This past year, while working on researching the history of Ptolemy’s star catalog, I came across the following quote from Toomer:
Ideally one should provide a reconstruction of the outline of each constellation as it appears on Ptolemy’s star-globe. Unfortunately no one has done the necessary work of assembling and comparing all the literary and iconographic evidence from antiquity and from the derivative Arabic tradition (notably as-Sufi). This would be an interesting and valuable enterprise.
Essentially what Toomer is noting here is that, while historians of astronomy have spent considerable time trying to reconstruct what stars the catalog described, less attention has been paid to how the constellations looked.
Thus, I’m launching a spin-off from my main project to look at this topic.
As we’ve seen, Ptolemy’s catalog lists the positions of the stars within the figures of the constellations which gives us an excellent first pass at understanding how these constellations were envisioned. But that’s also where Toomer implies that the understanding stops.
The translation I’m using was published in the early 90’s, so it’s 30 years old at this point1 so the statement may no longer be completely accurate. Indeed, Illustrating the Phaenomena looks to start addressing this issue although I haven’t gotten my hands on a copy to see how well.
But this is part of the motivation behind this project: Inviting artisans of the known world to use Ptolemy’s descriptions, combined with the modern understanding of the positions of the stars as well as other period images, to try to envision how Ptolemy and his contemporaries envisioned the constellations.
My hope is that we’ll find some interesting things along the way. For example, do participants looking at late period sources for inspiration find that they differ from Ptolemy’s description? Are there any stars that are impossible to align with Ptolemy’s descriptions suggesting that the identifications may be wrong?
However, this exercise may just end up being pretty pictures. Which is fine too. Because a second goal of this project is to expand interest and awareness of astronomy within the SCA which this does by making portions of astronomy accessible to artisans without much math or complex concepts. Beginning with the zodiac constellations is also hopefully going to attract the interest of those interested in the astrological aspects of astronomy.
The full details of the project can be found at PtolemaicZodiac.net.