I abhor the feeling of waste when throwing away a newspaper or magazine that I’ve bought but not read properly. It is more likely to find itself on a sprawling pile of catch-up reading. And so it was that I found myself picking up last month’s issue of Astronomy Now, one that had kept me company on a train journey in December. After flicking through its pages afresh, I came to thinking about the vast range and scale of human interest in the stars. It is sometimes hard to believe that the minds that give us astronomical science are from the same species that created the Greek myths. Let us take the example of the star Castor in the constellation Gemini.
Is it just that, a star in a constellation? Or is it the mortal son of Tyndareus, brother of Helen of Troy? Is it a ‘magnitude 1.93 A-class star with a mass two and a half times greater than our Sun and a surface temperature of 9,300 Kelvin’? Perhaps it is a ‘beaver’ as this is what ‘castor’ means in both Greek and Latin?
Of course it is all of these things and many more depending on the viewpoint we choose. For me, Castor is a star in the constellation Gemini, one I use to confirm that I have found Canis Minor, which I then use to find a faint star in the constellation Monoceros, this in turn gives me the Celestial Equator. The celestial equator gives me due east and west at certain times of the night. Horses for courses I suppose, or maybe that should be beavers.