Dimming Objects over Lynchburg

Reporting an observed anomaly in the Southwest Sky between the moon and the star Arcturus.  There were two lights which appeared to be bright planets such as Jupiter or Venus stationary about two lunar diameters apart.  They did not move but simply began to dim and then vanished from sight.   I am an amateur astronomer and fairly familiar with the night sky. I knew there were no planets visible from my location at that time, yet these initially appeared to be planets.  The entire event duration was between 10 and 15 seconds.
I checked the Heavens-Above website to see if there may have been iridium satellites visible from my location but did not find any.  This remains a mystery to me especially since there was no movement which would preclude most logical explanations.