B8V Garrison94 does not list a B8V anchor standard, but MK73 lists 18 Tau as the B8V dagger standard. 18 Tau appears to be the best B8V standard. GarrisonGray94 used HR 9050 = HD 224112 as is low-vsini B8V standard and 18 Tau as its high-vsini B8Vn standard. Inexplicably, the B8V standards changed completely between MK43 and JM53. MK43 standard: bet Per - B8V bet Lib - B8V alf Leo - B8V bet CMi - B8V JM53 standard: 18 Tau - B8V 21 Tau - B8V zet Peg - B8V iot And - B8V Garrison67 standard: 18 Tau - B8V bet Lib - B8V Lesh68 standard: 18 Tau - B8V Cowley69 standards: 18 Tau - B8V 21 Tau - B8V Hiltner69 standard: 18 Tau - B8V Cowley72 standards: 18 Tau - B8V 21 Tau - B8V iot And - B8V bet Cyg - B8V zet Peg - B8V MK73 standard: 18 Tau - B8V (dagger standard) Houk75 standard: 18 Tau - B8V (primary standard) Garrison77 standard: 18 Tau - B8V GarrisonGray94 standard: 18 Tau - B8Vn (high vsini) HR 9050 - B8V (low vsini) WiegertGarrison98 stan.: HD 142315 - B8V GrayAtlas standard: bet Per - B8V GrayNstars standard: bet Per - B8V Skiff08 lists only one B8V standard (HD 23324 = 18 Tau; MK73) All Q-method dereddenings in this file have been updated with the most recent calibration (Oct 2011). B-V(B8V) = -0.05 ; Cowley70(N=20*s) B-V(B8V) = -0.083 ; Crawford76 B-V(B8V) = -0.083 ; sec. stan. 21 Tau (EEM dereddened via Q-method) B-V(B8V) = -0.09 ; JohnsonMorgan53, Morgan53, Johnson63, Johnson66 B-V(B8V) = -0.099 ; EEM 9 d<75pc B8V Hipparco stars B-V(B8V) = -0.10 ; Bessell79 B-V(B8V) = -0.104 ; sec. stan. HR 9050 (EEM dereddened via Q-method) B-V(B8V) = -0.106 ; EEM dereddened N=99 HIP B8V stars (Q-method,E(B-V)<0.1) B-V(B8V) = -0.109 ; tert. stan. bet Lib (unreddened) B-V(B8V) = -0.11 ; Garrison67, Fitzgerald70, Morgan71, SchmidtKaler82 B-V(B8V) = -0.111 ; prim. stan. 18 Tau (EEM dereddened via Q-method) B-V(B8V) = -0.121 ; sec. stan. bet Per (EEM dereddened) U-B(B8V) = -0.265 ; sec. stan. 21 Tau (EEM dereddened via Q-method) U-B(B8V) = -0.31 ; Cowley70(N=20*s) U-B(B8V) = -0.30 ; Bessell98, Johnson63, Johnson66 U-B(B8V) = -0.34 ; Schmidt-Kaler82 U-B(B8V) = -0.354 ; sec. stan. HR 9050 (EEM dereddened via Q-method) U-B(B8V) = -0.36 ; Fitzgerald70 U-B(B8V) = -0.364 ; EEM dereddened N=99 B8V HIP stars (Q-method,E(B-V)<0.1) U-B(B8V) = -0.365 ; ter. stan. beta Lib (unreddened) U-B(B8V) = -0.368 ; (B-V) = -0.109 => (U-B)o using EEM relation U-B(B8V) = -0.389 ; pri. stan. 18 Tau (EEM dereddened via Q-method) => adopt (U-B)(B8V) = -0.364 *** [updated 9/26/2019] => adopt (B-V)(B8V) = -0.109 => adopt Q(B8V) = -0.286 (=(U-B)-0.72*(B-V) = -0.364 - 0.72*-0.109) => adopt (V-I)(B8V) = -0.108 => adopt (V-R)(B8V) = -0.048 => adopt (R-I)(B8V) = -0.060 => adopt (V-J)(B8V) = -0.190 => adopt (V-H)(B8V) = -0.257 => adopt (V-Ks)(B8V) = -0.254 => adopt (H-Ks)(B8V) = 0.003 => adopt (J-H)(B8V) = -0.067 (Ks-W1)(B8V) = 0.033 ; EEM trend for d<30pc for B-V=-0.109 => adopt (Ks-W1)(B8V) = 0.033 [updated 12/29/2019] (Bp-Rp)(B8V) = -0.155 ; Evans18 trend for