Chemical element named mendelevium in honor of D.I. Mendeleev, the first to arrange the elements in a periodic manner. Most recently, the synthesis of element 118 (since named oganesson) was reported in October 2006, and the synthesis of element 117 (tennessine) was reported in April 2010. Ten materials familiar to various prehistoric cultures are now known to be chemical elements: Carbon, copper, gold, iron, lead, mercury, silver, sulfur, tin, and zinc. Three additional materials now accepted as elements, arsenic, antimony, and bismuth, were recognized as distinct substances prior to 1500 AD. Phosphorus, cobalt, and platinum were isolated before 1750. Most of the
SN 2005bc of the supernova at around −18.6 at maximum, rather faint for a Type Ia event. As the supernova was of Type Ia, its progenitor star was a White Dwarf star which exceeded the Chandrasekhar limit. Below is an image of SN 2005bc and NGC 5698 taken just over a week after peak brightness. SN 2005bc SN 2005bc was a Type Ia supernova occurring in the Barred spiral galaxy NGC 5698 in the constellation of Boötes. SN 2005bc was discovered on 2 April 2005 by LOSS and independently by Tim Puckett and L. Cox. The supernova was at magnitude 16.4 at