A UBV and DDO astrophysical study of the open cluster NGC 3532

Photoelectric photometry in the UBV and DDO systems is presented for 12 stars on the red giant branch of the open cluster NGC 3532. Two independent criteria have been applied to each observed star to assign membership probabilities. The results are in good agreement with those obtained from previous proper motion studies. A mean reddening |$E(B-V)=0.07\pm0.02$| has been derived from the red cluster giants. NGC 3532 has a mean ultraviolet excess |$\langle\delta(U-B)\rangle = -0.02\pm0.01$|⁠, relative to the field K giants, and a mean cyanogen anomaly |$\langle\delta\text CN\rangle=0.034\pm0.040$|⁠, both implying a nearly solar metallicity. There is no evidence for convective mixing of heavy elements or mass loss among any of the observed stars. The distribution of stars in the theoretical H–R diagram allows us to identify most of them as red giants in the core helium burning stage of evolution.