|
Galileo was the first to reveal the truth of this 'nebulous' object, and reported: "The nebula called Praesepe, which is not one star only, but a mass of more than 40 small stars." It was probably later seen and partly resolved in 1611 by Peiresc, the discoverer of the Orion Nebula (M42), and observed as a cluster by Simon Marius in 1612. Charles Messier added it to his catalog on March 4, 1764. With larger telescopes, more than 200 of the 350 stars in the cluster area have been confirmed as members (by their common motion). Some others are foreground or background stars, and others may not yet have been determined.
M44 is most commonly known as the Beehive cluster. It is also one of the objects easily visible to the naked eye, and thus known since prehistoric times. Some ancient lore is associated with it: Greeks and Romans saw this 'nebula' as the manger. The Greek called it Phatne, associated with two donkeys who eat from it, Asellus Borealis, the Northern "Ass" and Asellus Australis, the Southern "Ass". Erathosthenes reported that these were the donkeys on which the gods Dionysos and Silenus rode into the battle against the Titans, who were frightened by the animals loud horse cry allowing the gods an easy victory. As a reward, the donkeys were put in sky together with Phatne. Other historical figures mentioned this nebula as well including Aratos in 260 B.C., Hipparchus in 130 B.C. Ptolemy mentions it as one of seven nebulae he noted in his Almagest, and Johann Bayer's chart about 1600 A.D. as "Nubilum" or "Cloudy" Object. According to the new determination by ESA's astrometric satellite Hipparcos, the cluster is 577 light years distant and its age was estimated at about 730 million years. Curiously, both this age and the direction of proper motion of M44 coincide with that of the Hyades, another famous naked-eye and Longley known cluster, which however was neither included in Messier's list nor in the NGC and IC catalogs, which is currently estimated at an age of about 790 million years. Probably these two clusters, although now separated by hundreds of light years, have a common origin in some great diffuse gaseous nebula which existed 700 to 800 million years ago. Consequently, also the stellar populations are similar, both containing red giants M44 at least 5 of them and some white dwarfs. |
Technical Information
 |
Right Ascention 8:40(Hours/mn) Declination +19.59 Distance 577 Light Years Brightness 3.7 Magnitude Apparent Dimension 95(arc/mn) Age about 730 Million Years |
|
|
|
