CDROM/PASP/V108/P0313 Empirical Stellar Flux Scales (Hall 1996) ================================================================================ On the Determination of Empirical Stellar Flux Scales Jeffrey C. Hall <1995, PASP, 108, 313> =1995PASP..108..313H ================================================================================ Abstract: Several studies have appeared in the literature describing methods for deriving stellar continuum fluxes as simple functions of Johnson color indices. In previous papers, we have used similar relations to derive Ca II H & K line core fluxes for dwarf stars on Lowell Observatory's Solar-Stellar Spectrograph (SSS) program. Our desire is to present our data, and complementary data from the Mt. Wilson and National Solar Observatory stellar and solar programs, in terms of physical fluxes. However, our existing relations break down for mid-K and later stars and for giant stars, which form an important element of our target list. In this work I have used a broader range of spectrophotometry and angular diameters than in our previous work to derive empirical flux scales for spectral types A to early M, luminosity classes I to V, and for four color indices, Johnson B-V, V-R, R-I, and Stromgren b-y. In this paper I describe the methods I used and present the derived flux scales. I compare the results with those from earlier studies and present examples of the use of the flux scales. The data and results are available on the World Wide Web. File Summary: -------------------------------------------------------------------------------- File Name Lrecl Records Explanations -------------------------------------------------------------------------------- table4.dat 63 26 Empirical flux scales table5.dat 67 146 Table of references table6.dat 64 146 Stellar properties blanket.dat 89 155 Line blanketing coefficients -------------------------------------------------------------------------------- Byte-by-byte Description of file: table4.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1-12 A12 --- Bandpass *Bandpasses the coefficents apply to 13-14 2X --- --- Blank 15-17 A3 --- CI Color index to which C0,C1 apply to 18-24 F7.3 --- C0 *Zeroth-order coefficient of flux scale 25-32 F8.3 --- C1 *First-order coefficient of flux scale 33-38 F6.3 dex E_d Error in dex of flux scale relation 39-41 I3 % E_p Error in percent of flux scale relation 42-48 F7.2 mag CR_b *Blue end of CI range C0,C1 apply to 49-54 F6.2 mag CR_r *Red end of CI range C0,C1 apply to 55-57 3X --- --- Blank 58-63 A6 --- LC Luminosity classes C0,C1 apply to -------------------------------------------------------------------------------- Notes for file: table4.dat -------------------------------------------------------------------------------- Bandpass: The continuum flux of a star of color index X in one of the three bandpasses given in the table is: F(cont) = 10.^(C0 + (C1 * X)) +/- [E_d(dex), or ~E_p %], with units of ergs/cm2/s/A. Any pair of coefficients [C0, C1] applies only to the indicated luminosity classes, and only to the indicated color range. Due to rapidly decreasing numbers of data points at the extrema of the color range (resulting from the difficulty of doing spectrophotometry at those extrema, particularly for K and M stars), the fits degrade rapidly beyond the indicated ranges. C0, C1: These are the coefficients to be entered in a relation of the form log (F(lambda) = C0 + C1(CI), C0 is the zeroth-order coefficient, C1 is the first-order coefficient, and CI is the color index corresponding to those coefficients. CR_b, CR_r: These fields indicate the range of the particular color index for which a pair of flux-scale coefficients may be used. A flux-scale relation should never be applied outside these limits, because of the many quantities that go into deriving the stellar continuum fluxes, as well as the rapidly changing and uncertain nature of these quantities at the color index extrema (e.g.blanketing). -------------------------------------------------------------------------------- Byte-by-byte Description of file: table5.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 6 I6 --- HD Henry Draper Catalogue number 7 1X --- --- Blank 8-19 A12 --- Name Star name 20-44 A25 --- r_Sp *Spectrophotometric references 45-50 A6 --- r_D *Reference for star's angular diameter 51 1X --- --- Blank 52-63 A12 --- r_Bl *Reference for blanketing coefficients 64-67 A4 --- r_b-y *Reference for Stromgren b-y index -------------------------------------------------------------------------------- Notes for file: table5.dat -------------------------------------------------------------------------------- r_Sp, r_D, r_Bl, r_b-y: r_Sp is the spectrophotometric references for the star. The main reference used in making the flux scales is listed first. Other references are listed in parentheses, "()". Standard stars of Taylor (1984) and Hayes & Latham (1975) are listed in angle brackets, "<>". Abbreviations for all references are as follows (see printed paper for full references): B76 = Breger 1976; BEM78 = Barnes, Evans, & Moffett 1978; BL94 = Blackwell & Lynas-Gray 1994; BHNT67 = Baschek et al. 1967; BO65 = Baschek & Oke 1965; CB70 = Crawford & Barnes 1970; DP71 = Dickens & Penny 1971; HL75 = Hayes & Latham 1975; HM90 = Hauck & Mermilliod 1990; J66 = Jones 1966; KTK88 = Kharitonov et al. 1988; O67 = Oke 1967; OC66 = Oke & Conti 1966; O74 = Oinas 1974; R69 = Rodriguez 1969; S65 = Stromgren & Perry 1965; S71 = Stickland 1971; SPO71 = Schild, Peterson, & Oke 1971; T84 = Taylor 1984; vP76 = van Paradijs 1976; W65 = Willstrop 1965; W67 = Whiteoak 1967; WBSB62 = Wildey et al. 1962. -------------------------------------------------------------------------------- Byte-by-byte Description of file: table6.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 6 I6 --- HD Star's Henry Draper Catalogue number 7- 8 2X --- --- Blank 9-18 A10 --- Sp Spectral type and luminosity class 19-23 F5.2 mas D []?=0. Star's angular diameter 24-28 F5.2 mas e_D []?=0. Error in D 29-35 F7.2 mag V V magnitude 36-42 F7.2 mag B-V Johnson B-V color 43-49 F7.2 mag V-R []?=9. Johnson V-R color 50-56 F7.2 mag R-I []?=9. Johnson R-I color 57-64 F8.3 mag b-y []?=9. Stromgren b-y color -------------------------------------------------------------------------------- Byte-by-byte Description of file: blanket.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 4 I4 0.1nm Lambda *Central wavelength of bandpass 5-11 F7.4 --- C0 Zeroth-order polynomial coefficient 12-19 F8.4 --- C1 First-order polynomial coefficient 20-27 F8.4 --- C2 Second-order polynomial coefficient 28-36 F9.4 --- C3 Third-order polynomial coefficient 37-45 F9.4 --- C4 Fourth-order polynomial coefficient 46-52 F7.3 --- sigma Std. dev. of data points about the fit 53-58 F6.2 mag CR_b Bluest color index for the fit 59-64 F6.2 mag CR_r Reddest color index for the fit 65-68 A4 --- LC0 []?=no Luminosity class for C0 69-72 A4 --- LC1 []?=no Luminosity class for C1 73-76 A4 --- LC2 []?=no Luminosity class for C2 77-80 A4 --- LC3 []?=no Luminosity class for C3 81-84 A4 --- LC4 []?=no Luminosity class for C4 85-86 2X --- --- Blank 87-89 A3 --- CI Color index for coefficient -------------------------------------------------------------------------------- Notes for file: blanket.dat -------------------------------------------------------------------------------- Lambda: The central wavelength of a 50-A wide bandpass to which the coefficients in the same row are applicable. -------------------------------------------------------------------------------- ================================================================================ (End) Lee Brotzman [ADS] 07-May-1996