2. Application of the IRFM to ISO calibration stars

2.1. Use of published narrow band infrared magnitudes

Two studies (I and II) of stellar temperatures and angular diameters determined using the IRFM with narrow band filters have recently been published (Blackwell et al. 1990) and Blackwell & Lynas-Gray (1994). The second of these two studies (II) presents potentially more accurate results through the use of new Kurucz LTE line-blanketed model atmospheres instead of the MARCS code of Gustafsson et al. (1975), which was used in study (I), for calibration of the method. However, the results given by these two studies differ only very slightly: the ratio of the temperatures , and the standard deviation of the ratio . In view of the closeness of the results of these two studies, we incorporate them in our analysis of new data.

2.2. The database of magnitudes in the visible region

In the subsequent sections, values for the Geneva photometric quantities (B-V) and (B2-V1) have been taken from Rufener (1988). Those for (b-y) magnitudes have been taken chiefly from Heck (1977), Olsen (1977, 1983, 1993).

2.3. The database of infrared magnitudes

The temperatures discussed in this paper are based on stellar photometry in the J, H, K and L regions, obtained by van der Bliek et al. (1996), hereafter ESO data, and by Dr. P. Hammersley (to be published) using the Carlos Sánchez telescope at the Observatorio del Teide, hereafter TCS data. Because of the limitations of the IRFM, we have restricted the range of stars to those with temperatures between 4200 K and 10000 K and surface gravities between and 4.5. The IRFM is unsuitable for hotter stars because they have a large and uncertain ultraviolet contribution to the integrated flux, and in addition, the interstellar extinction is less reliable in this region. Stars cooler than 4200 K have not been considered because infrared fluxes at longer wavelengths would be needed.

2.4. Absolute flux determinations

The filter profiles from the sources listed in Sects. 2.1 and 2.3 ranged from narrow to wide, so that several different calibrations were needed. All data were reduced by integration of the stellar flux distribution and atmospheric transmission profiles over the filter profiles to give a flux at a particular chosen wavelength. These fluxes were converted to absolute fluxes using Vega fluxes determined by Walker & Cohen (1992), based on the very careful and thorough work by Cohen et al. (1992). When all of the data had been used for the determination of temperature, it became clear that determinations using the wide J filters were less reliable because of the complexity of the filter profiles and the complication caused by some stellar and telluric absorption lines in that region. Accordingly, some of the J filter temperature determinations have either been given lower weight or have been rejected.

Because of the difficulty of determining accurate monochromatic fluxes from the more complex filter profiles, we have tried, for checking purposes only, a completely different method based on the previously published narrow band determinations. There are stars that are common between this original study and the ISO calibration list. Believing that the results of the original study are of good accuracy because of the unique suitability of the narrow band filters, we can use these stars to determine filter factors that should be used in the ISO study - that is, for each star in common between the two lists, we can derive individual filter factors that equalise both narrow band pairs of temperatures. An average is then taken of all the factors found in this way to apply to the new data. Such factors will constrain the ISO temperatures to fit the scale of the original narrow band IRFM temperatures. This method has proved very useful for assessment purposes only, and its results confirm the more direct integrations used for the various wider band ESO and TCS data. Temperatures found using individual filters are consistent to within about one per cent. Final temperatures have been derived by averaging those found with available filters, excluding J filters whenever practicable.

2.5. Determination of integrated flux

To determine integrated stellar fluxes for the ISO calibration stars, designated FLUX, the techniques described by Blackwell et al. (1990, 1991) have been followed. An interstellar extinction correction was applied as described above. The final results, expressed in units of , and corrected for interstellar extinction, are included in Table 1 (click here).

We relate the measured integrated fluxes, to values of (B-V)₀, (B2-V1)₀, (b-y)₀ and (V-K)₀, both as a check and as a tool for deriving fluxes in other circumstances where only such photometric quantities are available. With this in mind, Blackwell & Petford (1991) have shown that a reasonably smooth relation exists between the quantity , denoted the reduced flux RFLUX, and polynomials in (B-V) and (V-K), with all quantities corrected for interstellar extinction. In deriving such polynomial relations in the present work we have discarded the apparently anomalous results for five stars, HD 10700, HD 20794, HD 130163, HD 209100 and HD 216956.

