A photometric membership test has been carrled out for stars in the region of the open cluster M 39 (= NGC 7092 = OCL 211 = C 2130 + 482) selected by ARTIUKHINA, KALININA from proper motions to be probable members of the cluster corona. Using own UBV observations of 28 brighter (BD) stars and additional photometric data from other available sources out of the 117 probable members in the region outside of the cluster core altogether for 37 the membership could be confirmed. 22 of the stars do not belong to the cluster. The results confirm the existence of the cluster corona found statistically by ARTIUKHINA. The distribution of the confirmed members over the investigated area of about 5' diameter indicate that the corona of this poor cluster is much more extended than 75' as suggested by the statistical investigation.