B9V Garrison94 does not list a B9V anchor standard, and MK73 does not list a B9V dagger standard. B9V has unfortunately been a moving target over the years. The two MK43 standards in B9V were not used by JM53 (how's that for continuity amongst "standard stars"...). Given the opportunity, MK73 and MK78 did not define B9V standard stars. GarrisonGray94 defined all new standards, deprecating both the MK43 and JM53 standards. A standard star is a standard star until (surprise) it is not a standard star. HD 141774 has only previously been considered a B9V standard star by Garrison79, however, it maybe worth resuscitating. It is remarkable as every (7) published classification for this star is B9V (plus a B9 HD type from Cannon!). This is stronger agreement than among any other B9V standard or non-standard star. MK43 standard: alf Peg - B9V del Crv - B9V JM53 standard: alf Del - B9V Garrison67 standard: alf Del - B9V Cowley69 standard: alf Del - B9V Cowley72 standards: del Crv - B9V alf Peg - B9V Garrison79 standards: HD 141774 - B9V (see note above) HD 147012 - B9V GarrisonGray94 standards: ome For A - B9Va (low-vsini) HR 2328 - B9Van (high-vsini) WiegertGarrison98 stan HD 141774 - B9V GrayNstars standard: ome For A (=HR 749A) - B9V Dereddenings using the Q-method in this file have been updated using the revised calibration (10/11/2011). B-V(B9V) = -0.044 ; sec. stan. HR 2328 (EEM dereddened via Q-method) B-V(B9V) = -0.061 ; HD_32309 [one of 3 GarrisonGray94 B9V stars within 75 pc] B-V(B9V) = -0.05 ; JohnsonMorgan53 B-V(B9V) = -0.055 ; sec. stan. Ome For A (EEM dereddened via Q-method) B-V(B9V) = -0.06 ; Morgan53, Johnson63, Johnson66 B-V(B9V) = -0.061 ; HD_16978 [one of 3 GarrisonGray94 B9V stars within 75 pc] B-V(B9V) = -0.065 ; Bessell79 B-V(B9V) = -0.067 ; EEM dereddened N=124 HIP B9V stars (Q-method,E(B-V)<0.1) B-V(B9V) = -0.067 ; EEM 8 d<75 pc B9V Hipparcos stars B-V(B9V) = -0.07 ; Garrison67, Fitzgerald70, Morgan71, SchmidtKaler82 B-V(B9V) = -0.071 ; weak stan. alf Del (EEM dereddened via Q-method) B-V(B9V) = -0.074 ; prim. stan. HD 141774 (EEM dereddened via Q-method) B-V(B9V) = -0.083 ; HD_213998 [one of 3 GarrisonGray94 B9V stars within 75 pc] U-B(B9V) = -0.110 ; sec. stan. HD 45380 (EEM dereddened via Q-method) U-B(B9V) = -0.117 ; HD_16978 [one of 3 GarrisonGray94 B9V stars within 75 pc] U-B(B9V) = -0.125 ; HD_32309 [one of 3 GarrisonGray94 B9V stars within 75 pc] U-B(B9V) = -0.154 ; sec. stan. ome For A (EEM dereddened via Q-method) U-B(B9V) = -0.18 ; Fitzgerald70 U-B(B9V) = -0.183 ; HIP d<75pc S/N>8 B9V N=8 (Mermilliod91 photometry) U-B(B9V) = -0.19 ; Johnson63, Bessell98 U-B(B9V) = -0.200 ; EEM dereddened N=124 HIP B9V stars (Q-method,E(B-V)<0.1) U-B(B9V) = -0.20 ; Schmidt-Kaler82 