Individual astronomers have recognized a number of objects as dwarf planets or as likely to prove to be dwarf planets. In 2008, Tancredi et al. advised the IAU to officially accept Orcus, Sedna and Quaoar as dwarf planets (Gonggong was not yet known), though the IAU did not address the issue then and has not since. Tancredi also considered the five TNOs Varuna, Ixion, 2003 AZ 84, 2004 GV 9, and 2002 AW 197 to most likely be dwarf planets as well. Since 2011, Brown has maintained a list of hundreds of candidate objects, ranging from "nearly certain" to "possible" dwarf planets, based solely on estimated size. As of 13 September 2019, Brown's list identifies ten trans-Neptunian objects with diameters then thought to be greater than 900 km (the four named by the IAU plus Gonggong, Quaoar, Sedna, Orcus, (307261) 2002 MS 4, and Salacia) as "near certain" to be dwarf planets, and another 16, with diameter greater than 600 km, as "highly likely". Notably, Gonggong may have a larger diameter (1230 ± 50 km) than Pluto's round moon Charon (1212 km).