Astronomy Learning and Research / Beginning Astronomy / Observational Astronomy

The Analemma – Or, how I spent my summer vacation.

Analemma
Analemma

And my spring break, Christmas vacation, birthday and, well you get the idea.

So I spent the last year of my life running home at lunch, watching weather reports and planning when I could get the next dot on my analemma. So here’s the end result. Yes, that’s it.

I was thrilled to see the figure 8, however as you can see, I’m a little off center. It should be going straight up the center of the page. I’m a little off to the left. That means that I took my readings a tad early, a result of taking readings at noon by the clock. I should have used solar noon.

Solar noon is when the sun is at it’s highest in the sky. It actually happens at different times everyday, but you can calculate the ‘average’ time of solar noon. File that under ‘things to do differently next time’. HA – next time – I don’t think so!

Before I took it off the frame, I measured the distance from the tip of the gnomon to the dots marking the solstices and the equinoxes. I also had to measure the exact height of the gnomon.

These measurements are needed to complete the first activity, which is: with reference only to your analemma and measured dimensions of your observing apparatus, calculate (1) the tilt of the Earth’s axis relative to its orbital plane, and (2) your observing Latitude.

Easy right? Well as it turns out, not too bad! But you’ll have to stay tuned!

Amy