NavList:

Thank you very much, Frank. I can see the match between the sky in the photo and the simulation you posted very clearly. Nunki and Sabik? I've never heard those names before... I understand what you're saying about the problem of estimating the horizon in the photo. I experimented with Stelarium like you suggested. Depending on where I decide to place the horizon, the latitude could change by a degree or two.

Moving on.... Is there a general mathematical solution to this problem? The class I'm working with is relatively advanced (some trig, some calculus), so math difficulty is really no issue. Ignoring longitude, if I measure the altitudes of two known stars with some exactness, is there a formula that will tell me my latitude? Frank, I read your messages about the Orion North Arrow in your NavList library here: http://fer3.com/arc/m2.aspx/Orion-North-Arrow-FrankReed-feb-2017-g38274. I understand that the arrow is intended for a rough measure of north direction and latitude, too, but for a related example: if I measure, very accurately, the altitudes of Betelgeuse and Rigel as Orion is rising, could I get my latitude directly???

Bill Anders