Table 2 (click here) summarises polynomial relations of the form
RFLUX = A+Bx+Cx²+Dx³ where x is , , or derived for all stars in Table 1 (click here) (excepting those with a small value of [Fe/H]). In the case of , only stars observed by Johnson et al. (1966) have been used. The table includes standard deviations for the differences between observed and calculated values of RFLUX. These are reasonably small, but as mentioned above, a closer relationship cannot be expected because of the probable presence of unresolved binaries and metallicity effects as yet unaccounted for. Separate polynomials are given for Classes V, IV and III. Use of the extinction model of Arenou et al. (1992) yields a small increase in dispersion over that found using A_V = 0.8 mag/kpc. The effect of metallicity may be included in the calculation of RFLUX by multiplying the appropriate polynomial given in Table 2 (click here) by the factor . The importance of metallicity has been stressed by Alonso et al. (1996a). However, as the derived temperatures depend on the fourth root of the integrated flux, the effect is relatively small. Figure 1 (click here) shows the relation between RFLUX and for Class III stars of small metallicity; the standard deviation about the regression line is 4.3 per cent.

  
Figure 1: Plot of reduced integrated flux, RFLUX, for Class III stars of known small metallicity against . RFLUX has been has been corrected for interstellar extinction; the standard deviation about the regression line is 4.3 per cent

   

