A massive white dwarf member of the Coma Berenices Open Cluster
| Autor: | Dobbie, P. D., Casewell, S. L., Burleigh, M. R., Boyce, D. D. |
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| Rok vydání: | 2009 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1111/j.1365-2966.2009.14645.x |
| Popis: | We report the identification, from a photometric, astrometric and spectroscopic study, of a massive white dwarf member of the nearby, approximately solar metalicity, Coma Berenices open star cluster (Melotte 111). We find the optical to near-IR energy distribution of WD1216+260 to be entirely consistent with that of an isolated DA and determine the effective temperature and surface gravity of this object to be $T_{\rm eff}$=$15739^{+197}_{-196}$K and log $g$=$8.46^{+0.03}_{-0.02}$. We set tight limits on the mass of a putative cool companion, M$\simgreat$0.036M$_{\odot}$ (spatially unresolved) and M$\simgreat$0.034M$_{\odot}$, (spatially resolved and a$\simless$2500AU). Based on the predictions of CO core, thick-H layer evolutionary models we determine the mass and cooling time of WD1216+260 to be M$_{\rm WD}$=$0.90 \pm0.04$M$_{\odot}$ and $\tau$$_{\rm cool}$=$363^{+46}_{-41}$Myrs respectively. For an adopted cluster age of $\tau$=500$\pm$100Myrs we infer the mass of its progenitor star to be M$_{\rm init}$=$4.77^{+5.37}_{-0.97}$M$_{\odot}$. We briefly discuss this result in the context of the form of the stellar initial mass-final mass relation. Comment: accepted for publication in MNRAS |
| Databáze: | arXiv |
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