U-B(B9V) = -0.215 ; weak stan. alf Del (EEM dereddened via Q-method) U-B(B9V) = -0.226 ; pri. stan. HD 141774 (EEM dereddened via Q-method) U-B(B9V) = -0.262 ; HD_213998 [one of 3 GarrisonGray94 B9V stars within 75 pc] => adopt (U-B)(B9V) = -0.20 *** => adopt (B-V)(B9V) = -0.070 => adopt Q(B9V) = -0.150 (=(U-B)-0.72*(B-V) = -0.200 - 0.72*-0.070) => adopt (V-I)(B9V) = -0.061 => adopt (V-R)(B9V) = -0.028 => adopt (R-I)(B9V) = -0.033 => adopt (V-J)(B9V) = -0.087 => adopt (V-H)(B9V) = -0.137 => adopt (H-Ks)(B9V) = 0.016 => adopt (J-H)(B9V) = -0.050 (V-Ks)= +0.031 ; HIP_115115_ B9V d= 70.6514pc, (B-V)=0.002 (dereddened from Kervella19) (V-Ks)= -0.010 ; HIP_1647_ B9V d= 99.0295pc, (B-V)=0.003 (dereddened from Kervella19) (V-Ks)= -0.046 ; HIP_25453_ B9V d= 99.5718pc, (B-V)=0.002 (dereddened from Kervella19) (V-Ks)= -0.054 ; HIP_8016_ B9V d= 89.6941pc, (B-V)=0.004 (dereddened from Kervella19) (V-Ks)= -0.062 ; HIP_76234_ B9V d= 98.9315pc, (B-V)=0.008 (dereddened from Kervella19) (V-Ks)= -0.084 ; HIP_20430_ B9Vnn d= 88.9205pc, (B-V)=0.005 (dereddened from Kervella19) (V-Ks)= -0.095 ; HIP_23362_ B9V d= 60.27pc, (B-V)=0.001 (dereddened from Kervella19) (V-Ks)= -0.103 ; sec. stan. HD 16046 = Ome For A (see below) (V-Ks)= -0.112 ; sec. stan. HD 45380 = HR 2328 (see below) (V-Ks)= -0.113 ; HIP_116971_ B9V d= 47.7692pc, (B-V)=0.000 (dereddened from Kervella19) (V-Ks)= -0.121 ; intrinsic color sequence for (U-B)o = -0.20 (V-Ks)= -0.122 ; HIP_61318_ B9V d= 85.2442pc, (B-V)=0.003 (dereddened from Kervella19) (V-Ks)= -0.123 ; HIP_79101_ B9VspHgMn d= 73.5078pc, (B-V)=0.009 (dereddened from Kervella19) (V-Ks)= -0.127 ; HIP_60183_ B9V d= 97.144pc, (B-V)=0.015 (dereddened from Kervella19) (V-Ks)= -0.142 ; HIP_20171_ B9Vsp d= 83.5282pc, (B-V)=0.003 (dereddened from Kervella19) (V-Ks)= -0.155 ; HIP_75178_ B9Vn d= 82.5083pc, (B-V)=0.013 (dereddened from Kervella19) (V-Ks)= -0.171 ; HIP_24505_ B9V d= 83.7521pc, (B-V)=0.001 (dereddened from Kervella19) (V-Ks)= -0.187 ; HIP_109056_ B9Vn d= 96.8054pc, (B-V)=0.025 (dereddened from Kervella19) (V-Ks)= -0.188 ; HIP_813_ B9Vn d= 90.0739pc, (B-V)=0.005 (dereddened from Kervella19) (V-Ks)= -0.201 ; HIP_77562_ B9V(n) d= 96.2649pc, (B-V)=0.008 (dereddened from Kervella19) (V-Ks)= -0.204 ; HIP_27566_ B9V d= 90.7029pc, (B-V)=0.003 (dereddened from Kervella19) (V-Ks)= -0.311 ; HIP_16611_ B9V d= 97.8378pc, (B-V)=0.001 (dereddened from Kervella19) => adopt (V-Ks)(B9V) = -0.121 [updated 4/8/2022] (Ks-W1)(B9V) = 0.038 ; EEM trend for d<30pc for B-V=-0.07 => adopt (Ks-W1)(B9V) = 0.038 [updated 12/29/2019] (Bp-Rp)(B9V) = -0.092 ; Evans18 trend for V-I=-0.061 (G-V)(B9V) = -0.01205 ; HIP_25443 B9V E(B-V)=0.009 (G-V)(B9V) = -0.00450 ; HIP_35451 B9V E(B-V)=0.000 (G-V)(B9V) = 0.00349 ; HIP_32716 