Photometric analysis of the Pi of the Sky data

Presentation duration: 15 minutes

Presenter: Malgorzata Siudek

Database containing star’s measurements from period 2006-2009 taken by the Pi of the Sky detector located in Las Campanas Observatory in Chile contains more than 2 billions measurements of almost 17 millions of objects. All measurements are available on the Pi of the Sky web site through a dedicated interface which also allows to download the selected data. Accurate analysis of Pi of the Sky data is a real challenge because of a number of factors that can influence measurements. Reading the chip with the shutter opened, strong and varying sky background, passing planets or planetoids, clouds and hot pixels are among possible sources of errors in our measurements. In order to facilitate analysis of variable stars we have developed a system of dedicated filters to remove bad measurements or frames. The spectral sensitivity of the detector is taken into account by appropriate corrections based on the spectral type of reference stars. This process is illustrated by the analysis of the BG Ind system where we have been able to reduce the systematic uncertainty to about 0.013 magnitudo.