounted on the Skywatcher ED80 refractor. 8 images were taken at ISO 400 and 5 minute exposures.2 dark frames were taken and all were combined,stacked and processed in Images Plus.copyright K.Grice 2009

The Whirlpool Galaxy – M51

M51 was discovered by Messier in October 1773 and
catalogued by him in January 1774. It has a
companion galaxy, NGC 5195, which was
discovered in 1781 by Messier's colleague, P.
Mechain.
M51, became known as the 'Whirlpool Galaxy' after
Lord Rosse discovered its famous spiral structure in
1845 with his 72-inch,1.83 m) reflecting telescope
It is situated in Canes Venatici and can be found by
following the easternmost star of the Big Dipper
(Urase Majoris), and going 3.5° southeast. Its
declination is +47°, making it a curcumpolar object
for observers located above 43°N latitude. It reaches high altitudes throughout the norther hemisphere making it an ac cessible object from the early hours in winter through the end of spring season, after which observation is hindered in lower latitudes.
.M51 is visible through binoculars under good conditions and can be resolved in detail with modern amateur telescopes. When seen through a 100 mm telescope the basic outlines of M51 and its companion are visible. Under dark skies, and with a moderate eyepiece through a 150 mm telescope, M51's spiral structure can be detected.. A larger instruments and good conditions, are required to see the spiral bands and the attachment to it’s companion M51B.
The M51 system is a spectacular example of interacting galaxies – it’s companion - NGC 5195 (m51B) is being "ripped apart" by the huge gravitational disturbance of M51, while M51 has in turn undergone huge structural alteration from the gravitational effects of NGC 5195.
The distance of M51 is estimated to be about 37 million light years. The diameter is approximately 100,000 light years and the total mass is estimated to be the equivalent of 160 billion suns. In 2005 a supernova (SN 2005cs)) was observed in the Whirlpool Galaxy, peaking at apparent
magnitude of 14...

This image was taken 20th Feruary 2010 with a Canon 40D Modified DSLR and a Stellarview 102ED Refractor......The 3 hour exposure was broken down into 36 x 5 minute images @ ISO 400. 30 minutes of Dark Subtraction was used. The evening temperature was -3 degrees, the seeing was 5/10, and I do suffer from average light pollution...Guiding via the Toucam and Meade 12" , and K3CCD. Captured in Nebulosity, alligned and stacked. Digital Development in Images Plus, and Levels and Curves applied in Photoshop CS2.

This image of M51, The Whirlpool Galaxy, in Ursa Major, was taken with my 12" Meade LX 200 Telescope.on 25.02.10...Canon 40D attached to the eyepiece at f / 10......24 x 300 second @ ISO 400 ( 2 hours exposure )....Guiding with a 102mm ED Refractor and a modified Philips Toucam connected via K3CCD tools....Captured in Nebulosity, aligned and stacked.  Final levels and curves in Photoshop CS2.

One of the most striking features of M51 in this image are the dust lanes in the spiral arms. The pronounced spiral structure is a result of M51's current encounter with its neighbor, NGC 5195. Due to this interaction, the gas in the galaxy was disturbed, resulting in the formation of new young stars.

M51 - The Whirlpool Galaxy in Canes Venatici shines at magnitude 8.4. This spiral galaxy is interacting with its small companion galaxy. This galaxy is a great target and one you'll never forget if the sky is dark, but it is quite sensitive to light pollution, which easily makes it fade into the background. Under very good conditions, suggestions of its spiral arms can be seen with a four-inch telescope at low magnification.

M51 - The Whirlpool Galaxy in Canes Venatici shines at magnitude 8.4. This spiral galaxy is interacting with its small companion galaxy. This galaxy is a great target and one you'll never forget if the sky is dark, but it is quite sensitive to light pollution, which easily makes it fade into the background. Under very good conditions, suggestions of its spiral arms can be seen with a four-inch telescope at low magnification.

M51 - The Whirlpool Galaxy in Canes Venatici shines at magnitude 8.4. This spiral galaxy is interacting with its small companion galaxy. This galaxy is a great target and one you'll never forget if the sky is dark, but it is quM51 - The Whirlpool Galaxy in Canes Venatici shines at magnitude 8.4. This spiral galaxy is interacting with its small companion galaxy. This galaxy is a great target and one you'll never forget if the sky is dark, but it is quite sensitive to light pollution, which easily makes it fade into the background. Under very good conditions, suggestions of its spiral arms can be seen with a four-inch telescope at low magnification.ite sensitive to light pollution, which easily makes it fade into the background. Under very good conditions, suggestions of its spiral arms can be seen with a four-inch telescope at low magnification.