Sky Gazing Archives

Observing the night sky and locating constellations using declination is not too difficult. On Earth, declination is comparable to the concept of latitude. If your location's latitude is within around 80 degrees of the declination of a particular constellation, then you should be able to see that constellation at some point during the course of the year. Right ascension is the name given to the angle formed along the longitudinal axis (RA for short). It determines how far an object is located to the east of the point where the vernal equinox occurs. There are (360 degrees / 24 hours) 15 degrees in one hour of right ascension. This is due to the fact that a complete rotation of the sky takes 24 hours to complete.Discover your location's latitude here (page opens in new window). The degrees of declination range from 0 to 90, with 0 representing the equator and 90 representing the highest point above it. And below zero degrees South all the way up to ninety degrees South. A note to stargazing for beginners Because of precession, the sun appears in constellations at different times than the dates listed on a zodiac chart. For example, as of 2009 the sun actually appears in the aries stars constellation, from April 19 to May 13. In tropical astrology which is based on a zodiac with reference points in the tropics, the Sun appears in Aries from March 21 to April 20. Sidereal astrology uses a system that ties the signs to the actual constellations they represent. In sidereal astrology the sun is in Aries from April 15 to May 15. Ptolemy's Greek astronomy on which the classical zodiac is based is tropical astronomy. This system defines the zodiac signs relative to the vernal equinox regardless of actual positioning.