[split] full head in star-shaped rays

[Koen G]

This type of sun might be of a broader Tuscan origin (Florentine? Sienese? Both?), but further investigation is required.
What makes these suns interesting for Voynich comparison is that they have a full head in the middle (with hair) rather than just a face and they are surrounded by a star shape.

I've also seen these in the work of Giovanni di Paolo, who was mainly active in Siena. This is from a 1440 illustrated Dante MS You are not allowed to view links. Register or Login to view.
   

Here's an later example from a You are not allowed to view links. Register or Login to view. of You are not allowed to view links. Register or Login to view. by di Paolo. The saint is holding a star, which has a complete head and bundles of rays around it.

   

I suspect that answering the sun question will involve finding out where it first pops up in Italian (Tuscan?) art. It seems likely that Taccola was following trends of the time. The alternative is that individuals like di Paolo were inspired by Taccola's art style, and more specifically an image from a manuscript that likely remained in Siena after its completion.