This page hosts an interactive calculator that estimates the critical value for coevality of two binary stars.
If you use the calculator, please acknowledge the following paper:
Valle G., Dell'Omodarme M., Prada Moroni P.G., Degl'Innocenti S. (2015). A statistical test on the expected difference on grid-based binary stars age estimates. In preparation.
Input
The following information are required:- M1: the mass of the primary star in solar unit (range: 0.80 - 1.60 Msun).
- M2: the mass of the secondary star in solar unit (range: 0.80 - 1.60 Msun).
- Metallicity: the metallicity [Fe/H] of the primary star.
- r: the relative age of the primary star, defined as the ratio of the age af the star and the age at the TAMS.
- Delta Teff: error on the effective temperature (in K).
- Delta [Fe/H]: error on the metallicity (in dex).
- Delta M: relative error in the mass determination (range: [0.0; 1.0]).
- Delta R: relative error in the radius determination (range: [0.0; 1.0]).
Output
The following information are computed:- W0.95: the critical value at level 0.05.
- beta W0.95: the approximated critical values from the beta distribution.
Details
For the computations, the following correlations ara assumed:
- rho = 0.95 between the two effective temperatures
- rho = 0.95 between the two [Fe/H]
- rho = 0.8 between the two masses
- rho = 0.0 between the two radii.
Computation
Please provide the required input, press the button "Compute...", and wait a few seconds.