B9V E(B-V)=0.006 (G-V)(B9V) = 0.00396 ; HIP_7676 B9V E(B-V)=0.008 (G-V)(B9V) = 0.00506 ; HIP_108542 B9V E(B-V)=0.008 (G-V)(B9V) = 0.00526 ; HIP_14736 B9V E(B-V)=0.009 (G-V)(B9V) = 0.00647 ; HIP_24212 B9V E(B-V)=0.008 (G-V)(B9V) = 0.00784 ; HIP_32910 B9V E(B-V)=0.005 (G-V)(B9V) = 0.00797 ; HIP_26185 B9V E(B-V)=0.004 (G-V)(B9V) = 0.00864 ; HIP_32196 B9V E(B-V)=0.006 (G-V)(B9V) = 0.00974 ; HIP_2665 B9V E(B-V)=0.003 (G-V)(B9V) = 0.00981 ; HIP_34113 B9V E(B-V)=0.008 (G-V)(B9V) = 0.00988 ; HIP_30088 B9V E(B-V)=0.003 (G-V)(B9V) = 0.01019 ; HIP_115098 B9V E(B-V)=0.009 (G-V)(B9V) = 0.01255 ; HIP_107690 B9V E(B-V)=0.008 (G-V)(B9V) = 0.01299 ; HIP_8751 B9V E(B-V)=0.008 (G-V)(B9V) = 0.01333 ; HIP_20747 B9V E(B-V)=0.007 (G-V)(B9V) = 0.01391 ; HIP_32059 B9V E(B-V)=0.006 (G-V)(B9V) = 0.01407 ; HIP_31890 B9Vn E(B-V)=0.006 (G-V)(B9V) = 0.01412 ; HIP_23326 B9V E(B-V)=0.009 (G-V)(B9V) = 0.01477 ; HIP_37557 B9V E(B-V)=0.009 (G-V)(B9V) = 0.01519 ; HIP_32668 B9V E(B-V)=0.005 (G-V)(B9V) = 0.01558 ; HIP_31993 B9V E(B-V)=0.005 (G-V)(B9V) = 0.01626 ; HIP_20229 B9V E(B-V)=0.008 (G-V)(B9V) = 0.01627 ; HIP_22501 B9V E(B-V)=0.006 (G-V)(B9V) = 0.01672 ; HIP_37838 B9V E(B-V)=0.007 (G-V)(B9V) = 0.01696 ; HIP_37697 B9V E(B-V)=0.009 (G-V)(B9V) = 0.01755 ; HIP_21640 B9V E(B-V)=0.006 (G-V)(B9V) = 0.01763 ; HIP_7222 B9V E(B-V)=0.004 (G-V)(B9V) = 0.01791 ; HIP_29907 B9V E(B-V)=0.009 (G-V)(B9V) = 0.018 ; fit for B dwarfs from Kervella19 corrected for E(B-V), eval for (V-Ks)=-0.121 (G-V)(B9V) = 0.01969 ; HIP_45125 B9V E(B-V)=0.005 (G-V)(B9V) = 0.02023 ; HIP_40273 B9V E(B-V)=0.007 (G-V)(B9V) = 0.02073 ; HIP_118133 B9V E(B-V)=0.007 (G-V)(B9V) = 0.02123 ; HIP_12389 B9V E(B-V)=0.007 (G-V)(B9V) = 0.02201 ; HIP_23146 B9V E(B-V)=0.003 (G-V)(B9V) = 0.02219 ; HIP_21484 B9V E(B-V)=0.006 (G-V)(B9V) = 0.02261 ; HIP_31934 B9V E(B-V)=0.006 (G-V)(B9V) = 0.02359 ; HIP_25213 B9V E(B-V)=0.007 (G-V)(B9V) = 0.02382 ; HIP_79044 B9V E(B-V)=0.007 (G-V)(B9V) = 0.02405 ; HIP_25465 B9V E(B-V)=0.002 (G-V)(B9V) = 0.02416 ; HIP_28944 B9V E(B-V)=0.008 (G-V)(B9V) = 0.02525 ; HIP_81634 B9V E(B-V)=0.007 (G-V)(B9V) = 0.02633 ; HIP_24222 B9V(pSiCr) E(B-V)=0.008 (G-V)(B9V) = 0.02660 ; HIP_42348 B9V E(B-V)=0.005 (G-V)(B9V) = 0.02756 ; HIP_512 B9V E(B-V)=0.005 (G-V)(B9V) = 0.02870 ; HIP_24112 B9V E(B-V)=0.008 (G-V)(B9V) = 0.02900 ; HIP_8445 B9V E(B-V)=0.007 (G-V)(B9V) = 0.03876 ; HIP_4396 B9V E(B-V)=0.007 => adopt (G-V)(B9V) = 0.018 [updated 4/8/2022] V-I(B9V) = -0.055 ; Bessell79 R-I(B9V) = -0.032 ; Bessell79 (g-r)(B9V) = -0.28 ; Covey07 Teff(B9V) = 10330 K ; Bertone04[ATLAS] Teff(B9V) = 10358 K ; sec. stan. HD 16046 EEM median Teff (see below) Teff(B9V) = 10404 K ; sec. stan. HD 45380 EEM median Teff (see below) Teff(B9V) = 10500 K ; Schmidt-Kaler82 Teff(B9V) = 