Right Ascension

Right Ascension (RA) is a coordinate used by astronomers to pinpoint the location of objects in the sky, similar to longitude on Earth. It measures how far east an object is from the "vernal equinox," a reference point in the sky, and is expressed in hours, minutes, and seconds—one hour corresponding to 15 degrees of sky. RA allows astronomers to identify when a celestial object will be visible, as the sky appears to rotate daily, making RA a crucial tool for tracking and locating stars, planets, and other celestial bodies.