This star- and galaxy-studded picture was captured by Hubble’s Vast Subject Digital camera 3 (WFC3), utilizing knowledge that had been collected for scientific functions. The article of curiosity was a galaxy that’s seen in the backside left nook of the picture, named SGAS 0033+02. What makes this specific galaxy fascinating is a bit uncommon — it seems not simply as soon as on this picture, however thrice. The thrice-visible galaxy is a bit tough to identify: it seems as soon as as a curved arc simply to the higher proper of the very shiny star, and twice extra as small spherical dots above the star and to the proper of the star respectively.
SGAS 0033+02’s a number of appearances in the similar picture are usually not the consequence of an error, however as an alternative are as a result of a exceptional phenomenon often called gravitational lensing. Gravitational lensing happens when the gentle from a really distant galaxy — similar to SGAS 0033+02 — is curved (or ‘lensed’) by the gravity of a large celestial object that lies in the foreground, between the distant galaxy and the Earth. SGAS 0033+02 was found by its namesake, the Sloan Big Arcs Survey (SGAS), which aimed to establish extremely magnified galaxies that had been gravitationally lensed by foreground galaxy clusters. SGAS 0033+02 is of particular curiosity as a result of of its extremely uncommon proximity in the sky to a really shiny star. The star is beneficial, as a result of it may be used to calibrate and proper observations of the lensed SGAS 0033+02.