DIDACTICAL EXPERIMENTS ON GRAVITATIONAL LENSING
Jean Surdej{1}{*}, Sjur Refsdal{2} and Anna Pospieszalska-Surdej{1}

{short description of image} {short description of image} 0047-28078
{short description of image} {short description of image} 1009-0252
{short description of image} {short description of image} H1413+117
{short description of image} {short description of image} PG1115+080
{short description of image} {short description of image} HE1104-1805
{short description of image} {short description of image} Abell 370
{short description of image} {short description of image} MG1131+0456

Table 1: Figures a-g represent the light from a distant source that is redistributed over the pinhole screen by symmetric (a-b) or an asymmetric (c-g) optical lens and for various positions of the pinhole (observer). Figures h-n illustrate the corresponding lensed images projected on the large screen located behind the pinhole screen and Figures o-u display known examples of multiply imaged sources (0047-28078), 1009-0252, H1413+117, PG1115+080, HE1104-1805, Abell 370 and MG1131+0456). Images (p), (r), (s) and (t) were obtained using the Hubble Space Telescope, the other ones using ground-based facilities (ESO and VLA/NRAO). Courtesy of the European Southern Observatory (ESO), the Space Telescope Science Institute (STScI) operated for NASA by AURA and the Very Large Array (National Radio Astronomy Observatory).