Hipparchus: Scorpio
Scorpio is one of the most striking figures in the sky. From the three stars in its body, centered by bright red Antares, down along the seven stars of the tail, plus two in the sting – it’s easy for anyone familiar with scorpions to see the body and tail in this sweep of stars.
Many constellations leave a modern viewer wondering ‘how does anyone see a boat / chariot / goat-fish in those stars?’
Scorpio is not like that.
Our investigation of Hipparchus’ alignments based in Scorpio demonstrates how stellar alignments, anchored by easily defined stars, were used to define a number of less-bright stars. To the north, Scorpio’s tail helps define the legs and feet of Ophiuchus, while to the south the stars of Ara are fully defined by the bright stars of the Scorpion’s body and tail.
Along the way, we propose an emended version of Ptolemy’s text, in the spirit of Hipparchus’ experiment.
We’ve split this into two presentations