Table A7 'B-V-1950-Data-vsn-8' Annotated list of (B-V) and other colour measurements from 1942 - 1974, collected from the literature, resulting in subsection 9) "Table of the combined sequence of B-V measurements from 1942 - 1974", and in subsection 10) "Gyldenkerne's (1955ApJ...121...38G) 'intrinsic' B-V for E(B-V)=0.70." This document contains observations from the beginning of of photoelectric measurements and mentions different multicolour measurement systems. An area of uncertainty in using different colour systems is the transformation between systems, and the differences in influence of interstellar reddening. The hypergiant HR8752 was used as a reference standard, and not as a variable star, so that sometimes no mention is made of observation date. Also comparisons of colour data were referenced against the standard Morgan Keenan (MK) spectral classification as G0Ia. Oja (1963ArA.....3..273O) remarked "The star is probably variable". In the main paper we mention a correction to the standard MK specification by using data from a created 'time history' to find the correct MK classification from lists of colour and temperature data. The collected data is from various authors (Zsoldos 1986Obs...106..156Z; Fry & Aller 1975ApJS...29...55F; Luck 1975ApJ...202..743L; Parsons & Montemayor 1982ApJS...49..175P) and the ADS at Strasbourg and from the open literature. In the list below we use an incremental reference number as identifier and indicate Julian Day (JD), date, (uncertainty in days), Morgan Keenan (MK) classification, s-parameter (cf. Appendix Table C2). Early measurements for HR8752 refer to either Boss 5931 = BD+56o2923 = BS8752 = HD 217476. A table collects relevant data at the end of this section. We discuss also some Non-(B-V) measurements. In order to find the 'intrinsic' B-V, the reddening parameter E(B-V) has to be derived. Values in the literature vary from about 0.30 - 0.66. The published value of 0.82 by Johnson (1968, ch. 5, "Interstellar Extinction", in Stars and Stellar Systems, Vol. VII, "Nebulae and Interstellar Matter", Middlehurst, B.M., & Aller, L.H., editors, The University of Chicago Press., Chicago) is incorrect, but is found to be 0.70 when spectral type and (B-V) observation are synchronized in time (see above and main paper Section 3) which allows us to compare synchronous (B-V) and MK observations. In this paper we use Johnson B-V, but also other color systems if suitable interstellar reddening corrections can be applied. Some color systems are less sensitive to interstellar extiction than the Johnson B-V system, and need a smaller correction factor . Gyldenkerne uses a colour system with limited influence of reddening of ~16% of that of the B-V system. This explains the confusion when comparing the Gyldenkerne data (Zsoldos 1986Obs...106..156Z) with Johnson (B-V) observations. It turns out that the observed value is within 16% of the classical (B-V) reddening and is thus already very near to the 'intrinsic'or unreddened value. ------------------------------------------------------------------------------- -1) Measurements of Stebbins and Whitford (1945ApJ...102..318S) a) Observations with a six-color photometer in the summers of 1940-1944 given as U6-I6 below indicate a six-color photometry system. We add the column (B-R)6 and take as observation date 1942 July 15 (JD 2430556), with an uncertainty of 720 days. The visual magnitude is not contemporary with the photometric measurements. The (spectroscopic) absolute magnitude M is from Adams et al. (1935ApJ....81..187A). Early visual magnitudes are by Adams et