Alistair Göpffarth, Andreas Kowalik
We built a photometer with an adjustable amplification factor between 10 an 100 for solar observations and "astronomical lab experiments". However, in order to be able to observe stars we needed a more powerful amplifier. By using several 100x amplifiers we were able to realize an appropriate level of amplification. Furthermore, we needed an offset and a voltage divider at the input to make the amplification circuit work. Our amplifier reaches the limits of amplification and we do get thermal noise which we were able to reduce by cooling the circuit. We are planning to attempt the observation of binary stars as soon as the weather is suitable. We have already recorded measurements of a spectrum, the darkening at the edge of the sun, a "lab experiment" resembling binary stars and thermal noise.
