Table 2
Model parameters.
| Parameter | Description | Initial value | Limit | Fit # | |||
|
|
|||||||
| 1 | 2 | 3 | 4 | ||||
|
|
|||||||
| p0, ..., p5 | Limb darkening coefficients | From Neckel & Labs (1994) | √ | √ | √ | ||
| δr | r coordinate adjustment |
|
√ | √ | |||
| FWHM S | width of seeing Gaussian | 5′′ | > 0 | √ | √ | ||
| c 1 | 1st NGK weight | 0.33% | > 10-5 | √ | √ | ||
| FWHM 1 | 1st NGK width | 57′′ | √ | √ | |||
| c 2 | 2nd NGK weight | 0.33% | > 10-5 | √ | √ | ||
| FWHM 2 | 2nd NGK width | 114′′ | √ | √ | |||
| c 3 | 3rd NGK weight | 0.33% | > 10-5 | √ | √ | ||
| FWHM 3 | 3rd NGK width | 667′′ | √ | √ | |||
| c 0 | FWK weight | 1.0% | > 0 | √ | √ | ||
| α, β, γ, σ | FWK parameters, see Table 3 | Set to make FWHM0 ≈ R⊙ | >0 | √ | √ | ||
Notes. The checks in columns with headings 1–4 indicate which parameters were fit (not fixed) in the consecutive fits (see Table 4). The far wing kernel (FWK) parameters are initialized to make the FWHM equal to 
; the Moffat β parameter is initialized to unity (making it start as a Lorentzian). The table shows the initial values for the near-limb Gaussian kernel (NGK) parameters ci and FWHMi for the NGauss = 3 fits. For NGauss = 1: c1 = 1%; FWHM1 = 97″. For NGauss = 2: c1 = c2 = 0.5%; FWHM1 = 67″; FWHM2 = 381″. The widths of the NGKs were limited during the 3rd fit to make sure they did not degenerate but not during the final 4th fit. The initial value for δr is meant to tell mpfit the expected order of magnitude.
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