The “Pi of the Sky” collaboration searches for optical transients associated with Gamma Ray Bursts (GRB) – the most powerful natural phenomena of astrophysical origin known to mankind. Such flashes of gamma rays occur randomly on the celestial sphere, usually twice per day, and can last from seconds to several minutes. An enormous amount of energy emitted during a GRB is directed in a narrow cone, what allows us to observe gamma ray bursts located billions of light years away. Since timing and location of a next GRB cannot be predicted the astronomers have to observe continuously as wide field of view (FOV) as possible in order to increase their chances of detecting a burst. And this is the main principle of operation of “Pi of the sky” project. We are developing, building and operating our own robotic telescopes with wide FOV dedicated to a continuous survey of the night sky with good time resolution (~10 s exposures). We are also observing: variable stars, Near Earth Objects, artificial satellites, space debris, etc.
In October 2010 the first full-scale “Pi of the Sky” paralactic mount equipped with 4 CCD cameras was installed on the Atlantic coast of Spain in INTA – El Arenosillo observatory in Mazagón near Huelva (see exact location on the map).
In July 2013 the “Pi of the Sky” experiemnt was moved into the bigger dome on top of a newly built observation platform at the INTA – El Arenosillo site. The new dome hosts 4 robotic-telescopes and 16 CCD cameras in total. Hence, the first fully equipped “Pi of the Sky” observatory becames a reality!
Each camera is equipped with a CCD chip of 2000 × 2000 pixels and with CANON EF lenses of the focal length f = 85 mm (f/d = 1.2), what corresponds to the FOV of 20° × 20°.
Each paralactic mount is carrying 4 cameras which can be aligned either in DEEP observation mode (i.e. all cameras have the same FOV) or in WIDE mode (i.e. cameras observe adjacent fields and the total FOV is 40° × 40°).
Therefore our new site in Spain is able to survey up to 80° × 80° of the celestial sphere (when all the mounts work in the WIDE mode) what corresponds to a solid angle of about 2 steradians. The total FOV of all 16 cameras is comparable to the geometrical acceptance of the Burst Alert Telescope (BAT) gamma ray detector onboard the SWIFT satellite dedicated to GRB studies. If the mounts are instructed to follow the FOV of the SWIFT spacecraft, then upon a GRB alert from the satellite, at least one of our cameras will be already observing the interesting field and will provide data before-, during- and after the burst.
The design, construction and software of the detectors have been carried out by Polish scientists and engineers from: Faculty of Physics of the University of Warsaw, National Centre for Nuclear Research, Space Research Centre and Center of Theoretical Physics of the Polish Academy of Sciences, and Institute of Electronic Systems of the Warsaw University of Technology. The construction of the new observation platform and all the instruments have been founded from a research grant from the National Science Centre of Poland under supervision of the Polish Ministry of Science and Higher Education. The new site is a result of the formal agreement signed by the University of Warsaw and the Instituto de Astrofísica de Andalucía – CSIC. The installation would not be possible without help of the BOOTES team and the management and staff of the INTA site.
Some photos of our new observatory in Spain are posted below (click on the picture to enlarge):