Photometric observation of defunct satellites using small telescopes: preliminary results.

Detailed information on space debris characteristics is essential, among other things, to mitigate its hazards to operational satellites and people on Earth. One can perform photometric observations to get some of this information. The light curve data obtained from the observations can be analysed to identify the space debris attitude in orbit. While usually people use at least 50 cm telescopes for this purpose, smaller telescopes still have the potential. With this in mind, we have configured a system, located at Tilong Science Center in Indonesia, using less than 30 cm telescopes for photometric observations and obtained some preliminary results. We have compared the results with light curves from the same objects in the AIUB light curve database maintained by the Astronomical Institute of the University of Bern in Switzerland. In the case of defunct GLONASS satellites, as a sample, our limited result shows consistency with the reference. Our system with 20 cm reflector can reveal similar light curve morphology to the ones in the AIUB database for relatively bright objects (magnitude less than 14). Typically, four peaks appear in a phase diagram of decommissioned GLONASS satellites which resemble their four sides. On the other hand, our smaller system with 10 cm refractor, can only be used to get the inferred periods for relatively bright objects. This result, while only preliminary, is inspiring considering that the primary telescope objectives of our system are only 20 cm in maximum compared to the reference database, which uses a 1-m telescope.