Beehive Cluster

In 1609, Galileo first telescopically observed the Beehive and was able to resolve it into 40 stars. Charles Messier added it to his famous catalog in 1769 after precisely measuring its position in the sky. Along with the Orion Nebula and the Pleiades cluster, Messier's inclusion of the Beehive has been noted as curious, as most of Messier's objects were much fainter and more easily confused with comets. Another possibility is that Messier simply wanted to have a larger catalog than his scientific rival Lacaille, whose 1755 catalog contained 42 objects, and so he added some well-known bright objects to boost his list. Wilhelm Schur, as director of the Göttingen Observatory, drew a map of the cluster in 1894. map of the Beehive Cluster in 1894Ancient Greeks and Romans saw this object as a manger from which two donkeys, the adjacent stars Asellus Borealis and Asellus Australis, are eating; these are the donkeys that Dionysos and Silenus rode into battle against the Titans. Hipparchus (c.130 BC) refers to the cluster as Nephelion ("Little Cloud") in his star catalog.), describing it as "The Nebulous Mass in the Breast (of Cancer)". Aratus (c.260–270 BC) calls the cluster Achlus or "Little Mist" in his poem Phainomena. Bayer also cited the name Melleff or Meeleph for the cluster, from Arabic ''Al Ma'laf, the Stall; as Meleph'', this name is also now applied specifically to the star Epsilon Cancri. This perceived nebulous object is in the Ghost (Gui Xiu), the 23rd lunar mansion of ancient Chinese astrology. Ancient Chinese skywatchers saw this as a ghost or demon riding in a carriage and likened its appearance to a "cloud of pollen blown from willow catkins". It was also known by the somewhat less romantic name of Jishi qi (積屍氣, also transliterated Tseih She Ke), the "Exhalation of Piled-up Corpses". It is also known simply as Jishi (積屍), "cumulative corpses". == Morphology and composition ==

Like many star clusters of all kinds, Praesepe has experienced mass segregation. This means that bright massive stars are concentrated in the cluster's core, while dimmer and less massive stars populate its halo (sometimes called the corona). The cluster's core radius is estimated at 3.5 parsecs (11.4 light years); its half-mass radius is about 3.9 parsecs (12.7 light years); and its tidal radius is about 12 parsecs (39 light years). So far, eleven white dwarfs have been identified, representing the final evolutionary phase of the cluster's most massive stars, which originally belonged to spectral type B. Brown dwarfs, however, are rare in this cluster, probably because they have been lost by tidal stripping from the halo. A brown dwarf has been found in the eclipsing binary system AD 3116. The cluster has a visual brightness of magnitude 3.7. Its brightest stars are blue-white and of magnitude 6 to 6.5. 42 Cancri is a confirmed member. == Planets ==

In September 2012, two planets which orbit separate stars were discovered in the Beehive Cluster. The finding was significant for being the first planets detected orbiting stars like Earth's Sun that were situated in stellar clusters. Planets had previously been detected in such clusters, but not orbiting stars like the Sun. In 2016 additional observations found a second planet in the Pr0211 system, Pr0211 c. This made Pr0211 the first multi-planet system to be discovered in an open cluster. The Kepler space telescope, in its K2 mission, discovered planets around several more stars in the Beehive Cluster. The stars K2-95, K2-100, K2-101, K2-102, K2-103, and K2-104 host a single planet each, and K2-264 has a two-planet system. ==Gallery==

File:Comet-Neat-Messier-44.jpeg|Photo of comet C/2001 Q4 (NEAT) next to Messier 44 File:M44 Heggie.jpg|Widefield image of the Beehive Cluster File:Warning- Planets Crossing! (iotw2553a).tiff|Composite time-lapse showing Mars (upper track, April–May 2025) and Venus (lower track, August–September 2025) passing through the Beehive Cluster. Image by Petr Horálek. ==See also==