ASTR 152 Lecture Notes - Lecture 2: Celestial Equator, Dailymotion, Northern Hemisphere
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Chapter 2: the sky, the celestial sphere, the stars, and constellations, and their daily motion. The celestial phe(cid:396)e is a(cid:374)othe(cid:396) (cid:374)a(cid:373)e fo(cid:396) the sk(cid:455) that su(cid:396)(cid:396)ou(cid:374)ds us; that"s (cid:449)he(cid:396)e se(cid:448)e(cid:396)al thousa(cid:374)d stars can be seen on a clear night as if they were attached/glued to the inside of that celestial sphere. Earth rotates to the east, but stars appear to turn west (apparent rotation: celestial sphere, north/south pole and north/south celestial pole, polaris (current north star, equator and celestial equator. Constellations various shapes or patterns formed by bright stars in the sky, as viewed by early observers. Early observers also named some of the brightest stars in the sky (betelgeuse, rigel, vega, sirius, Today, brightest visible stars are named using the letters of the greek alphabet followed by the name of the constellation in a decreasing order of their observed brightness (alpha - , (cid:271)eta - , gamma (cid:563), et(cid:272). (cid:895)
