JosÃ© J. ChambÃ³
GSO 8″ 760mm. f/3.8 & Atik 383L+
Comet C/2017 O1 (ASASSN) photographed on November 19th 2017. Its brightness has dropped clearly during the last month until magnitude 10 approximately. In this image taken when comet is going on Cepheus constellation toward celestial north pole, shows a green-bluish coma of 7′ diameter and a tail also more faint and short until near 10′ lenght.