10666 K ; Bessell98 Teff(B9V) = 10700 K ; GrayCorbally09 Teff(B9V) = 10706 K ; B-V=-0.07 => Teff(Napiwotski93) Teff(B9V) = 10715 K ; prim. stan. HD 141774 EEM median Teff (see below) Teff(B9V) = 10715 K ; Zorec12 median Teff(B9V) = 10720 K ; GrayCorbally94 Teff(B9V) = 10746 K ; B-V=-0.07 => Teff(Bessell98) Teff(B9V) = 10962 K ; U-B=-0.20 => Teff(Bessell98) Teff(B9V) = 11000 K ; Crowther97/Fig.3 Teff(B9V) = 11000 K ; Bessell79 Teff(B9V) = 11000 K ; Bohm-Vitense81 Teff(B9V) = 11020 K ; Theodossiou90 Teff(B9V) = 11050 K ; Chavez95 (+150-200K) Teff(B9V) = 11103 K ; median Teff from PASTEL catalog (N=4) for 28 B9V stars from GarrisonGray94 Teff(B9V) = 11490 K ; EEM N=301 Teffs => adopt Teff(B9V) = 10700 K (logT = 4.029) [last updated 10/18/2019] [EEM: There is a sizeable difference between the median Teffs for the B9V standards and the median Teff among 301 Teff estimates for B9Vs in the literature. Given the historical migration of the B9V standards, one could easily argue that there is at least ~+-500K systematic uncertainty in where one should define a median Teff.] BCv(B9V) = -0.38 mag ; Schmidt-Kaler82 (BCv=-0.51 + 0.13 offset) BCv(B9V) = -0.381 mag ; Bertone04[ATLAS,Teff=10700K, set BCv(5772K)=-0.085) BCv(B9V) = -0.396 mag ; Balona94(Teff=10700K, set BCv(5772K)=-0.085) BCv(B9V) = -0.418 mag ; Bessell98(ATLAS,logg=4.0,Teff=10700K, set BCv(5772K)=-0.085) BCv(B9V) = -0.432 mag ; Code76(Teff=10700K, set BCv(5772K)=-0.085) BCv(B9V) = -0.481 mag ; Flower96(Teff=10700K, set BCv(5772K)=-0.085) => adopt BCv(B9V) = -0.42 [updated 9/16/2019, adjusted so that BCv(5772K)=-0.085] Mv(B9V) = 1.96 mag ; sec. stan. HD 45380 (see below) Mv(B9V) = 0.90 mag ; Cox00 ZAMS interp B-V vs Mv (for B-V=-0.07) Mv(B9V) = 0.80 mag ; pri. stan. HD 141774 (see below) Mv(B9V) = 0.7 mag ; GrayCorbally09 Mv(B9V) = 0.72 mag ; median Mv for B9V calc using Kervella19 HIP & Gaia DR2 Mv(B9V) = 0.55 mag ; EEM interp logT vs Rad for B9V Mv(B9V) = 0.48 +- 0.30(sem), +-0.73(st.dev.) ; EEM 8 HIP B9V d<75pc Mv(B9V) = 0.35 mag ; d<60pc Mv(B-V=-0.07) trend Mv(B9V) = 0.2 mag ; Schmidt-Kaler82 Mv(B9V) = 0.10 mag ; Wegner07 Mv(B9V) = -0.90 mag ; sec. stan. ome For A (see below) => adopt Mv(B9V) = 0.50 mag [updated 2/10/2020] => adopt M_G(B9V) = 0.515 mag [updated 12/10/2020] (Mv=0.5, G-V=0.05) => adopt M_Ks(B9V) = 0.621 mag [updated 12/30/2020] (Mv=0.5, V-Ks=-0.121) logL(B9V) = 2.07 dex ; Zorec12 median logL(B9V) = 1.864 dex ; Mv=0.7, BCv=-0.42 => Mbol = 0.080 logL(B9V) = 1.826 dex ; logL/Teff trend for OB dwarf EBs (Torres10; Teff=10700K) => adopt logL(B9V) = 1.864 dex [updated 9/26/2019] => adopt Mbol(B9V) = 0.080 mag [updated 9/26/2019] Mass(B9V) = 2.504+-0.023 Msun ; Eclipsing binary GG Lup B (Torres10) Mass(B9V) = 2.52 Msun ; Harmanec88 