%0 Generic %1 li2014exclusion %A Li, Chengyuan %A de Grijs, Richard %A Deng, Licai %D 2014 %K age cluster stellar %T The exclusion of a significant range of ages in a massive star cluster %U http://arxiv.org/abs/1412.5368 %X Stars spend most of their lifetimes on the main sequence in the Hertzsprung--Russell diagram. The extended main-sequence turn-off regions -- containing stars leaving the main sequence after having spent all of the hydrogen in their cores -- found in massive (more than a few tens of thousands of solar masses), intermediate-age (about one to three billion years old) star clusters are usually interpreted as evidence of cluster-internal age spreads of more than 300 million years, although young clusters are thought to quickly lose any remaining star-forming fuel following a period of rapid gas expulsion on timescales of order $10^7$ years. Here we report that the stars beyond the main sequence in the two billion-year-old cluster NGC 1651, characterized by a mass of $1.7 10^5$ solar masses, can be explained only by a single-age stellar population, even though the cluster has clearly extended main-sequence turn-off region. The most plausible explanation for the extended main-sequence turn-offs invokes the presence of a population of rapidly rotating stars, although the secondary effects of the prolonged stellar lifetimes associated with such a stellar-population mixture are as yet poorly understood. From preliminary analysis of previously obtained data, we find that similar morphologies are apparent in the Hertzsprung--Russell diagrams of at least five additional intermediate-age star clusters, suggesting that an extended main-sequence turn-off does not necessarily imply the presence of a significant cinternal age dispersion.

@misc{li2014exclusion, abstract = {Stars spend most of their lifetimes on the main sequence in the Hertzsprung--Russell diagram. The extended main-sequence turn-off regions -- containing stars leaving the main sequence after having spent all of the hydrogen in their cores -- found in massive (more than a few tens of thousands of solar masses), intermediate-age (about one to three billion years old) star clusters are usually interpreted as evidence of cluster-internal age spreads of more than 300 million years, although young clusters are thought to quickly lose any remaining star-forming fuel following a period of rapid gas expulsion on timescales of order $10^7$ years. Here we report that the stars beyond the main sequence in the two billion-year-old cluster NGC 1651, characterized by a mass of $\sim 1.7 \times 10^5$ solar masses, can be explained only by a single-age stellar population, even though the cluster has clearly extended main-sequence turn-off region. The most plausible explanation for the extended main-sequence turn-offs invokes the presence of a population of rapidly rotating stars, although the secondary effects of the prolonged stellar lifetimes associated with such a stellar-population mixture are as yet poorly understood. From preliminary analysis of previously obtained data, we find that similar morphologies are apparent in the Hertzsprung--Russell diagrams of at least five additional intermediate-age star clusters, suggesting that an extended main-sequence turn-off does not necessarily imply the presence of a significant cinternal age dispersion.}, added-at = {2014-12-18T09:04:30.000+0100}, author = {Li, Chengyuan and de Grijs, Richard and Deng, Licai}, biburl = {https://www.bibsonomy.org/bibtex/2b7991e9bc3a0b06b3bede6284645aa21/miki}, description = {[1412.5368] The exclusion of a significant range of ages in a massive star cluster}, interhash = {84d5cc1882c6fabcd7f920aa0775af2b}, intrahash = {b7991e9bc3a0b06b3bede6284645aa21}, keywords = {age cluster stellar}, note = {cite arxiv:1412.5368Comment: 9 pages, 5 figures, "Authors' version of a letter published in Nature (17 December 2014), including Methods and Extended Data."}, timestamp = {2014-12-18T09:04:30.000+0100}, title = {The exclusion of a significant range of ages in a massive star cluster}, url = {http://arxiv.org/abs/1412.5368}, year = 2014 }