After getting up late again - there was breakfast to be found - although it was lunchtime. Later I found some cake and coffee with a friend before starting the trip to the observatory.
Today we'll be looking at some key stars to try and work out how bright they are and what effect the angle ot looking at them has on the amount of light. This is called the light extinction plot, and gives you a simple equation that relates the angle you are looking at the star to the amount of light absorbed at a couple of wavelengths. In this way you can compensate for the angle you're looking at a star for and get a much closer idea of its real magnitude.
We had our planning session and picked two stars that we might go for, despite the weather looking pretty unspectacular.
The night was cloudy so we didn't get any real data, although we went through the usual procedures of setting up and parking the telescope.
We had to look at stars in both B and V bands and do various calculations on them. There was also a lot of work on errors that we had to work through.