Mass(B9V) = 2.68 Msun ; EEM Teff vs. Mass fit for binaries (Teff=10600K) Mass(B9V) = 2.73 Msun ; EEM logL vs. Mass fit for binaries (logL=1.864) Mass(B9V) = 2.80 Msun ; Ekers18 ML calibration for logL=1.864 Mass(B9V) = 2.75 Msun ; Bertelli09 solar tracks Teff=10700K,logL=1.864 Mass(B9V) = 2.769+-0.062 Msun ; Eclipsing binary V451 Oph A (Torres10) Mass(B9V) = 2.81 Msun ; EEM Mv vs. Mass fit for binaries (Mv=0.5) Mass(B9V) = 2.95 Msun ; Zorec12 median Mass(B9V) = 3.253+-0.069 Msun ; Eclpising binary V906 Sco B (Torres10) Mass(B9V) = 3.378+-0.071 Msun ; Eclipsing binary V906 Sco A (Torres10) => adopt Mass(B9V) = 2.75 Msun [updated 9/16/2019] logg(B9V) = 4.0+-0.2 ; HD66684 (SpT=B9V GarrisonGray94; Andrievsky02) logg(B9V) = 4.10 ; HD177756 (SpT=B9V GarrisonGray94; Prugniel07) Rad(B9V) = 2.488 Rsun ; Teff=10700K, logL=1.864 => adopt Rad(B9V) = 2.488 sun [updated 9/26/2019] # No Standard MK73, Houk75, MK78, Keenan85, Garrison94, and GrayAtlas do not list a B9V standard. Skiff08 did not flag any stars as B9V standards. # Primary Standard HD 141774 = HIP 77677 *B9V: Cannon(B9),Bertiau58,Jaschek64(both),Slettebak68,Jaschek78(Garrison67),Garrison79(stan),Houk88 Remarkably, *every* published type for this star is B9 subtype (back to Cannon!), but Garrison79 is the only one to mention it as a standard. It is sometimes mentioned in Upper Sco literature, but its proper motion (pm= -4,-6 mas/yr) is deviant for Sco-Cen/Upper Sco. It is fairly reddened however, with somewhat discrepent reddening estimates, so estimates of its intrinsic colors may not be great for estimating mean for the type. Mermilliod91: V=7.700+-0.000 mag, B-V=0.088+-0.001, U-B=-0.108+-0.009 mag. => updated Q-method calibration => (B-V)o=-0.074, (U-B)o=-0.226, E(B-V)=0.162, Av = 0.532. VanLeeuwen07 plx = 4.17+-0.73 mas. Mv = 0.80. EEM deredden Hauck97 ubvy photometry using Castelli91 dereddening: (b-y)0 = -0.117, c0=0.844, E(b-y)=0.193, Av=0.845. Teffs: 10617K(Hauck97 phot.=>BalonaShobbrook84 beta calib.), 10645K(Hauck97 phot.=>Balona94 calib.), 10715K(deGeus89), 10953K(Hauck97 phot.=>Napiwotzki93 calib.), 11138K(U-Bo=>Bessell98 calib.) => median Teff = 10715K. logg=4.08(deGeus89,photometric). # Secondary Standards HD 16046 = Ome For A = HR 749 = ADS 1954A *B9V: Murphy69,Houk82,Corbally84,GrayGarrison(B9Va;stan) B9: Cannon B9.5V: Jaschek78(Levato75) B9.5IV: Abt85 A0III: Lutz77 Kennedy83 lists A as B9V, B9.5V and A0III. Companion B is A-star at 11" separation (varies from A3V-A8V; V=7.79). Not a particularly strong pedigree. Mostly B9V, but some B9.5/A0. parallax = 6.74+-0.71 mas (van Leeuwen07). V=4.967+-0.007(Hauck97). Mermilliod91: V=4.970, B-V=-0.050, U-B=-0.150. => updated Q-method calibration => (B-V)o = -0.055, (U-B)o=-0.154, E(B-V) = 