Age and convective core overshooting calibrations in CPD-54 810 binary system. Statistical investigation on the solution robustness [SSA]

http://arxiv.org/abs/2304.06301


Relying on precise observations for the CPD-54 810 binary system, we investigate the robustness of the estimated age and convective core overshooting for a system with both stars on the main sequence (MS). […] We adopt the SCEPtER pipeline, based on grids of stellar models computed for a different initial chemical composition and convective core overshooting efficiency. The base fit suggests a common age of $3.02 \pm 0.15$ Gyr, in agreement with recent literature. This estimated convective core overshooting parameter is $\beta = 0.09 \pm 0.01$, with a corresponding convective core mass $M_c = 0.059^{+0.017}{-0.021}$ $M{\odot}$. The robustness of these estimates were tested assuming a narrow constraint on the helium-to-metal enrichment ratio. The chemical solution of the system changes, but the age and the overshooting parameter are almost unchanged ($3.08^{+0.17}_{-0.14}$ Gyr and $0.09 \pm 0.01$). In a further test, we halved the uncertainty as to the effective temperature of both stars and again the estimated parameter shows only small variations ($3.02 \pm 0.12$ Gyr and $0.09 \pm 0.01$). This low variability suggests that the age of the system with both stars in the MS can be reliably estimated at a 5\% level, but it also indicates that the power of the investigation is probably low. […] Despite the great increase in the observational constraints’ precision, the results support the conclusions of previous theoretical works on the stellar parameter calibration with double MS star binary systems.

Read this paper on arXiv…

G. Valle, M. Dell’Omodarme, P. Moroni, et. al.
Fri, 14 Apr 23
51/64

Comments: Accepted for publication in A&A. Abstract abridged