It took me long and long hours to clean this Byzantine Follis. I could recognize the large M on reverse, along with the last 5 letters in right field RPAUG. The obverse is very poor in condition, but the star is visible in left field as well as the Cross within a square just above the head of the Emperor. All I need is a mere guess of the Emperor's name. It might be a rare one. Thank you. LOL..
The mintmark is clearly CON (Constantinople). Vertically at reverse left is ANNO but I can't make out the year date at right.
You're right. That's Heraclius. I searched again and found the nearest match on Wildwinds. SB 804. Thank you.