HD FLUX TEMP S PE HD FLUX TEMP S PE HD FLUX TEMP S PE

123 1.140E-10 5601 A 0.9 18411 3.636E-10 8558 A 0.9 45320 1.247E-10 8785 A 0.7

693 2.883E-10 6143 B 0.8 18702 1.759E-11 5268 A 0.9 45701 7.286E-11 5865 B 1.0

787 4.438E-10 4181 B 1.2 18978 6.080E-10 7855 B 0.9 46251 7.392E-11 9045 A 0.6

1368 7.820E-12 5887 A 0.9 19066 1.038E-10 4900 A 0.9 47174 5.186E-10 4394 A 1.0

1581 5.468E-10 5867 B 0.5 19373 6.372E-10 5981 A 0.6 47205 9.172E-10 4773 B 0.9

1835 7.590E-11 5713 B 2.0 19476 9.890E-10 5018 A 1.2 47442 7.190E-10 4633 A 0.9

2151 2.019E-09 5710 B 0.5 19656 5.296E-10 4714 A 0.9 49293 5.957E-10 4653 A 0.9

2262 6.688E-10 7882 B 0.8 20630 3.217E-10 5713 B 1.0 49933 1.279E-10 6484 A 0.7

2811 3.013E-11 8317 B 0.9 20766 1.703E-10 5770 B 1.5 50241 1.222E-09 7372 B 0.9

3443 1.743E-10 5240 A 0.7 20794 5.720E-10 5420 B 0.7 50522 5.687E-10 5077 A 0.9

3627 2.134E-09 4335 A 0.7 21120 1.117E-09 5031 A 0.9 53705 1.659E-10 5753 B 0.9

3628 3.255E-11 5673 A 0.9 21543 1.443E-11 5650 A 0.9 53706 5.591E-11 5325 B 1.0

3919 5.415E-10 5100 B 1.2 22484 5.125E-10 5944 B 0.5 53811 2.804E-10 8203 B 0.9

4128 5.168E-10 4853 B 0.9 22879 5.766E-11 5762 A 0.7 54810 3.906E-10 4758 B 0.9

5448 7.253E-10 7981 A 0.9 23763 4.948E-11 8441 A 0.9 56169 2.640E-10 8216 A 0.5

5516 5.588E-10 4970 A 0.9 24160 6.912E-10 5089 B 0.9 56405 1.774E-10 8721 B 1.0

6582 2.504E-10 5292 A 0.5 24341 2.107E-11 5462 A 0.9 56513 1.714E-11 5642 A 0.9

6595 1.497E-09 5116 B 0.9 24849 3.848E-12 6483 B 1.2 58207 1.073E-09 4766 A 0.8

6619 7.004E-11 8750 B 0.9 25329 1.377E-11 4834 A 0.5 58946 5.282E-10 6821 A 1.2

6660 1.763E-11 4547 A 0.9 25532 1.800E-11 5333 A 0.9 59294 6.307E-10 4482 A 0.9

6755 2.737E-11 5127 A 2.0 25604 6.439E-10 4799 A 1.2 59967 6.020E-11 5732 B 0.9

6961 4.747E-10 7998 A 0.9 26612 2.760E-10 6944 B 0.9 59984 1.177E-10 5896 A 0.6

7424 2.732E-12 5648 B 1.0 26756 1.244E-11 5617 A 0.9 60298 3.115E-11 5780 A 0.9

8799 2.938E-10 6520 A 1.2 26965 5.353E-10 5161 A 0.9 60778 7.310E-12 8370 B 0.7

9138 6.421E-10 4063 B 0.7 26967 1.091E-09 4644 B 0.9 61110 2.832E-10 6535 A 0.6

9362 9.174E-10 4840 B 0.9 27697 1.014E-09 4928 A 0.9 61935 9.324E-10 4814 B 0.9

9562 1.366E-10 5791 B 0.9 27741 1.392E-11 5765 A 0.9 62044 7.555E-10 4585 A 0.9

9826 5.958E-10 6136 A 0.5 27819 3.103E-10 8037 A 0.6 62509 1.047E-08 4837 A 0.6

9927 1.610E-09 4360 A 0.9 28100 4.488E-10 4882 A 0.9 64090 1.388E-11 5313 A 0.6

10126 2.356E-11 5538 A 0.9 28305 1.280E-09 4911 A 0.7 64096 2.354E-10 5771 A 0.7

10476 2.442E-10 5223 A 1.2 29291 9.828E-10 5015 B 0.7 64606 3.279E-11 5109 A 0.5

10697 8.748E-11 5612 A 0.9 29310 2.738E-11 5781 A 0.9 65430 2.605E-11 5127 A 0.9

10700 1.162E-09 5337 B 0.9 29388 5.082E-10 8282 A 0.9 65583 4.754E-11 5233 A 0.5

10800 1.215E-10 5835 B 0.9 30562 1.337E-10 5843 A 0.7 69897 2.320E-10 6217 A 0.5

11353 1.215E-09 4685 B 0.9 30652 1.378E-09 6380 B 0.6 71155 8.670E-10 9663 B 0.9

11443 1.096E-09 6321 A 0.9 31966 5.879E-11 5696 A 0.8 73108 5.947E-10 4524 A 0.7

11946 2.426E-10 9681 A 0.9 33276 3.127E-10 7249 A 1.2 73524 6.492E-11 5860 B 0.9

12311 1.797E-09 7165 B 0.9 34411 3.520E-10 5848 A 0.5 73665 9.254E-11 5022 A 0.9

13041 3.152E-10 8242 A 0.9 36283 1.065E-11 5616 A 1.0 74918 6.118E-10 5105 B 0.9

13201 7.113E-11 6357 A 0.5 37160 8.162E-10 4701 A 0.7 76932 1.282E-10 5719 A 0.6

13403 4.530E-11 5577 A 0.5 37394 9.871E-11 5179 A 0.5 78004 1.280E-09 4588 B 0.9

13783 1.375E-11 5527 A 0.7 37507 3.131E-10 8102 A 0.9 79917 3.988E-10 4675 B 0.9

13836 1.650E-11 5561 A 0.9 38393 9.446E-10 6210 B 0.5 81809 1.988E-10 5619 A 0.6

13974 3.158E-10 5594 A 0.6 38656 5.131E-10 4898 A 0.9 84937 1.273E-11 6202 A 1.2

14770 2.812E-10 4951 A 0.9 38858 1.129E-10 5669 B 0.9 85444 7.313E-10 5085 B 0.9

15008 6.533E-10 8936 B 0.9 39060 7.258E-10 8045 B 1.2 87140 8.789E-12 5172 A 2.0

15189 5.256E-12 6450 B 1.5 40035 1.099E-09 4764 A 0.9 88371 1.229E-11 5641 A 0.9

15798 3.305E-10 6331 A 0.9 40136 8.185E-10 7006 B 0.7 88742 7.552E-11 5861 B 0.8

16031 3.453E-12 6094 B 0.7 40832 8.375E-11 6489 A 0.9 89010 1.140E-10 5686 A 0.5

16160 1.725E-10 4759 A 0.5 43039 6.709E-10 4737 A 0.8 89125 1.249E-10 6028 A 0.6

16397 3.147E-11 5762 A 0.9 43147 7.229E-12 5158 A 0.9 90508 7.320E-11 5721 A 0.6

16815 8.202E-10 4766 B 0.5 44007 2.300E-11 4910 A 0.9 91324 2.930E-10 6124 B 0.7

17652 5.762E-10 4844 B 0.9 44420 2.533E-11 5804 A 1.0 92764 7.154E-12 8019 A 0.9

17674 2.586E-11 5875 A 0.9 44594 6.263E-11 5741 B 0.7 93702 2.140E-10 8878 A 0.9

 17824 3.968E-10 5063 B 0.9  45184 7.791E-11 5790 B 0.9  93813 2.510E-09 4431 B 0.9

 

