Double Stars ~ Roy Bicknell

Roy is going to talk about his passion for Double Stars, their colours, their separations and how to measure them. Binary stars are important to stellar astronomers as knowledge of their motions allows direct calculation of stellar mass and other stellar parameters when since the beginning of the 1780s, both professional and amateur double star observers have telescopically measured the distances and angles between double stars to determine the relative motions of the pairs.

A Practical Approach to Telescope Design ~ Barry Soden

Using the Sun box as an example. It will cover the measurement of focal length of lenses, positioning of lenses to form an optical instrument, how to reduce internal reflections which degrade the image, and other practical points.