 In May 2009 , the Joint Working Party ( JWP ) of IUPAC published a report on the discovery of copernicium in which they acknowledged the discovery of the isotope 283Cn . This implied the discovery of flerovium , from the acknowledgement of the data for the synthesis of 287Fl and 291Lv , which decay to 283Cn . The discovery of the isotopes flerovium @-@ 286 and -287 was confirmed in January 2009 at Berkeley . This was followed by confirmation of flerovium @-@ 288 and -289 in July 2009 at the Gesellschaft für Schwerionenforschung ( GSI ) in Germany . In 2011 , IUPAC evaluated the Dubna team experiments of 1999 – 2007 . They found the early data inconclusive , but accepted the results of 2004 – 2007 as flerovium , and the element was officially recognized as having been discovered . 
