Hamal (Alpha Arietis) shines as the brightest star in the constellation Aries the Ram. It joins up with two other nearby stars – Sheratan and Mesarthim – to make up the Ram’s head. The triangle of stars outlining the head sits in between two prominent stellar signposts: The Great Square of Pegasus and the Pleiades star cluster.

As seen from mid-northern latitudes, Hamal lights up the eastern sky on autumn evenings, shines high in the southern sky on winter evenings, and sits in the west on early spring evenings. Hamal disappears from the night sky in April, then returns to the eastern sky before sunrise by late spring or early summer.

Nowadays, the sun passes through the constellation Aries from around April 19 to May 13

Sky chart: Wikimedia Commons. Click here for a larger version

If you could see the stars in daytime, you’d see the sun and Hamal in conjunction (north and south of one another) on or near April 24. In other words, when the sun appears due south at noon, you’d see Hamal due south at noon, too. April 24 is a little more than one month after the March equinox – the Northern Hemisphere’s spring equinox – which falls annually on or near March 20.

However, if we could backtrack some 2,500 years, we’d find the annual conjunction of the sun and Hamal happening on the March equinox. Or if we could backtrack 2,200 years, we’d find the March equinox sun in conjunction with the star Sheratan. The March equinox sun drifts westward in front of the backdrop constellations by about one degree (two sun diameters) every 72 years.

The March equinox sun shone in front of the constellation Aries from about 2,000 to 100 BCE. At present, the sun shines in front of the constellation Pisces on the March equinox. Even so, many people pay homage to the Ram and still refer to the March equinox point as the “First Point of Aries.”