0.005, Av=0.017. E(B-V)=0.0137+-0.0032(Stassun19/TIC), E(B-V)=0.002(Kervella22,STILISM) => adopt E(B-V)=0.005, Av=0.017 from Q-method. H=5.080+-0.024(2MASS), Ks=5.056+-0.017(2MASS). Predicted photometric distance (using Upper Sco ZAMS) = 60+-12 pc, so the star seems somewhat luminous for a dwarf (Mv=-0.90, delta(Mv,MS) = -1.67!). Hauck97 photometry dereddened following Castelli91: Teffs: 9799K(Hauck97 phot.=>Balona84 beta calib.), 10034K(Hauck97 phot.=>Balona94 calib.), 10257K(Zorec12,TIC/Stassun19), 10458K(Hauck97 phot.=>Napiwotzki93 calib.), 10638K(U-Bo=>Bessell98), 10910+-420K(Zorec09) => median Teff = 10358K. logg=3.4866+-0.0630(Stassun19/TIC). logL=2.372+-0.027dex(Stassun19/TIC). Mass=2.638+-0.338Msun(Stassun19/TIC). (V-Ks)o = (4.967 - 3.1*0.005) - (5.056 - 0.382*0.005) = -0.103. HD 45380 = HR 2328 = HIP 30675 *B9Van: GrayGarrison94(stan) B9V: Houk99 B9.5V: Abt95 A0Vn: Jaschek78(Cowley69),Kennedy83(Cowley69) A0: Cannon WDS: 21" binary, with mag(A)=6.32, mag(B)=9.25. delta(Hp)=2.99+-0.19(HIP). Vsini=200 km/s. Vmag = 6.3. Not a particular strong pedigree, but I give some weight to GrayGarrison94's use as a standard. VanLeeuwen07 Parallax = 13.26+-1.64 mas (d=75+-9 pc). V(A)=6.33(TYC), V(A)=6.346(Hauck97), V(B)=9.19(TYC), V(B)=9.285(Hauck97), B-V(A)=-0.041+-0.004(TYC), B-V(B)=0.511+-0.020(TYC). There does not appear to be resolved U-band photometry. Johnson66 for unresolved: V=6.27, B-V=-0.04, U-B=-0.10. => EEM Q-method => (B-V)o=-0.044, (U-B)o=-0.110, E(B-V)=0.004. i.e. unresolved light is consistent with unreddened. V=6.346(Hauck97), Mermilliod91 lists unresolved joint photometry for A & B: V=6.268+-0.004(Mermilliod91), U-B=-0.029+-0.010(Mermilliod91), U-B=-0.095+-0.287(Mermilliod91). E(B-V)=0.002(Kervella19). Adopt E(B-V)=0.003. 2MASS: J=6.429+-0.024(2MASS), H=6.441+-0.044(2MASS), Ks=6.450+-0.020(2MASS). (V-Ks)o = (6.346 - 3.1*0.003) - 6.450 - 0.382*0.003) = -0.112. Paunzen06 calculates 3 independent Teff estimates: 10406K (ubvy), 10728 (Geneva), and 10914 (UBV). EEM dereddened Hauck97 ubvy photometry following Castelli91, I find Teff(Balona94) = 10115K, Teff(Napiwotski93) = 10402K, Teff(Balona84,beta) = 9998K. Median of 6 Teffs = 10404K. Hipparcos lists V = 6.35 => Mv = 1.96. No published logg values. # Deprecated Standards HD 196867 = alf Del = 9 Del = HR 7906 = HIP 101958 B9V: Chalong52,JM53,Osawa59,Jaschek64(most),Garrison67(stan),Cowley69(stan),Jaschek78(JM53) B9IV-V: Cowley72(stan) *B9IV: MK73,Garcia89,GarrisonGray94(stan) B8: Cannon It appears that this is now a B9IV according to MK73, GarrisonGray94. The good news is that there is strong consensus on the B9 type, so the colors are probably somewhat relevant for help define mean B9 colors. dMv=-1.4 mag -- i.e. more