What is meant by “Right Ascension” and “Declination”?
In reading star maps, coordinate lines are often drawn in and refer to Right Ascension (R.A.) and Declination (Dec.). These are simply astronomical “buzz-words” for sky longitude and latitude. They are very much like Earth longitude and latitude; in fact, they are based on Earth’s coordinates. Imagine extending the equator and poles of the Earth out onto the sky — if you could mark them with something visible, you would see the celestial poles and celestial equator.
