COMETARY ACTIVITY AT 25.7 AU: HALE-BOPP 11 YEARS AFTER PERIHELION

摘要

Eleven years after its perihelion, comet C/1995 O1 (Hale-Bopp) is still active. Between 2007 October 20 and 22, we detected a diffuse coma of 180 × 10~3 km in diameter with a slight elongation toward the north-south direction. The integrated brightness wa