Severina was the wife of Aurelian and was made Augusta c. 274. When her husband was killed in battle it's believed that she ruled, if only nominally, during the interregnal period before Tacitus was nominated the next emperor.

AE Antoninianus

RIC 3, Cohen 2 AE Antoninianus Obv: SEVERINAAVG. Diademed, draped bust right, on crescent.
Rev: CONCORDIAAVGG. Emperor standing left, clasping hands of empress standing right. Lot sold for $31 11/20/01.

RIC 4, Cohen 7 AE Antoninianus Obv: SEVERINAAVG, diademed and draped bust right, resting on a crescent.
Rev: CONCORDIAEMILITVM, Concordia standing facing, holding standard in either hand.

RIC 8, Cohen 7 AE Antoninianus Obv: SEVERINAAVG - Diademed bust right, draped and on a crescent.
Rev: CONCORDIAEMILITVM - Concordia standing left, holding two ensigns.