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Are the stars always the same?
Home » Astronomy » Learning the Night Sky » Are the stars always the same?The sky changes just a little bit from night to night—revealing different stars as the year progresses. To understand how the stars appear, imagine a globe around us and paint the stars we can see from anywhere on our planet on the inside of it. This is called the celestial sphere.
Just like a globe, the celestial sphere has poles and an equator and is divided by lines called Declination (Dec) and Right Ascension (RA)—like latitudes and longitudes on an earthly globe. Dec is the north and south measurement and its terms are expressed in degrees. RA is the angle from celestial equator. Instead of using degrees, its coordinates are measured in hours eastward from the point in Pisces where the ecliptic plane meets the celestial equator.
The celestial sphere is not tilted on its axis and the stars always remain the same. While the distant stars are moving, it would be hundreds of years before we noticed. Unless you move to another part of the Earth, you will see the same stars from our little window on the sky. They will change from night to night until our “window” has made a full circle of the celestial sphere.
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