al. (1921ApJ....53...13A, mvis=5.5), Adams & Joy (1919PASP....3..176A, Boss 5931 mvis=5.6), but no actual observation dates are given. We give estimates of date in Table A5. Zug (1931ApJ....73...26Z) and Lamla (1965, in Landolt-Boernstein, New Series, Volume 6/1, H.H. Voigt, editor Springer-Verlag., Berlin, section 5.2.6, p.334) give transforms from the (revised) Harvard photometric to the international photovisual system. HD 217476 spectrum m M | U6 V6 B6 G6 R6 I6 (V-B)6 Obs | (B-R)6 (HR 8752) cG3 5.48 -3.2 | +1.53 +0.67 +0.39 +0.01 -0.39 -0.90 +0.28 1 | +0.78 Spectrum, m , M are as given by Adams et al. (1935ApJ....81..187A) from the Henry Draper catalogue. b) Kron (1958PASP...70..561K) gives an overview of supergiants using Stebbins & Whitford (1945ApJ...102..318S). With Kron's (1958PASP...70..561K, Fig. 4) we estimate excesses E(R-I)6= 0.64+/-.02 and E(V-B)6=0.29+/-.02. For thermal locus, Kron mentions spectral type "f8". Kron mentions E(P-V)=1.78*E(V-B)6=0.53. c) Fernie (1972AJ.....77..150F) transforms the Stebbins & Whitford (1945ApJ...102..318S) observations to the Johnson UBVRI system, by intermediate use of 61 of the 139 stars in the list of UBVRI (Iriarte et al. 1965, Sky and Telescope, 30, 21) with average deviations f 0.085 in V and 0.031 in B-V. The data below are from Table II (Fernie 1972AJ.....77..150F) transformed to the Johnson system, but note that the used transform is only valid for unreddened data, and that spectral type and visual magnitude are not contemporary to the color observations. HD sp.T. V | U-B B-V V-R R-I E(B-V) 217476 G0 Ia 5.36 | 1.09 1.28 0.92 0.84 0.58 +- 0.085 | +-0.031 As date we take JD 2430556 (July 15, 1942), with an uncertainty of 700 days. d) Schmidt (1972ApJ...174..605S) finds E(V-B) = 0.66 from "results of the six-color photometry (Kron 1958PASP...70..561K) "the results of the six-color photometry (Kron 1958PASP...70..561K, using Fernie's [1967AJ.....72..442F] correction to the UBV system)," which depends on the measurements of Stebbins & Whitford (1945ApJ...102..318S). Schmidt needed the value to correct observations of the Paschen continuum slope m6335-m8205 for interstellar absorption, using E(B-V)/ E(m6335-m8205) = 1.23, and from comparison with models finds Theta_eff=1.002 with a sigma of 0.033. This corresponds to Teff=5030 +- 171 K, which we use in the main paper as one of the four extra temperature measurements in Section 3. ------------------------------------------------------------------------------ -2a) Measurements of Johnson (1955AnAp...18..292J, 1965ApJ...141..923J) for HD 217476, taken as G0 Ia standard of the MK system are given in table 2 of Johnson & Morgan (1953ApJ...117..313J) and in Table 3b of Johnson (1955AnAp...18..292J). The photometric observations were made by Johnson at the McDonald Observatory in the winter of 1950-1951 and the summer of 1951. Luck (1975ApJ...202..743L) gives 1951 as date. The total number of observations is 3. No. HD Name n eps V B-V U-B Sp 277 217476 HR 8752 3 9 4.99 +1.29 +1.00 G0 Ia accuracies +-.017 +-.009 +-.017 As date we take 1951 April 15 with an uncertainty of 135 days. -2b) Measurements of Johnson (1965ApJ...141..923J, Table 2, BS 8752) are given for variable star, J. D. 2438300.0 (27 Sept. 1963). We adopt an accuracy for V, B-V of 0.01 resp. 0.01. no. HD name Sp V U-V B-V V-R V-I V-J V-K V-L V-M V-N 96* 217476 BS 8752 G0 Ia 5.13 +2.88 +1.55 +1.17 +2.02 +2.61 +3.33 +3.59 - +4.18 -2c) Measurements by Johnson et al. (1966Lab.....4...99J) referenced in a publication by Zsoldos (1986Obs...106..156Z, Table II) are given. We adopt an accuracy for V and B-V of 