The effect of solar flares, coronal mass ejections, and solar wind streams on Venus’ 5577 Å oxygen green line

We observed the Venusian 5577.3 Å OI (1S–1D) (oxygen green line) nightglow emission feature after solar flares, coronal mass ejections (CMEs), and solar wind streams from December 2010 to July 2012 using the high resolution Astrophysical Research Consortium Echelle Spectrograph on the Apache Point Observatory 3.5 m telescope. For the first time since 2004, we detected the green line. The emission is highly temporally variable, with the strongest emission detected being comparable to the previously known brightest detection, and to occur after each of the three types of solar events. We find the greatest emission occurs after CMEs and suggest that particle precipitation is the main contributor to green line emission.