Orion - Orionza (English spelling) Orion

Japanese: オリオン座 - オリオンざ（英語表記）Orion

A constellation on the celestial equator that reaches its highest point in the sky in the early evening of February. Its approximate location is 5:20 hours right ascension and 3° declination. Orion is the name of a hunter in Greek mythology. It contains many bright stars, including the red alpha star Betelgeuse and the white beta star Rigel, both of which are the brightest stars in the sky. These, along with the gamma stars Bellatrix and κ, form a beautiful quadrilateral, with the three stars that make up Orion's belt lined up in the center. The three stars are almost on the celestial equator. The area south of the three stars, which corresponds to Orion's sword, contains the Orion Nebula (M42, NGC1976), which can be seen with the naked eye. Theta 1 at the center of the Orion Nebula is a very young, hot, newly born quadrilateral called the Trapezium (trapezium), which makes the nebula glow. The nebula also contains many T-type Tauri irregular variables. The nebula is about 1,500 light years away, and has been observed by radio and infrared. In addition, there is the Horsehead Dark Nebula (→ Horsehead Nebula) near the left edge of the three stars. From photographic observations, it can be seen that the entire constellation Orion is enveloped in a faint nebula.

Source: Encyclopaedia Britannica Concise Encyclopedia About Encyclopaedia Britannica Concise Encyclopedia Information

Japanese:

2月上旬の宵に南中する天の赤道上の星座。概略位置は赤経 5時20分，赤緯 3°。オリオンはギリシア神話の猟師の名。明るい星が多く，赤色のα星ベテルギウスと白色のβ星リゲルはともに全天最輝星で，これとγ星ベラトリックスおよびκ星でみごとな四辺形をつくり，その中央にオリオンの帯にあたる三つ星が並ぶ。三つ星はほぼ天の赤道上にある。三つ星の南，オリオンの剣にあたる部分は，肉眼でも見えるオリオン大星雲（M42，NGC1976）を含む。オリオン大星雲の中心にあるθ1星は生まれたばかりの非常に若い高温の四重星でトラペジウム（不等辺四辺形）と呼ばれ，この星雲を発光させている。さらにこの星雲中には多くのおうし座T型不規則変光星が含まれている。星雲までの距離は約 1500光年で，電波や赤外線でも観測されている。ほかに，三つ星の左端近くに馬頭暗黒星雲（→馬頭星雲）がある。写真観測から，オリオン座全体がかすかな星雲で包まれていることがわかる。

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