0.005. V B-V U-B date JD 5.176 +1.535 +1.315 21 June 1964 2438568 5.106 +1.553 +1.339 02 July 1964 2438579 ------------------------------------------------------------------------------- -3) Gyldenkerne (1955ApJ...121...38G) made two measurements between september 1951 and summer 1953 in the author's S1-system in Sofienholm. The data (Gyldenkerne 1955ApJ...121...38G, 1958AnAp...21...26G; Stroemgren & Gyldenkerne 1955ApJ...121...43S) give a 'corrected' k-factor of k=0.414. The visual magnitude is m=5.5. Observations with system S1 were approximately from 1951 Sep. 26 to 1953 July 1 (Gyldenkerne 1958AnAp...21...26G, Table 3), so we take 1952 June 15 as observation date, with an uncertainty of 350 days. Stroemgren & Gyldenkerne (1955ApJ...121...43S) mention a probable error in B-V of +- 0.016. We try to find the intrinsic (B-V). k = .414 (+- .0092), n = .170 (+- .0061), g = .210 (+- .0078). k,0 = k + E(k) = k + E(k) /E(B-V) * E(B-V) E(k) /E(B-V)=0.118 (B-V) = +1.420 - 1.385 * k (Gyldenkerne 1955ApJ...121...38G, Eqn.2) (B-V)0 = (B-V)-{1.385*E(k) /E(B-V)*E(B-V)}=0.847 - E(B-V)*0.163=0.73 +-0.02, at second round =0.75 +-0.02, 3rd 0.76 +-.02, so second round is intermediate between low and high (E(B-V)= (0.49 - 0.76) with B-V~0.77-0.72 for Gyldenkerne ->B-V=0.75 +-.025. The relatively small amount of reddening explains why the observations of Gyldenkerne deviate from other B-V (reddened) observations because they are (in comparison with (B-V) observations) already 84 % dereddened and therefore give an approximation to within 16% of E(B-V) of the intrinsic color B-V. ------------------------------------------------------------------------------- -4a) Oja (1963ArA.....3..273O) made 4 observations in the years 1958-1960 with mean value: Julian Date +- mU +- CU +- p VU +- (B-V)J (B-V)U +- 2436751 500d 5.267 .011 0.520 .011 4 5.16 .010 1.29 1.39 .011 p=4 (measurements); the accuracies for B-V and for VU are given as estimates. The difference between (B-V)J (Johnson 1955AnAp...18..292J) and (B-V)U, and also between Johnson's (1954) V-magnitude of 4.99 m and VU V= 4.99 lead to Oja's remark "The differences in magnitude and colour cannot be explained by observational errors. The star is probably variable." (see introduction to this table). As date we take 1959 August 1 with an uncertainty of 500 days. ----------------------------------------------------------------------------- -4b) Ljunggren and Oja (1965ArA.....4..137L) observed with a new photometer in 1961 and give: Julian Date V +- B-V +- CU' +- 2437544.6 4.98 .014 +1.36 .011 -0.066 .013 2437621.3 5.08 .014 +1.38 .011 -0.050 .013 2437646.2 5.14 .014 +1.33 .011 -0.094 .013 2437544.6 5.20 .014 +1.32 .011 -0.103 .013 ------------------------------------------------------------------------------- -5) Sandage & Smith (1963ApJ...137.1057S) made an observation in July and September 1960 with new equipment including the use of a S20-surface cathode. Transforms from (b-v)20 and (u-b)20 colours to the Johnson, Morgan & Harris B-V, U-B values are given below. The accuracy of the B-V data is +- 0.05, for the U-B data is +- 0.07. The results for HR 8752 are from Sandage & Smith (1963ApJ...137.1057S, Table 1): JM no HD Star name Sp Type (U-B)20 (B-V)20 (v-r)20 d(U-B) n 277 217476 HR 8752 G0 Ia +1.06 +1.38 +1.05 ...... 