Right Ascension (RA) is the angular distance of a celestial object measured eastward along the celestial equator from the vernal equinox. It is one of the coordinates used in the equatorial coordinate system to locate objects in the sky. It is typically measured in hours, minutes, and seconds and its value changes as the Earth rotates. RA is calculated using the sidereal time and the object's hour angle.
Declination (DEC) is the angular distance of a celestial object measured north or south of the celestial equator. It is also a coordinate in the equatorial coordinate system and is measured in degrees, minutes, and seconds. The declination of a celestial object can be measured using a declination circle or by calculating it from the object's altitude and azimuth coordinates.
Right Ascension and Declination are coordinates used to locate celestial objects on the celestial sphere. These coordinates do not directly relate to the horizon, but they can be used to determine the altitude and azimuth of an object, which can then be used to calculate its position relative to the horizon.
The Earth's rotation causes the positions of celestial objects to appear to change in the sky. This affects both Right Ascension and Declination, as they are both based on the Earth's rotation. As the Earth rotates, the Right Ascension and Declination of an object will change, allowing us to track its movement in the sky.
Yes, Right Ascension and Declination can be used to locate objects in the night sky. By using a star chart or a computer program, you can determine the coordinates of an object and use them to find it in the sky. However, these coordinates are not as useful for stargazing as other coordinates, such as altitude and azimuth, as they require more calculations and are more affected by the Earth's rotation.