Messier 51, universally often called the Whirlpool Galaxy is without doubt one of the most photogenic galaxies of all
Messier 51 (NGC 5194) in Canes Venatici is the archetypal face-on spiral galaxy. Aptly named and really nicely often called the Whirlpool Galaxy, this magnificent object has few rivals throughout your entire sky and, if the sheer quantity of photos obtained at Astronomy Now headquarters over latest years is any indicator, solely mighty Messier 31 in Andromeda is as standard.
The Whirlpool was found by Charles Messier in 1773 and essentially the most well-known observations of it had been made by William Parsons, the Third Earl of Rosse, who was the primary to substantiate its majestic spiral construction when observing via the 72-inch ‘Leviathan of Parsonstown‘ at Birr Fort in Eire. Just a few years earlier, in 1833, John Herschel noticed ‘a really vivid spherical nucleus surrounded at a distance by a nebulous ring’; this commentary is considered the primary trace of the spiral nature of the Whirlpool.
Messier 51 lies near us in cosmological phrases, a mere 23 million gentle years away. It’s not a very giant galaxy; with a diameter of 87,000 gentle years, it’s smaller than our personal Milky Means Galaxy. Advantageously, Messier 51 is introduced face-on to our line of sight, giving us a hen’s-eye view of its pronounced and swish ‘grand design’ spiral arms, that are lit-up by younger, scorching stars clusters and pinky-red H-II areas that shaped as just lately as 10 million years in the past.
Messier 51 has a smaller, interacting companion galaxy, NGC 5195 (found by Pierre Méchain in 1781; Messier noticed simply the brighter of the 2 cores [M51]), which lies instantly north and has a extremely inclined orbit round M51. Bouts of enhanced star-formation are being triggered by the shut approaches, the final of which is believed to have occurred 70 million years in the past. NGC 5195 is now receding from M51 and is estimated to lie 500,000 gentle years behind it.
Deep novice photos present M51’s distinguished north-eastern arm in entrance of NGC 5195, bisecting the smaller galaxy. Additionally they present plumes of fabric emanating from NGC 5195, tidal tails shaped from stars being flung into eccentric orbits taking them distant from the galaxy.
The Whirlpool shines at magnitude +8.1 and spans 11’ x 8.7’. It’s not too laborious to trace it down; from Alkaid (eta [η] Ursae Majoris, magnitude +1.8, the top star of the Plough’s deal with) sweep simply over two levels west to find 24 CVn (+4.7) after which head two levels south-south-west to land on M51. Messier 51 lies within the far northern sky and is circumpolar from the UK. Firstly of Might, it culminates on the zenith at 2am BST (01:00 UT).
M51’s spiral arms are of low floor brightness, rendering them more durable to identify in a hazy, moonlit or reasonably light-polluted sky. On a superb evening from a suburban location, M51 will be seen via a small telescope, whereas at a semi—rural web site it may be captured in a humble pair of 10 x 50 binoculars as a small hazy patch. Some spiral construction ought to begin to materialise via a 250mm (10-inch) telescope.