HD FLUX TEMP S PE HD FLUX TEMP S PE HD FLUX TEMP S PE

94028 1.399E-11 5998 A 0.8 120136 4.009E-10 6424 A 0.9 144284 6.497E-10 6138 A 0.5

94510 1.012E-09 4938 B 0.9 120452 3.685E-10 4740 A 0.9 144579 6.505E-11 5309 A 0.9

94890 5.033E-10 4837 B 0.9 120787 1.459E-10 4936 A 0.9 146686 8.798E-10 4766 B 0.9

95370 4.608E-10 8217 B 0.9 121131 1.414E-11 5131 A 0.9 146791 1.694E-09 4882 A 0.9

95934 1.009E-10 7966 A 0.9 121474 4.867E-10 4694 B 0.9 147513 1.887E-10 5679 B 0.9

96566 4.786E-10 4913 B 0.9 123977 9.752E-11 4845 A 0.9 147547 7.687E-10 7125 A 0.5

96574 3.189E-11 6115 A 1.0 124850 6.132E-10 6168 A 0.9 148387 2.494E-09 5007 A 0.5

96833 2.359E-09 4650 A 0.9 125161 3.190E-10 7792 A 0.9 148786 6.159E-10 5106 B 0.9

97503 1.452E-11 4351 A 0.9 125454 3.193E-10 4845 A 0.9 148816 3.352E-11 5833 A 0.9

97916 5.699E-12 6409 A 0.6 126053 8.609E-11 5635 B 0.9 148856 2.406E-09 4983 A 0.9

98562 8.687E-12 5883 A 1.0 126681 5.457E-12 5558 A 1.0 149414 4.688E-13 5048 A 0.8

99747 1.184E-10 6547 A 1.0 127243 1.946E-10 5020 A 0.9 150997 1.274E-09 4918 A 0.7

100407 1.228E-09 5058 B 0.9 127665 1.663E-09 4220 A 0.9 151680 4.834E-09 4489 B 0.9

101206 1.996E-11 4576 A 0.9 128167 4.087E-10 6737 A 0.5 152156 4.413E-12 5017 A 0.8

101606 1.323E-10 6193 A 0.5 128429 8.659E-11 6336 A 0.5 152306 5.255E-11 4976 A 0.9

102249 9.013E-10 7908 B 0.9 128959 6.203E-12 5622 A 0.9 152311 1.273E-10 5588 A 0.8

102365 3.022E-10 5538 B 0.5 129502 7.164E-10 6642 B 0.9 153312 1.143E-10 4752 A 0.9

102634 9.137E-11 6317 A 0.6 129685 3.155E-10 9089 B 0.9 154363 3.809E-11 4340 A 0.9

102870 9.590E-10 6124 A 0.5 129858 1.508E-10 8968 B 0.9 155125 3.341E-09 8690 A 0.9

103095 8.340E-11 5054 A 0.5 130163 6.180E-11 9720 B 0.5 156026 1.288E-10 4377 A 0.6

103912 1.608E-11 5048 A 0.9 130871 8.062E-12 4785 A 0.9 156164 1.478E-09 8364 A 1.2

104076 1.425E-10 5884 A 0.9 130948 1.205E-10 5995 A 0.6 156277 5.387E-10 4499 B 0.9

104381 4.844E-11 8606 A 0.9 131977 2.011E-10 4609 A 0.9 157089 4.574E-11 5732 A 0.8

104979 7.408E-10 4903 A 0.9 132052 4.007E-10 6980 A 0.9 157740 1.460E-10 8758 A 1.0

105452 6.172E-10 6875 B 0.9 132142 2.417E-11 5143 A 0.9 157950 3.813E-10 6588 A 1.0

105755 1.038E-11 5784 A 0.7 132475 1.109E-11 5677 A 0.9 158226 1.128E-11 5823 A 1.0

106516 9.432E-11 6233 A 0.8 133208 1.263E-09 4997 A 0.7 158485 6.857E-11 8318 A 0.9

