This coin is fairly common, but I like the long-necked bust and the reverse is really sharp.
RIC also attributes another issue just like this to Mediolanum, only differentiated by the bust -- Eastern necks are longer (like this one) while Western are shorter.
This coin celebrates the victory of Aurelian over the Palmyrene Empire (note the Eastern headgear of the captive) and the reverse translates as "the rising star of Augustus"
Aurelian
A.D. 270- 275
Ӕ Antoninianus
21x23mm 3.3gm
IMP AVRELIANVS AVG; radiate & cuirassed bust right.
ORIENS AVG; Sol standing left, right hand raised and left holding globe, captive at feet.
In ex. P
RIC Vi Serdica 276