V-I=-0.108 (G-V)(B8V) = -0.06224 ; HIP_26621 B8V E(B-V)=0.001 (G-V)(B8V) = 0.00106 ; HIP_3025 B8VpSi E(B-V)=0.006 (G-V)(B8V) = 0.0069 ; HIP_8629 B8V E(B-V)=0.000 (G-V)(B8V) = 0.00757 ; HIP_23921 B8Vne E(B-V)=0.006 (G-V)(B8V) = 0.01222 ; HIP_28322 B8V E(B-V)=0.003 (G-V)(B8V) = 0.01351 ; HIP_328 B8V E(B-V)=0.007 (G-V)(B8V) = 0.01404 ; HIP_3820 B8V E(B-V)=0.007 (G-V)(B8V) = 0.01548 ; HIP_37514 B8V E(B-V)=0.008 (G-V)(B8V) = 0.016 ; fit for B dwarfs from Kervella19 corrected for E(B-V), eval for (V-Ks)=-0.254 (G-V)(B8V) = 0.01922 ; HIP_37746 B8V E(B-V)=0.007 (G-V)(B8V) = 0.02132 ; HIP_32657 B8V E(B-V)=0.006 (G-V)(B8V) = 0.02133 ; HIP_8352 B8V E(B-V)=0.009 (G-V)(B8V) = 0.02234 ; HIP_36608 B8V E(B-V)=0.009 (G-V)(B8V) = 0.02436 ; HIP_117932 B8V E(B-V)=0.005 (G-V)(B8V) = 0.03522 ; HIP_34537 B8V E(B-V)=0.000 (G-V)(B8V) = 0.04531 ; HIP_67702 B8V E(B-V)=0.009 (G-V)(B8V) = 0.06285 ; HIP_63695 B8V E(B-V)=0.008 (G-V)(B8V) = 0.08007 ; HIP_11318 B8V E(B-V)=0.002 => adopt (G-V)(B8V) = 0.016 [updated 4/8/2022] V-I(B8V) = -0.085 ; Bessell79 R-I(B8V) = -0.050 ; Bessell79 (g-r)(B8V) = -0.33 ; Covey07 Teff(B8V) = 11040 K ; Bertelli09[ATLAS] Teff(B8V) = 11481 K ; sec. stan. 21 Tau median Teff (see below) Teff(B8V) = 11500 K ; GrayCorbally09 Teff(B8V) = 11550 K ; GrayCorbally94 Teff(B8V) = 11614 K ; Bessell98 Teff(B8V) = 11678 K ; Flower96 Teff for B-V = -0.10 Teff(B8V) = 11749 K ; Zorec12 median Teff(B8V) = 11900 K ; Schmidt-Kaler82 Teff(B8V) = 12000 K ; Crowther97/Fig.3 Teff(B8V) = 12000 K ; Bohm-Vitense81 Teff(B8V) = 12000 K ; Bessell79 Teff(B8V) = 12092 K ; B-V=-0.106 => Teff(Napiwotski93) Teff(B8V) = 12120 K ; Theodossiou90 Teff(B8V) = 12196 K ; U-B=-0.364 => Teff(Bessell98) Teff(B8V) = 12200 K ; Chavez95 (+200-100K) Teff(B8V) = 12230 K ; ter. stan. bet Lib (median Teff) Teff(B8V) = 12305 K ; sec. stan. HD 224112 median Teff (see below) Teff(B8V) = 12565 K ; B-V=-0.106 => Teff(Bessell98,logg=4.2) Teff(B8V) = 12811 K ; prim. stan. 18 Tau (median Teff) Teff(B8V) = 12923 K ; EEM median of 268 published Teffs for B8V *s => adopt Teff(B8V) = 12300 K (logT = 4.090) [updated 9/16/2019] Mv(B8V) = 0.46 mag ; Cox00 ZAMS interp B-V vs Mv (for B-V=-0.109) Mv(B8V) = 0.22 mag ; median Mv for B2V calc using Kervella19 HIP & Gaia DR2 Mv(B8V) = 0.0 mag ; GrayCorbally09 Mv(B8V) = 0.00 mag ; sec. stan. 21 Tau (see below) Mv(B8V) = -0.10 mag ; pri. stan. 18 Tau (see below) Mv(B8V) = -0.2 mag ; Schmidt-Kaler82 Mv(B8V) = -0.32 mag ; sec. stan. HD 224112 (see below) Mv(B8V) = -0.49 mag ; Wegner07 Mv(B8V) = -1.16 mag ; ter. stan. bet Lib (see below) => adopt Mv(B8V) = 0.00 mag [updated 2/10/2020] => adopt M_Ks(B8V) = 0.254 mag = Mv - (V-Ks) = 0.0 - -0.254 [updated 12/30/2020] BCv(B8V) = -0.829 mag ; Flower96(Teff=12300K, set BCv(5772K)=-0.085) BCv(B8V) = -0.758 mag ; Code76(Teff=12300K, set BCv(5772K)=-0.085) BCv(B8V) = -0.728 mag ; Bessell98(ATLAS9,logg=4.0,Teff=12300K, set BCv(5772K)=-0.085 BCv(B8V) = -0.703 mag ; Balona94(Teff=12300K, set