107213 7.582E-11 6317 A 0.6 134083 2.698E-10 6567 A 0.6 159222 6.553E-11 5708 A 0.8

107259 8.167E-10 8950 A 0.9 134169 2.329E-11 5817 A 0.7 159561 3.665E-09 7883 A 0.8

107582 1.427E-11 5616 A 0.9 134439 7.962E-12 5007 A 0.8 160693 1.235E-11 5752 A 0.8

108110 1.435E-10 4580 A 0.9 134505 1.384E-09 5058 B 0.9 161096 3.010E-09 4601 A 0.6

108153 1.088E-11 4814 A 0.9 134987 7.413E-11 5591 A 1.0 161198 3.106E-11 5268 A 1.0

108255 3.218E-10 5011 A 1.0 135153 3.350E-10 6705 B 0.9 161797 1.222E-09 5496 A 0.6

108847 8.023E-12 4796 A 0.9 135379 6.283E-10 8565 B 1.0 161892 2.171E-09 4471 B 0.9

108954 8.748E-11 6068 A 1.0 135502 2.313E-10 8926 A 1.2 163588 1.281E-09 4495 A 0.9

109787 7.695E-10 8673 B 0.9 135722 1.360E-09 4810 A 0.7 163772 8.089E-11 8284 A 0.9

110458 4.997E-10 4728 B 0.9 136274 1.965E-11 5331 A 0.9 163810 4.112E-12 5595 A 0.9

111397 1.590E-10 9216 A 0.9 136352 1.519E-10 5614 B 0.7 163917 1.536E-09 4849 B 0.9

111721 2.570E-11 5165 A 0.5 138290 6.044E-11 6858 A 0.6 163993 1.032E-09 5011 A 0.7

111812 3.098E-10 5747 A 0.9 138716 4.989E-10 4801 B 0.8 164507 9.068E-11 5560 A 0.9

111980 1.304E-11 5667 A 0.8 139590 2.712E-11 6116 A 0.9 165135 2.291E-09 4773 B 1.2

111996 6.453E-12 4571 A 0.9 139663 4.555E-10 4332 B 0.9 165341 7.992E-10 4983 A 0.7

112164 1.213E-10 5916 B 0.7 139798 1.270E-10 6748 A 0.5 166620 9.115E-11 4995 A 0.8

113101 7.572E-12 5481 A 0.9 140301 1.169E-10 4661 A 0.9 166640 1.889E-10 5079 A 1.2

113314 3.426E-10 9220 B 0.9 140573 3.353E-09 4558 A 0.6 167858 5.881E-11 7050 A 0.6

114606 9.197E-12 5623 A 0.9 141003 9.186E-10 8542 A 0.9 168009 8.352E-11 5833 A 0.9

114710 5.263E-10 5959 A 0.5 141352 2.788E-11 6390 A 1.2 169414 1.206E-09 4460 A 0.7

114762 3.269E-11 5904 A 0.9 141653 2.457E-10 8952 A 0.9 170845 4.809E-10 4907 B 1.2

114837 2.852E-10 6143 B 0.9 141714 4.152E-10 5247 A 0.9 171391 2.879E-10 5116 B 1.2

115383 2.201E-10 5989 B 0.7 141891 1.914E-09 7112 B 0.9 172310 1.236E-11 5441 A 0.9

115617 3.592E-10 5430 B 0.7 142091 4.225E-10 4731 A 0.9 172323 1.605E-11 5814 A 0.9

115892 2.247E-09 9102 B 0.9 142373 3.864E-10 5745 A 0.6 173667 5.324E-10 6329 A 0.7

116842 6.443E-10 8008 A 0.9 142575 1.019E-11 6623 A 0.9 175190 4.602E-10 4193 B 0.9

117176 2.930E-10 5482 A 0.6 143546 4.580E-10 5079 B 0.9 175541 2.172E-11 4979 A 0.9

118098 1.166E-09 8296 B 0.9 143761 1.875E-10 5726 A 0.5 176411 8.600E-10 4722 A 0.9

 

