A little ramble through Aries the Ram

 A constellation that dates to ancient times, in legend Aries represented the Ram whose golden fleece was sought by Jason and the Argonauts. If you watch the film Jason and the Argonauts, you will get an idea of the story.

The Euphratean astronomers knew it as Gam, the scimitar the curved blade being formed from stars in Pisces and the last three bright stars in Aries. This was the weapon protecting the kingdom against the seven evil spirits or Tempest Powers. Some people think the figure was designed to represent the Egyptian King of gods shown at Thebes with ram’s horns and known by a variety of names including Amon, Hammon and Amen. The Arab astronomer Ulugh Beg 1394-1449 called the constellation Al Kabas al Alif or the Tame Lamb.

Despite not being a very bright constellation, it has assumed great importance in astronomy, because around 2,000 years ago it contained the point where the Sun passed from south to north across the celestial equator each year. This point, the vernal equinox marked the start of spring in the northern hemisphere.

This point is known as the first point of Aries. However, because of the slight wobble of the Earth which is called precession this point has now moved into the neighbouring constellation of Pisces. Having said that we still call it the First Point of Aries.

The brightest star, alpha is called Hamal which means ‘The Head of the Sheep’, it shines at magnitude 2.0 the same brightness as the North Star. Hamal lies 66 light years away and is a K class giant with a surface temperature of 4,200’C compared to 5,800’C of the Sun. The astronomers Ptolemy and Ulugh Beg both describe the horn of the ram as being over the head, Hipparchos in his star map who described it as being on the muzzle. It was the last of the great telescope astronomer Tycho who placed the horn back on the head of the ram as we see it depicted today.

The next brightest star is beta which is called Sheratan meaning ‘The Sign’ and is 60 light years away it has a magnitude of 2.7. Sheratan is an A class star with a temperature of 8,700’C much hotter than the Sun.

A line drawn from Hamal and to the left and upwards slightly will reach the third brightest star in Aries. This is 41 Arietis. I know I have said that the brightest 24 stars of each constellation have a Greek letter allocated to them. The first Astronomer Royal John Flamsteed (1646-1719) undertook a survey of the night sky and gave every naked eye star in a constellation a number, evens stars which have a Greek letter. Sometimes this system is totally disregarded.

41 Aries has a magnitude of 3.6 and is a B class star hotter than our Sun and is 166 light years distant. The star does not have a Greek letter because it was originally part of a now defunct small constellation called Musca Borealis the Northern Fly.

Just below beta you will find gamma or Mesarthim the meaning is unknown; its magnitude is 3.9 and is 164 light years away Mesarthim is a B class star much hotter than the Sun.  The star used to be called ‘The First Star of Aries’ as it was the closest visible star to the vernal equinox .

There is a meteor shower the Arietids which are active between May 22^nd and July which peaks on June 7^th. Sadly, it is invisible to the naked eye because it is a daytime meteor shower. This meteor shower and there are many daytime showers are studied by astronomers using radar or radio telescopes.

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