BCv(5772K)=-0.085) BCv(B8V) = -0.694 mag ; Bertone04(ATLAS,Teff=12300K, set BCv(5772K)=-0.085 BCv(B8V) = -0.67 mag ; Schmidt-Kaler82(BCv=-0.80 + 0.13 offset) => adopt BCv(B8V) = -0.73 [updated 9/16/2019; set so that BCv(5772K)=-0.085] logL(B8V) = 2.148 dex ; logL/Teff trend for OB dwarf EBs (Torres10; Teff=12300K) logL(B8V) = 2.188 dex ; Mv = 0.0, BCv=-0.73 => Mbol = -0.730 logL(B8V) = 2.29 dex ; Zorec12 median => adopt logL(B8V) = 2.188 dex [updated 12/27/2020] => adopt Mbol(B8V) = -0.730 mag [updated 12/27/2020] Mass(B8V) = 2.545+-0.026 Msun ; Eclipsing binary zet Phe B (Torres10) Mass(B8V) = 2.632+-0.049 Msun ; Eclipsing binary chi2 Hya B (Torres10) Mass(B8V) = 2.91 Msun ; Harmanec88 Mass(B8V) = 3.35 Msun ; EEM Teff vs. Mass fit for binaries (Teff=12500K) Mass(B8V) = 3.37 Msun ; EEM logL vs. Mass fit for binaries (logL=2.228) Mass(B8V) = 3.39 Msun ; Zorec12 median Mass(B8V) = 3.45 Msun ; Ekers18 ML calibration for logL=2.228 Mass(B8V) = 3.45 Msun ; EEM Mv vs. Mass fit for binaries (Mv=-0.1) Mass(B8V) = 3.504+-0.054 Msun ; Eclipsing binary IQ Per (Torres10) Mass(B8V) = 3.605+-0.078 Msun ; Eclipsing binary chi2 Hya A (Torres10) => adopt Mass(B8V) = 3.38 Msun [updated 1/2/2020] Rad(B8V) = 2.734 Rsun ; Teff=12300K, logL=2.188 => adopt Rad(B8V) = 2.734 Rsun [updated 10/27/2020] # No Standard MK78, Keenan85, Garrison94 do not list B8V standards. # Primary Standards HD 23324 = 18 Tau = HR 1144 B8V: JM53,Garrison67(stan),Lesh68(stan),Cowley69(stan),Hiltner69(stan),Cowley72(stan),MK73,Garrison77(stan),Houk *B8Vn: GarrisonGray94(stan) The MK73 dagger B8V standard. M91: V=5.647+-0.005, B-V=-0.071+-0.002, U-B=-0.360+-0.000 => updated Q-method => (B-V)o=-0.111, (U-B)o=-0.389, E(B-V)= 0.040, Av=0.132. EEM: dereddening Hauck97 ubvy photometry using Castelli91, I find: E(b-y) = 0.093, (b-y)o= -0.112. For d=132 pc (Pleiades) => plx = 7.519 mas => Mv = -0.10 mag. Teffs: 12572K(Hauck97 phot.=>BalonaShobbrook84 beta calib), 12791+-89K(Paunzen05), 12811K(Hauck97 phot.=>Napiwotski93 calib.), 12817K(Hauck97 phot.=>Balona94 calib.), 13210+-640K(Zorec09) => Median Teff = 12811K. # Secondary Standards HD 23432 = 21 Tau = HR 1151 = Asterope = Cl Melotte 22 817 B8V: JM53,Mendoza56,Osawa59,Palmer68,Cowley69,Cowley72(stan),Abt78,Cannon(B8) *B8Vn: GarrisonGray94 *All* Skiff09 types from JM53 to present are B8V or variant. Pleiad. Asterope should be considered an "anchor" B8Vn standard. vsini=205 km/s. Mermillio91: V=5.764, B-V=-0.039, U-B=-0.232 => updated Q-method (10/17/2011) => (B-V)o=-0.083, (U-B)o=-0.265, E(B-V)= 0.044, Av=0.146. EEM: dereddening Hauck97 ubvy photometry using Castelli91, I find: e(b-y) = 0.11, (b-y)o = -0.112. For d=132 pc (Pleiades) => plx = 7.519 mas => Mv = 0.00 mag. Teffs: 11370K(Hauck97 phot.=>BalonaShobbrook84 beta calib.), 11405K(U-Bo=-0.265=>Bessell98), 11556K(Hauck97 phot.=>Balona94 calib.), 11699K(Hauck97 phot.