evolved than MS. ZAMS distance is 36+-7 pc, but vanLeeuwen07 plx = 12.85+-0.44 mas => D = 78+-3 pc, and Mv = -0.69. M91: V=3.771+-0.004, B-V=-0.057+-0.005, U-B=-0.204+-0.013 => updated Q-method (10/11/2011) => (B-V)o=-0.071, (U-B)o=-0.215, E(B-V)=0.014, Av=0.047. HD 108767 = del CrV = HR 4757 B9V: MK43,Jaschek64(all),Murphy69 B9Vn: Cowley69 B9.5V: Abt81,Gahm83,Houk88,Mora01 *B9.5IV-n: GrayGarrison87 A0: Cannon Mermilliod91: V=2.948+-0.010, B-V=-0.046+-0.005, U-B=-0.079+-0.017. => updated Q-method => E(B-V) = -0.018 (apparently unreddened given the photometric errors) => hence, (B-V)o = -0.046, (U-B)o = -0.079, E(B-V) = Av = 0.00. VanLeeuwen07 plx = 37.55+-0.16 mas => D = 26.6+-0.1 pc. The photometric distance (assuming the star is on the ZAMS) is ~23+-5 pc. Mv = 0.81 and delta(Mv) = -0.23 - hence close to the main sequence. Delta(V)=5.5 binary. So it looks like this this is now a B9.5, and most say dwarf. Teffs: 10162K(Erspamer03), 10580+-400K(Zorec09). HD 218045 = alf Peg = HR 8781 B9V: MK43,Jaschek64(most),Cowley72(stan) B9III: Osawa59,Jaschek78(Slettebak54),Kennedy83(Palmer68) A0: Cannon A0IV: Abt95 *A0III-IV: GrayGarrison87 MK43 listed alf Peg as one of their two B9V standards, but it was considered III or IV star by most since the 1950s (I adopt GrayGarrison87's type as authoritative. So deprecated as a standard. M91: V=2.483+-0.008, B-V=-0.040+-0.005, U-B=-0.038+-0.029 => updated Q-method (10/11/2011) => I get a mildly negative reddening (E(B-V) = -0.03), perhaps attributable to the large U-B uncertainty or its slightly evolved status. Hence (B-V)o = -0.040, (U-B)o = -0.038, E(B-V) = Av ~ 0.00. Looks like its an evolved either B9 or A0. HD 147012 *B9V: Jaschek78(Garrison67),Garrison79(stan) B9IV: Houk88 A0: Cannon J1620-2536. Mentioned in some Upper Sco/Sco-Cen literature, however pm=+10,-26 (deviant from Upper Sco), and it seems too faint to be a late-B ~5-15 Myr-old star at the distance of Sco-Cen. Not a de Zeeuw/HIP member of Upper Sco. Only Garrison has classified as B9V. HD 36998 = BD-04_1180 (J0535-0435) B9V: Abt68,Houk99 *B9Vn: AbtLevato77 B9: Bernacca67 B8/9: Sharpless52 A0: Parenago54 Abt68 called it a "B9V" standard. Later called "B9Vn" in Abt77. # NOTES The spectral classification survey of GarrisonGray94 contains 28 B9V stars. I queried the PASTEL catalog of stellar atmospheric parameters for these 28 B9V stars. Unfortunately only 4 have Teffs, and only one has a log(g). = 11103 K (+-552 K sem, +-802 K stdev; N=4). Among the GarrisonGray94 B9V stars, the following ones have vanLeeuwen07 revised Hipparcos parallaxes > 13.33 mas (d < 75 pc). Name Name plx(mas) B-V HD_16978 HIP_12394 21.48+-0.09 -0.061 HD_32309 HIP_23362 16.48+-0.25 -0.047 HD_213998 HIP_111497 19.43+-0.25 -0.083