In this paper we presented UBVRI CCD photometry for three young clusters in the direction of the Carina spiral feature: NGC 3114, Collinder 228 and vdB-Hagen 99. Our results can be summarized as follows:
Putting together the results of this paper and those of previous works (Patat & Carraro 2001; Carraro et al. 2001), the Carina complex turns out to be populated by very young clusters (like Collinder 228, NGC 3324 and Bochum 11) in its inner region, and by young or intermediate age objects (like NGC 3114, vdB-Hagen 99 and Loden 165) in its outskirts.
This confirms previous suggestions by Feinstein (1995) about the existence of an age gradient in the Carina complex. We shall discuss this issue in more details in forthcoming papers, when all the clusters observed in our survey will be analysed.
Acknowledgements
G.C. acknowledges kind hospitality from ESO. This study made use of Simbad and WEBDA. The suggestions of an anonymous referee are warmly acknowledged.
Copyright ESO 2001