1 B-V = 1.100 (+-.004)* (b-v)20 + 1.023 (+-.003) (loc. cit. Eqn 1) U-B = 1.015 (+-.003)* (b-v)20 - 1.575 (+-.006) (loc. cit. Eqn 2) Although the effective wavelengths for u, b, v are slightly different from those of the U, B, V system, Sandage and Smith (1963ApJ...137.1057S) mention that "Our complete data taken together states that .. .. In any case the (B-V)20 and (U-B)20 colors are sufficiently close to B-V and U-B that they are used without further distinction in the remainder of the text and diagrams". We therefore use these data as B-V data. As date we take 1960 July 15 +- 45 days. ------------------------------------------------------------------------------- -6) Measurements by Kraft & Hiltner (1961ApJ...134..850K) were made with McDonald 82-inch reflector in October 1960. Considering other observations we estimate an accuracy for V, B-V of 0.02 and 0.02 respectively. V B-V U-B date 5.13 +1.46 +1.14 October 1960 As date we take JD 2437223 (October 15, 1960) with an uncertainty of 15 days. ------------------------------------------------------------------------------- -7) Measurements by Eggen (1968) indicate that the star is variable (V) and that two measurements were made (column N). The observation date is given as 1962-1964 (Luck 1975ApJ...202..743L; Zsoldos 1986Obs...106..156Z). We estimate an accuracy for V, B-V of 0.02 and 0.02 respectively. Star Rem V B-V U-B N HD 217476 V 5.12 +1.42 +1.14 2 As date we take 1963 July 1, with an uncertainty of 545 days. ------------------------------------------------------------------------------- -8) Measurement by Luck (1975ApJ...202..743L) is derived from spectral scans for November 1974, using the method of isophotal wavelengths (MacFarlane 1969PASP...81...46M). V B-V date ---- +1.73 +-0.06 November 1974 As date we take 1974 November 16 with an uncertainty of 15 days. ------------------------------------------------------------------------------- -9) The combined sequence of B-V measurements from 1942 - 1974, sorted in (mean) time, followed by the 'intrinsic' or (B-V)0 value of Gyldenkerne (1955ApJ...121...38G), which was derived in the course of this work, for E(B-V)= 0.70. The other B-V values are observed values, that have to be dereddened to obtain 'intrinsic' values. No. JD +- days date V +- B-V +- Reference ------------------------------------------------------------------------------- 1: 2430556 720 15-07-1942 ---- ---- 1.28 .031 Stebbins & Whitford (1945ApJ...102..318S) 2a: 2433752 135 15-04-1951 4.99 .017 1.29 .009 Johnson (1955AnAp...18..292J) 4a: 2436751 365 01-08-1959 5.16 .010 1.39 .011 Oja (1963ArA.....3..273O) 5: 2437131 45 15-07-1960 ---- ---- 1.38 .005 Sandage & Smith (1963ApJ...137.1057S) 6: 2437223 15 15-10-1960 5.13 .02 1.46 .02 Kraft & Hiltner (1961ApJ...134..850K) 4b: 2437544.6 02-09-1961 4.98 .023 1.36 .024 Ljungren & Oja (1965ArA.....4..137L) 4b: 2437621.3 17-11-1961 5.08 .023 1.38 .024 Ljungren & Oja (1965ArA.....4..137L) 4b: 2437646.2 12-12-1961 5.14 .023 1.33 .024 Ljungren & Oja (1965ArA.....4..137L) 4b: 2437647.2 13-12-1961 5.20 .023 1.32 .024 Ljungren & Oja (1965ArA.....4..137L) 7: 2438212 550 01-07-1963 5.12 .02 1.42 .02 Eggen (1968) 2b: 2438300 27-09-1963 5.13 .01 1.55 .01 Johnson (1965ApJ...141..923J) 2c: 2438568 16-06-1964 5.176 .005 1.535 .005 Johnson et al. (1966Lab.....4...99J) 2c: 2438579 02-07-1964 5.106 .005 1.553 .005 (ref. Zsoldos 1986Obs...106..156Z) 8: 2442368 15 16-11-1974 ---- ---- 1.73 .06 Luck (1975ApJ...202..743L) ----+-----------+----+----------+---------------------------------------------- -10)Seperately: Gyldenkerne's (1955ApJ...121...38G) 'intrinsic' B-V for E(B-V)=0.70. No. JD +- days date [E(B-V)=0.70] (B-V)0 +- Reference ------------------------------------------------------------------------------- 3a: 2434179 300 15-06-1952 0.73 .016 Gyldenkerne (1955ApJ...121...38G) -------------------------------------------------------------------------------- (end)