HD FLUX TEMP S PE HD FLUX TEMP S PE HD FLUX TEMP S PE

176524 4.588E-10 4555 A 0.9 194598 1.242E-11 5926 A 0.6 211388 1.124E-09 4140 A 1.2

176638 3.922E-10 9710 B 0.9 195987 4.836E-11 5059 A 0.9 211391 6.940E-10 4985 B 0.7

178253 6.352E-10 8869 B 0.9 196171 1.959E-09 4855 B 0.9 211476 4.168E-11 5840 A 0.5

178345 9.750E-10 4575 B 1.2 197076 7.196E-11 5774 A 0.6 212330 2.079E-10 5613 B 0.9

178428 1.035E-10 5608 A 0.5 197692 5.637E-10 6517 B 0.6 212943 4.531E-10 4656 A 0.6

179626 6.201E-12 5761 A 0.9 197989 3.600E-09 4732 A 0.6 213009 8.858E-10 4884 B 0.9

180711 2.007E-09 4793 A 1.2 198001 9.357E-10 9227 B 0.9 214059 1.474E-11 5553 A 0.9

181276 9.826E-10 4997 A 0.9 201381 5.118E-10 5093 B 0.9 214868 7.600E-10 4239 A 1.2

181321 7.007E-11 5710 B 0.9 201889 4.414E-11 5621 A 0.6 214994 3.720E-10 9443 A 0.9

181597 1.210E-10 4663 A 1.2 201891 1.709E-11 5918 A 0.7 215182 2.092E-09 5104 A 0.9

181623 4.950E-10 6778 B 0.9 203387 6.103E-10 5105 B 0.9 215648 5.571E-10 6222 B 0.9

181655 8.369E-11 5676 A 0.9 203504 8.644E-10 4687 A 0.9 215721 2.663E-10 4942 B 0.9

182572 2.447E-10 5528 A 0.5 203608 5.395E-10 6073 B 0.7 216131 1.269E-09 4981 A 0.5

182807 8.929E-11 6103 A 0.6 204121 9.207E-11 6411 B 0.5 216627 1.322E-09 8571 B 0.9

184492 3.580E-10 4694 B 0.9 203850 1.198E-11 4780 B 0.9 216637 1.439E-10 4446 A 0.9

184499 6.227E-11 5773 A 0.6 204577 6.532E-11 6726 B 0.9 216735 3.393E-10 9528 A 0.7

184960 1.217E-10 6220 A 0.7 204814 2.030E-11 5374 A 0.9 216777 1.752E-11 5634 A 0.9

185395 4.008E-10 6672 A 0.7 204867 2.040E-09 5474 B 0.5 216956 9.033E-09 8622 B 1.0

185758 4.986E-10 5415 A 0.7 205512 4.091E-10 4696 A 0.6 217877 5.731E-11 6011 B 1.0

188114 8.675E-10 4683 B 0.9 206453 4.104E-10 5093 B 0.9 219080 3.847E-10 7096 A 0.9

188510 8.375E-12 5636 A 0.9 209100 4.998E-10 4577 B 0.8 219891 6.349E-11 7856 A 1.2

188512 1.024E-09 4990 A 0.6 209750 2.085E-09 5206 B 0.6 219953 9.256E-12 5046 A 0.9

189558 2.309E-11 5666 A 0.7 209993 9.601E-11 8617 A 0.7 220321 1.022E-09 4602 B 0.9

190299 2.757E-10 4163 A 1.2 210027 8.020E-10 6288 A 1.0 220594 6.996E-10 4733 B 0.9

190360 1.427E-10 5580 A 0.5 210049 4.423E-10 8847 B 0.9 220657 4.671E-10 5942 A 0.7

190404 3.975E-11 5015 A 0.5 210144 2.285E-11 5403 A 0.9 220957 9.539E-11 4904 A 0.9

190571 3.530E-11 4987 A 0.9 210459 4.825E-10 6249 A 0.9 221115 4.930E-10 4985 A 0.9

191277 2.912E-10 4523 A 0.9 210460 9.820E-10 5399 A 0.5 221914 2.537E-11 5574 A 0.9

192947 1.179E-09 4933 B 0.5 210918 8.884E-11 5658 B 0.9 222603 3.992E-10 7766 A 0.9

194013 2.680E-10 4895 B 0.9 211006 1.828E-10 4525 A 0.9 222935 1.375E-11 5015 A 0.9

   

A B C D Class V

(B-V) 296.66 -254.06 377.61 -54.72 5.5

(B2-V1) 263.27 -130.17 411.37 -1.10 7.0

(V-K) 257.31 -3.95 -24.26 16.81 4.5

(b-y) 290.60 -397.69 905.00 -71.96 5.6 Class IV

(B-V) 315.90 -180.62 112.14 90.01 4.4

(B2-V1) 280.22 -177.64 409.75 -0.82 3.0

(b-y) 312.74 -327.63 557.04 4.8 Class III

(B-V) 260.40 -72.82 90.77 63.56 4.3

(B2-V1) 250.49 5.84 54.86 210.10 4.9

(V-K) 248.56 -2.57 -4.88 10.23 2.9

(b-y) 317.38 -450.61 909.93 -179.79 8.8

Table 2: Coefficients in polynomial representations of RFLUX in terms of photometric variables (B-V), (B2-V1), (V-K) and (b-y), all corrected for interstellar extinction; is the percentage standard deviation about the regression line. See text for correction for metallicity [Fe/H]