Night forty three - The Whirlpool Galaxy
First night out in a long while between health and weather. Returned to M 51, The Whirlpool Galaxy.
Wikipedia says - What later became known as the Whirlpool Galaxy was discovered on October 13, 1773, by Charles Messier while hunting for objects that could confuse comet hunters, and was designated in Messier's catalogue as M51.[13] William Parsons, 3rd Earl of Rosse, employing a 72-inch (1.8 m) reflecting telescope at Birr Castle, Ireland, found that the Whirlpool possessed a spiral structure, the first "nebula" to be known to have one.[14] These "spiral nebulae" were not recognized as galaxies until Edwin Hubble was able to observe Cepheid variables in some of these spiral nebulae, which provided evidence that they were so far away that they must be entirely separate galaxies.[15]
The advent of radio astronomy and subsequent radio images of M51 unequivocally demonstrated that the Whirlpool and its companion galaxy are indeed interacting.

Comments
Post a Comment