Note 4 — II THE CONSTELLATIONS OF THE SOUTH: ANCIENT GROUPS
Reading edition
Right ascension in the skies corresponds with longitude on earth, but is more often reckoned in time than in degrees. For instance, R.A. 1 hour 35 minutes, the right ascension of Achernar, means that this star will be on the meridian 1 hour 35 minutes later than the “first point of Aries”—that is, the point at which the equator cuts the ecliptic at the spring equinox, the fundamental point corresponding with Greenwich in earthly longitude.