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arXiv · 1802.09581

The overlooked role of stellar variability in LMC intermediate-age clusters

R. Salinas
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Abstract

Broad, extended main sequence turnoffs seen in the majority of the intermediate-age (1-3 Gyr) LMC star clusters, have been interpreted as the result of an extended star formation history and/or the effect of extreme stellar rotation. A more fundamental explanation may be given by stellar variability. For clusters in these age range, the instability strip crosses the upper main sequence producing a number of variable stars (known as Delta Scuti) which, if nor properly taken into account, could appear as an extended turnoff. First results of a variability program in the LMC cluster NGC 1846 reveals a sizeable number of this type of variables, although still too low to produce a meaningful broadening, with the caveat that the true variable content of the center of this and other clusters in the LMC will only be revealed with a dedicated HST program.

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R. Salinas. 2018-02-26. The overlooked role of stellar variability in LMC intermediate-age clusters. https://arxiv.org/abs/1802.09581

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