M47
Sketch by Michael Vlasov
According to the fine folks at SEDS, M47 lies about 1600 light years away, contains around 50 stars, and spans 12 light years. Overall, the population of stars is similar to that of the Pleiades. It contains two orange K-type giants with masses about 200 times that of the sun. It is estimated to be 98 million years old and is receding from us at 9 km/sec. Charles Messier cataloged it in 1771, but due to an error in marking its position, it was not recognized as a Messier object and so re-discovered by William Herschel in 1785. In 1984, a book by Hodierna came to light in which he described the cluster as “a Nebulosa between the two dogs” in 1654, making him the original discoverer on record.
Michael,
Colorful and accurate rendering of this fine open cluster.
Frank