A4 'corrallT-vsn-2' correlates the wavelengths of observed lines with a list of atomic lines in the same wavelength neighbourhood to find the mean wavelength shift between observed wavelengths and modelled lines. The possible lines are from Kurucz in the region 5277 - 5510 Angstrom (0.1nm), the observed data are from Piters et al. (1988A&A...196..115P). The correlation is tested for three different temperature models with Teff from 4250-6250K. The highest correlation is found for about 39 steps of .005 Angstrom (5x.01pm). In the line-list of Piters et al. (1988A&A...196..115P) other identifications were sought for the laboratory wavelengths, in units of 0.1nm, of 5444.588 and 5493.48 as follows: -5444.59. A trial of 5445.05 ele=2600 gives better results, more consistent wavelength. -5493.52. A trial of 5493.88 ele=1400 gives better results, and more consistent wavelength. We adopt both changes for obs5, because both lead to wavelength difference of 1.96 and 1.92x0.1nm respectively with respect to the observed wavelength. This is in good accordance with the mention in Piters et al. (1988A&A...196..115P) that "by comparing the spectrum of HR 8752, it became evident that the blue shift {Delta}{lambda} of the stellar lines is about 2{AA} (or 2x0.1nm);" The table below lists the results of a correlation test between the observed wavelengths and a list of lines for three model atmospheres that have e.w.'s larger than a few times 0.1nm over the region 5277 to 5510 (0.1nm). The correlation points to a wavelength shift of about 1.95 (0.1nm). The identification of 5445.5 (0.1nm) Fe I seems quite probable from Moore et al. (1966, The Solar Spectrum 2935 A to 8770 A, Second revision of Rowland's Preliminary Table of Solar Wavelengths, National Bureau of Standards Monograph, 61). Correlation is done between the wavelengths of observed and model lines with ew larger than 0.005x0.1nm in the region 5276-5685 (0.1nm) for 3 different Kurucz models. The observed and modeled linedata are both given in units of 0.1nm for the region 5277.2-5510.2 (0.1nm). The wavelength bins are 1/20-thx0.1nm wide. The offset or starting point is 5276 (0.1nm), each point has an increment of 0.05 (0.1nm). The correlation output is in units of (0.1nm)^2^. The observed wavelengths are given as measured, but are not corrected for the velocity of the star with respect to us. The modeled lines are laboratory lines in vacuum. In the correlation process, the lines are shifted with respect to each other in increments of 0.05x0.1nm, and the product of each of the relevant bins is summed and displayed for each incremental step. In this way the mean shift can be deduced. This is a reasonable approximation, because of the small range of wavelengths we use here. The accuracy from begin to end of the wavelength region is 2 bins. (Changing to to velocity space is more accurate.) The table shows the correlation for n=0 to 64 steps for each of the three model calculations. Each step corresponds to a wavelength difference of 1*.05=0.05x0.1nm. Note: The models used are Teff=4250, 5250, 6250 K logg= 0.0, 1.0, 0.5 vt= 6.0, 6.0, 6.0 km/s --------------------------------------------- step CORREL CORREL CORREL number 4250g00v06 5250g10v06 6250g05v06 --------------------------------------------- 0 .524715 .287413 .196048 1 .368822 .296866 .335573 2 .202263 .112167 .106196 3 .221859 .064219 .015859 4 .791847 .380028 .245933 5 .136850 .048260 .037552 6 .933446 .561097 .386883 7 .916766 .574770 .367274 8 .016985 .005490 .005020 9 .319845 .210610 .134007 10 .123960 .027375 .007859 11 .187129 .028514 .003282 12 1.173210 .729673 .503341 13 .635019 .391441 .225033 14 .048850 .013874 .005815 15 .091053 .016531 .005774 16 .068590 .011670 .003178 17 .447941 .267072 .156814 18 .066238 .044933 .042935 19 .023662 .006041 .006153 20 .007043 .001384 .000864 21 .274535 .084261 .032962 22 .205286 .118520 .103096 23 .130184 .025280 .006264 24 1.069829 .580861 .300509 25 .132102 .048197 .012552 26 .093114 .040588 .051272 27 .226059 .075149 .026483 28 .331796 .186579 .200678 29 .383675 .217960 .106190 30 .028612 .001696 .002218 31 .290585 .109183 .034174 32 .125158 .022208 .019207 33 1.431933 .598629 .425939 34 .423896 .331307 .335173 35 1.183546 .679700 .464310 36 .094101 .009028 .001575 37 .256228 .152572 .104323 38 .102430 .063499 .051817 39 2.402436 1.420927 1.117377 40 .551323 .424611 .365180 41 .587744 .342907 .202247 42 2.120434 .963933 .712616 43 .320582 .187331 .138714 44 .187656 .049852 .019199 45 .606733 .332482 .161488 46 .413898 .351732 .328285 47 .082533 .031769 .033361 48 .209790 .067424 .042836 49 .009344 .006145 .010954 50 .591001 .269564 .123421 51 .106125 .018423 .004853 52 .190689 .038479 .005246 53 .253411 .107302 .053514 54 .097848 .044886 .013547 55 .068857 .012598 .009869 56 .146254 .067853 .046271 57 .105078 .034448 .022442 58 .210263 .191740 .217136 59 .385693 .290986 .298595 60 .070084 .016216 .013374 61 .154910 .119949 .150687 62 .308570 .125039 .034323 63 .567407 .478572 .413760 64 .255944 .149158 .063684 Result: The table shows maximum correlation for n=39 steps in all three model calculations. This corresponds to a wavelength difference of 39*.05=1.95x0.1nm. Thus the 'tau-lag' corresponds to 1.95x0.1nm. (end)