=>Napiwotzki93 calib.) => Median Teff = 11481K. # Tertiary Standards HD 224112 = HR 9050 = HIP 117932 (J2355-3153) *B8V: GarrisonGray94(stan),Jaschek78(Hiltner69),Kennedy83 Cannon: A Skiff08 MK type compendium only lists two types: B8V from both Hiltner69 and GarrisonGray94 (low vsini standard). Mermilliod91: V=6.823, B-V=-0.082, U-B=-0.338 => updated Q-method (10/17/2011) => (B-V)o=-0.104, (U-B)o=-0.354, E(B-V)= 0.022, Av=0.070 mag. EEM dereddened Hauck97 ubvy photometry using Castelli91, and I find: E(b-y) = 0.069, (b-y)o = -0.109. vanLeeuwen07 plx = 3.85+-0.44 mas => D = 260+-30 pc => Mv = -0.32 mag. Teffs: 12105K(U-Bo=>Bessell98), 12257K(Hauck97 phot. =>BalonaShobbrook84 beta calib.), 12352K(Hauck97 phot. =>Napiwotzki93 calib.), 12356K(Hauck97 phot. =>Balona94 calib.), Median Teff = 12305K. HD 135742 = bet Lib = Zubeneshamali *B8V: MK43,Jaschek78(JM53),Garrison67(stan),Jaschek64(all),Molnar72 B8Vn: Buscombe65 B8IIIn: Houk99(Garrison) B8: Cannon Good luck pronouncing this star. Everyone agrees on B8 type. vsini=230 km/s. J1517-0922. Mermilliod91: V=2.614, B-V=-0.109, U-B=-0.365 => updated Q-method (10/17/2011) => E(B-V) = -0.004, i.e. unreddened, consistent with its nearby distance (VanLeeuwen07 plx = 17.62+-0.16 mas => D = 56.75+-0.52 pc). Mv = -1.16+-0.02 mag. The absolute magnitude suggests that it might be somewhat evolved compared to the other B8V standards. Hauck97 photometry dereddened using Castelli91: (b-y)0=-0.113, c0=0.736, E(b-y)=0.078, Av=0.340. Teffs: 11579K(Hauck97 phot.=>BalonaShobbrook84 beta calib.), 11886K(Hauck97 phot.=>Balona94 calib.), 12205K(U-Bo=>Bessell98), 12254K(Hauck97 phot.=>Napiwotzki93 calib.), 12300+-550K(Zorec09), 12946+-449K(Wu11) => median Teff = 12230K. logg=4.12+-0.16(Wu11), [Fe/H]=0.33+-0.17(Wu11). HD 142315 B7V:: Slettebak68 *B8V: Garrison67,Jaschek78(Garrison79(stan)),WiegertGarrison98(stan),Cannon(B8) B8Vnn: GarrisonGray94 B9V: Bertiau58,Jaschek64(all),Houk88 Upper Sco member. At least Garrison used as standard. # Variant (two "B8Ve" standards) HD 183914 = HR 7418 = bet Cyg B = bet02 Cyg = 6 Cyg B = HIP 95951 B8V: Jaschek78(JM53),Jaschek64(most),Cowley69(B8Vn),Cowley72(stan),Abt88 B8Ve: Slettebak63,Slettebak82,Steele99,Levenhagen06 B8IV/V(e): Slettebak66 B9: Cannon B7V: Osawa59 B9.5V: Herman59 BetCyg A is K4II (V=3.0; Albereo). Mermilliod91: V=5.121, B-V=-0.095, U-B=-0.312 => E(B-V) = -0.001, hence apparently unreddened. VanLeeuwen07 plx = 7.51+-0.33 mas => D = 133+-6 pc. Probably a good "B8Ve" standard. HD 58715 = bet CMi = MWC 178 B8V: MK43,Garrison96,Jaschek64(all),Jaschek78(Slettebak54) B8Ve: Levenhagen06,Slettebak82 B8IV/Ve shell : Slettebak66 B8: Cannon In Jaschek catalog of Be stars. Everyone agrees on B8 subtype. Good "B8Ve" standard? Mermilliod91: V=2.894, B-V=-0.097, U-B=-0.289 => updated Q-method => E(B-V) = -0.009, so probably unreddened. VanLeeuwen07 plx = 20.17+-0.20 mas => D = 49.6 +- 0.5 pc. # Deprecated Standard HD 19356 = Beta Per = Algol (3 components) B8V: MK43,Jaschek64(all),Jaschek78(Slettebak54),GrayAtlas,Gray03 B8Vs: GarrisonGray94 B8: Cannon B8/9V: Hill75 HD 19356 was the HD standard for B8 (1918AnHar..91.....C) and the B8V standard for MK43. Prototypical eclipsing binary with 2.8 day period and K-type companion. Not clear if this is the best choice of standard. The primary has multiple B8V listings - I only consider it a deprecated standard due its eclipsing binary nature, and it was never again considered a standard by e.g. JM53, MK73, MK78, etc. M91: V=2.121+-0.003, B-V=-0.050+-0.001, U-B=-0.370+-0.050 => updated Q-method (10/17/2011) => (B-V)o=-0.118, (U-B)o=-0.419, E(B-V)=0.068, Av=0.222. HD 87901 = Alf Leo = Regulus = 32 Leo = HR 3982 = GJ 9316A B7V: JM53,Osawa59,Jaschek64(major. are B7V),Cowley72(stan),Jaschek78(Murphy69),Garcia89,Garrison96(B7Vn) B8IVn: Gray03 B8III: Williams36 B8V: MK43,GarrisonGray94(B8Vnn),Palmer68(B8Vn),Cannon(B8) Oscillates between B7V and B8V in the literature (both Garrison & Gray have called it both B7V and B8V. Cannon then MK43 called it B8V, then JM53 called it B7V and it was B7V in most literature until Garrison and Gray considered it a B8V again. Probably not a great choice of standard given the changes in published type for this star. Definitely cooler than the other B7V standards, so B8V might be more appropriate anyway. vanLeeuwen07 plx = 41.13+-0.35 mas, Mv = -0.57 mag (so probably negligibly reddened!). The only B7V star in the Hipparcos catalog within 100 pc. B-V = -0.087+-0.015 mag => somewhat redder than the other B7V standards. Mermilliod91: V=1.357+-0.013, B-V=-0.112+-0.005, U-B=-0.365+-0.011 (revised Q-method suggests E(B-V)=0.00). Hauck97 photometry dereddened following Castelli91 => (b-y)0=-0.111, c0=0.698, E(b-y)=0.074, Av=0.326. Teffs: 11535K(Zorec09), 11949K(Hauck97 phot.=>BalonaShobbrook84 beta calib.), 11962K(Gray03), 12254K(Hauck97 phot.=>Balona94 calibration), 12357K(Hauck97 phot.=>Napiwotzki93 calibration), 12360K(Gerbaldi01), 12540K(LeBorgne03), 12862+-200K(Wu11), 14231+-314K(vanBelle09) => median Teff = 12357K. logg=3.56(Gray03), 4.05+-0.09(Wu11). [M/H]=0.00(Gray03), [Fe/H]=0.21+-0.09(Wu11). HD 222173 = iot And B8V: JM53,Cowley72(stan),Jaschek64(all),Cannon(B8) B8IIIs: GarrisonGray94 GarrisonGray94 switched it to giant, but previouly dwarf since JM53. So no longer a good dwarf standard. SB. Jaschek98 lists Mv=-1.5, so much brighter than the other B8 dwarfs. HD 214923 = zet Peg = 42 Peg = HR 8634 B8V: JM53,Osawa59,Palmer68,Cowley72(stan),Cannon(B8) B8.5III: GarrisonGray94 B8.5V: Jaschek64(both) GarrisonGray94 switched it to giant, but previous dwarf since JM53. So no longer a good dwarf standard. Jaschek98 lists Mv=-0.6. HD 36865 = Parenago 1491 (J0534-0429) B8V: Abt68,Bernacca68,Schild71,Houk99 B7V: AbtLevato77 B9: Cannon,Bernacca68 B8/9: Sharpless52 Houk99 comments "UNDETECTED VISUAL DOUBLE p=142°, d=0.8arcsec MAGS 7.6, 9.4; vSINi=220" Abt68 calls "B8V" standard, but then "B7V" in Abt77. Binary. Probably not a good standard. # Non-standard Stars HD 35834 B8Vn: Sharpless52(B8V), Abt77, Abt08