We observed several OB associations of M31 (OB 33, 42, 59 and 69) and of M33 (OB 4 and 137) in UBVI and through interference filters centered on lines of HeII and CIII, as well as a narrow continuum comparison filter at 4749 å (Armandroff & Massey, 1985). The observations were made at the CFH 3.6m telescope with a RCA-CCD. The stellar photometry was obtained using DAOPHOT.
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