| Abstract | Color-magnitude diagrams are derived for two LMC clusters, NGC 2249 and NGC 2241. A technique is introduced for "subtracting" the field-star contribution from the cluster CMDs using CMDs from nearby LMC fields. The possibility of a "gap" in the main sequence of NGC 2249 is discussed, and, by identifying the gap as the point of core hydrogen exhaustion for stars with convective cores, the isochrones are found to be well placed relative to the turnoff. Based on these isochrones, NGC 2249 is thought to be 550 to 700×106years old, depending on the reddening and distance modulus used. NGC 2241, by virtue of its subgiant branch and giant clump and by comparison with NGC 2506, is thought to be between 3 and 4×109years old. |
