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Canis Minor is a small constellation in the northern celestial hemisphere. In the second century, it was included as an asterism, or pattern, of two stars in Ptolemy's 48 constellations, and it is counted among the 88 modern constellations. Its name is Latin for "lesser dog", in contrast to Canis Major, the "greater dog"; both figures are commonly represented as following the constellation of Orion the hunter. Canis Minor contains only two stars brighter than the fourth magnitude, Procyon (Alpha Canis Minoris), with a magnitude of 0.34, and Gomeisa (Beta Canis Minoris), with a magnitude of 2.9. The constellation's dimmer stars were noted by Johann Bayer, who named eight stars including Alpha and Beta, and John Flamsteed, who numbered fourteen. Procyon is the seventh-brightest star in the night sky, as well as one of the closest. A yellow-white main sequence star, it has a white dwarf companion. Gomeisa is a blue-white main sequence star. Luyten's Star is a ninth-magnitude red dwarf and the Solar System's next closest stellar neighbour in the constellation after Procyon. The fourth-magnitude HD 66141, which has evolved into an orange giant towards the end of its life cycle, was discovered to have a planet in 2012. There are two faint deep sky objects within the constellation's borders. The 11 Canis-Minorids are a meteor shower that can be seen in early December. == History and mythology == Though strongly associated with the Classical Greek uranographic tradition, Canis Minor originates from ancient Mesopotamia. Procyon and Gomeisa were called ''MASH.TAB.BA'' or "twins" in the ''Three Stars Each'' tablets, dating to around 1100 BC. In the later ''MUL.APIN'', this name was also applied to the pairs of Pi3 and Pi4 Orionis and Zeta and Xi Orionis. The meaning of ''MASH.TAB.BA'' evolved as well, becoming the twin deities Lulal and Latarak, who are on the opposite side of the sky from ''Papsukal'', the True Shepherd of Heaven in Babylonian mythology. Canis Minor was also given the name ''DAR.LUGAL'', which translates to "the star which stands behind it", in the ''MUL.APIN''; the constellation represents a rooster. This name may have also referred to the constellation Lepus. ''DAR.LUGAL'' was also denoted ''DAR.MUŠEN'' and ''DAR.LUGAL.MUŠEN'' in Babylonia. Canis Minor was then called ''tarlugallu'' in Akkadian astronomy. Canis Minor was one of the original 48 constellations formulated by Ptolemy in his second-century Almagest, in which it was defined as a specific pattern (asterism) of stars; Ptolemy identified only two stars and hence no depiction was possible.〔 The Ancient Greeks called the constellation προκυων/''Procyon'', "coming before the dog", transliterated into Latin as ''Antecanis'', ''Praecanis'', or variations thereof, by Cicero and others. Roman writers also appended the descriptors ''parvus'', ''minor'' or ''minusculus'' ("small" or "lesser", for its faintness), ''septentrionalis'' ("northerly", for its position in relation to Canis Major), ''primus'' (rising "first") or ''sinister'' (rising to the "left") to its name ''Canis''. In Greek mythology, Canis Minor was sometimes connected with the Teumessian Fox, a beast turned into stone with its hunter, Laelaps, by Zeus, who placed them in heaven as Canis Major (Laelaps) and Canis Minor (Teumessian Fox).〔Apollodorus, Bibliotheca 3,192.〕 Eratosthenes accompanied the Little Dog with Orion, while Hyginus linked the constellation with Maera, a dog owned by Icarius of Athens.〔 On discovering the latter's death, the dog and Icarius' daughter Erigone took their lives and all three were placed in the sky—Erigone as Virgo and Icarius as Boötes. As a reward for his faithfulness, the dog was placed along the "banks" of the Milky Way, which the ancients believed to be a heavenly river, where he would never suffer from thirst.〔Mark R. Chartrand III (1982) Skyguide: A Field Guide for Amateur Astronomers, p. 126 (ISBN 0-307-13667-1).〕 The medieval Arabic astronomers maintained the depiction of Canis Minor (''al-Kalb al-Asghar'' in Arabic) as a dog; in his Book of the Fixed Stars, Abd al-Rahman al-Sufi included a diagram of the constellation with a canine figure superimposed. There was one slight difference between the Ptolemaic vision of Canis Minor and the Arabic; al-Sufi claims Mirzam, now assigned to Orion, as part of both Canis Minor—the collar of the dog—and its modern home. The Arabic names for both Procyon and Gomeisa alluded to their proximity and resemblance to Sirius, though they were not direct translations of the Greek; Procyon was called ''ash-Shi'ra ash-Shamiya'', the "Syrian Sirius" and Gomeisa was called ''ash-Shira al-Ghamisa'', the Sirius with bleary eyes.〔 Among the Merazig of Tunisia, shepherds note six constellations that mark the passage of the dry, hot season. One of them, called ''Merzem'', includes the stars of Canis Minor and Canis Major and is the herald of two weeks of hot weather. The ancient Egyptians thought of this constellation as Anubis, the jackal god.〔Chartrand, p. 126.〕 Alternative names have been proposed: Johann Bayer in the early 17th century termed the constellation ''Fovea'' "The Pit", and ''Morus'' "Sycamine Tree". Seventeenth-century German poet and author Philippus Caesius linked it to the dog of Tobias from the Apocrypha.〔 Richard A. Proctor gave the constellation the name ''Felis'' "the Cat" in 1870 (contrasting with Canis Major, which he had abbreviated to ''Canis'' "the Dog"),〔 explaining that he sought to shorten the constellation names to make them more manageable on celestial charts. Occasionally, Canis Minor is confused with Canis Major and given the name ''Canis Orionis'' ("Orion's Dog"). 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Canis Minor」の詳細全文を読む スポンサード リンク
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