C/2011 L4 (PanSTARRS)

C/2011 L4 (PanSTARRS), also known as Comet PANSTARRS, is a non-periodic comet discovered in June 2011 that became visible to the naked eye when it was near perihelion in March 2013. It was discovered using the Pan-STARRS telescope located near the summit of Haleakalā, on the island of Maui in Hawaii. Comet C/2011 L4 probably took millions of years to come from the Oort cloud. After leaving the planetary region of the Solar System, the post-perihelion orbital period (epoch 2050) is estimated to be roughly 107000 years. Dust and gas production suggests the comet nucleus is roughly 1 kilometer (0.62 mi) in diameter, while based on the absolute nuclear magnitude and a geometric albedo of 0.04 the diameter of the nucleus is over 2.4 kilometers (1.5 mi). A method based on coma magnitude decay function estimated the effective radius at 2.317 ± 0.190 km.