Starship Asterisk*

pmason has the answer. As I observed earlier, the shape is like the upper tangent arc, but sharper than any examples in the photos I've seen. I didn't realize the angle above or below the observer's horizon made the arc sharper or more obtuse. That explains it perfectly. Comparing photos with lights...

The fans don't look like Moilanen arcs. Moilanen are parabolic, aren't they? These curve the wrong way for that. With a parabolic arc the width of the fans would increase more slowly with height. The width of these increases more rapidly with height. They do look similar to Marko Riikonen's, but the...