Syntax:
-Starspot <aov | ls | spec | "fix" period | "fixcolumn" <colname | colnum>> a0 b0 alpha0 i0 chi0 psi00 mconst0 fitP fita fitb fitalpha fiti fitchi fitpsi fitmconst correctlc omodel [model_outdir] Example 1.$ ./vartools -i EXAMPLES/3.starspot -oneline \ -aov Nbin 20 0.1 10. 0.1 0.01 5 0 \ -Starspot aov 0.0298 0.08745 20. 85. 30. 0. -1 \ 1 0 0 1 1 1 1 1 0 1 EXAMPLES/OUTDIR1/ Name = EXAMPLES/3.starspot Period_1_0 = 3.07960303 AOV_1_0 = 2861.35783 AOV_SNR_1_0 = 605.83431 AOV_NEG_LN_FAP_1_0 = 4755.85353 Period_2_0 = 3.08383230 AOV_2_0 = 2559.76138 AOV_SNR_2_0 = 541.88234 AOV_NEG_LN_FAP_2_0 = 4578.45788 Period_3_0 = 3.10356260 AOV_3_0 = 2165.11113 AOV_SNR_3_0 = 458.19878 AOV_NEG_LN_FAP_3_0 = 4314.25066 Period_4_0 = 6.36005672 AOV_4_0 = 1514.99364 AOV_SNR_4_0 = 320.34471 AOV_NEG_LN_FAP_4_0 = 3762.76328 Period_5_0 = 3.19393583 AOV_5_0 = 1026.91829 AOV_SNR_5_0 = 216.85084 AOV_NEG_LN_FAP_5_0 = 3185.86267 Starspot_Period_1 = 3.12218969 Starspot_a_1 = 0.02980 Starspot_b_1 = 0.08745 Starspot_alpha_1 = 22.51312 Starspot_inclination_1 = 69.03963 Starspot_chi_1 = 30.00411 Starspot_psi0_1 = 0.00000 Starspot_mconst_1 = 10.16641 Starspot_chi2perdof_1 = 26.58796
Find the rotation period of the simulated light curve EXAMPLES/3.starspot using the -aov command, and then fit a Dorren 1987 single-starspot model to the light curve. Take the period from the -aov command, take 0.0298 and 0.08745 for the parameters a and b, and set the initial values of the spot radius, stellar inclination, spot latitude, and spot longitude to 20., 85., 30., and 0. degrees, respectively. Have the routine automatically determine the initial value for the unspotted photosphere magnitude (by giving -1 for the initial value). We set the flags to vary the period, spot radius, inclination, latitude, longitude, and unspotted magnitude. We keep a and b fixed. We do not subtract the model from the light curve. We output the best-fit model to the directory EXAMPLES/OUTDIR1 (the filename will be 3.starspot.starspot.model). The light curve was simulated with parameters P = 3.12345, a=0.0298, b=0.08745, alpha=30., i=90., chi=45. Due to degeneracies in the model, the recovered values are substantially different from the input values.
Fig 1. Starspot Model Fit from Example 1.