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Intermediate band and H-beta observations of stars in the clusters NGC 2451, Cr 140, Cr 135, Cr 173, IC 2391, and Cr 132 in Puppis-Vela are discussed. Photometric and astrometric parameters for the stars are shown and discussed, along with light and color curves, color-luminosity arrays, histograms for reddening and luminosity, and stellar distributions. Cr 132 consists mainly of members of CMa OB2 plus a few stars that may be an extension of Cr 140. The latter is an elongated cluster of some 20 stars, 450 pc distant, 30 million years old, and with (U,V,W) = (+27,-6,-16) km/s. Cr 135 has only eight members, including a K2 Ib star, some 30 million years old, 310 pc distant, and (U,V,W) = (+13,-11,-12) km/s. For NGC 2451, extensive photometry reveals no cluster. Cr 173 is in the Vela sheet and may contain Gamma Vel and the cepheid AH Vel. IC 2391 is a very extended cluster including about two dozen stars brighter than the sun, some 30 million years old and 165 pc distant, with (U,V,W) = (+20,-19,-3) km/s.
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O. J. Eggen (1983) studied this question.
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