Element 115 is ununpentium, which is an element that has the atomic number 115 on the periodic table. It is an extremely rare and unusually heavy element that was added to the periodic table in 2013.
Ununpentium is thought to occur in nature only for a few seconds after a star goes supernova. It can be created in a lab by fusing calcium-48 with americium, but it decays after a few milliseconds. The element was originally created in Russia in 2004, but it was not confirmed until 2013 when a team of Swedish scientists were able to replicate it. As of May 2015, ununpentium is the temporary name for this element.