Image acquired by the TORTORA camera with an exposure time of 0.13 seconds. The selected stars are labeled using the identification number (id number) as tabulated in Tycho-2 catalogue. They have been chosen as reference stars to test the linearity and the homogeneity of the instrument (see text for more details). The center coordinates of the image are at the position: RA(J2000) = 18 h : 37 m : 05.28 s, DEC(J2000) = −06 d : 29 : 38.04. Real time images of the TORTORA system are available using the public graphical user interface at the following address: http://polaris.merate.mi.astro.it/trem/.
