B9IV MK73 standard: alf Del (=HR 7906) - B9IV Houk standard: 134 Tau (=HR 2010) - B9IV [from JM53] GrayNstars standard: alf Del (=HR 7906) - B9IV GarrisonGray94 standard: 134 Tau - B9IV [low vsini standard] alf Del - B9IVn [high vsini standard] WiegertGarrison98 stan: alf Del - B9IV GrayNstars standard: alf Del - B9IV B-V(B9IV) = -0.095 ; nearby B9IVp lam Aql = HIP 93805 = HD 177756 (Gray03) B-V(B9IV) = -0.086 ; nearby B9IVn xi Tau = HIP 16083 = HD 21364 (GarrisonGray94) B-V(B9IV) = -0.071 ; nearby B9IVn kap And = HIP 116805 = HD 222439 (GarrisonGray94) B-V(B9IV) = -0.070 ; nearby B9IV HIP 47391 = HD 83944 (GarrisonGray94) B-V(B9IV) = -0.068 ; pri. stan. 134 Tau (see below) B-V(B9IV) = -0.064 ; nearby B9IV bet01 Tuc = HIP 2484 = HD 2884 (GrayGarrison87) B-V(B9IV) = -0.057 ; pri. stan. alf Del (see below) => adopt B-V(B9IV) = -0.07 U-B(B9IV) = -0.160 ; nearby B9IV bet01 Tuc = HIP 2484 = HD 2884 (GrayGarrison87) U-B(B9IV) = -0.164 ; pri. stan. 134 Tau (see below) U-B(B9IV) = -0.204 ; pri. stan. alf Del (see below) U-B(B9IV) = -0.205 ; nearby B9IV HIP 47391 = HD 83944 (GarrisonGray94) U-B(B9IV) = -0.229 ; nearby B9IVn kap And = HIP 116805 = HD 222439 (GarrisonGray94) U-B(B9IV) = -0.265 ; nearby B9IVp lam Aql = HIP 93805 = HD 177756 (Gray03) U-B(B9IV) = -0.334 ; nearby B9IVn xi Tau = HIP 16083 = HD 21364 (GarrisonGray94) => adopt U-B(B9IV) = -0.20 V-Ic(B9IV) = -0.020 ; nearby B9IV bet01 Tuc = HIP 2484 = HD 2884 (GrayGarrison87) V-Ic(B9IV) = -0.050 ; pri. stan. 134 Tau (see below) V-Ic(B9IV) = -0.060 ; nearby B9IV HIP 47391 = HD 83944 (GarrisonGray94) V-Ic(B9IV) = -0.060 ; nearby B9IVn kap And = HIP 116805 = HD 222439 (GarrisonGray94) V-Ic(B9IV) = -0.070 ; nearby B9IVn xi Tau = HIP 16083 = HD 21364 (GarrisonGray94) V-Ic(B9IV) = -0.090 ; nearby B9IVp lam Aql = HIP 93805 = HD 177756 (Gray03) => adopt V-Ic(B9IV) = -0.06 V-Ks(B9IV) = -0.086 ; pri. stan. 134 Tau (see below) Mv(B9IV) = -0.5 ; GrayCorbally09 Teff(B9IV) = 12730K ; nearby B9IVn xi Tau = HIP 16083 = HD 21364 (GarrisonGray94) [med. PASTEL Teff] Teff(B9IV) = 11550K ; nearby B9IV HIP 47391 = HD 83944 (GarrisonGray94) [median PASTEL Teff] Teff(B9IV) = 11435K ; nearby B9IVn kap And = HIP 116805 = HD 222439 (GarrisonGray94) [med. PASTEL Teff] Teff(B9IV) = 11060K ; pri. stan. alf Del (see below) Teff(B9IV) = 10765K ; nearby B9IVp lam Aql = HIP 93805 = HD 177756 (Gray03) [median PASTEL Teff] Teff(B9IV) = 10770K ; nearby B9IV bet01 Tuc = HIP 2484 = HD 2884 (GrayGarrison87) [med. PASTEL Teff] Teff(B9IV) = 10825K ; pri. stan. 134 Tau (see below) => adopt Teff(B9IV) = 11000K logg(B9IV) = 3.94 ; pri. stan. 134 Tau (see below) logg(B9IV) = 3.98 ; pri. stan. alf Del (see below) => adopt logg(B9IV) = 3.96 # Primary Standards HD 38899 = HR 2010 = 134 Tau *B9IV: JM53(non-standard),Houk88,GarrisonGray94(low-vsini stan.),Grenier99,Abt02 B9V: Osawa59,Palmer68,Davis77 B9.5V: Cowley69 B7III: Cucchiaro80 plx = 13.11+-0.33 mag (vanLeeuwen07), hence most likely negligibly reddened. V=4.89(HIP), V=4.897+-0.016(Mermilliod91), B-V=-0.068+-0.004(Mermilliod91), B-V=-0.068+-0.004(HIP), V-Ic=-0.05+-0.01(HIP), U-B=-0.164+-0.022(Mermilliod91). 2MASS J and H are low grade. Ks=4.983+-0.016(2MASS, grade=A). V-Ks = 4.897 - 4.983 = -0.086. logg=4.10(Smith93), 3.97(Schiavon07), 3.90(Adelman84), 3.89+-0.05(Wu11) => adopt log(g) = 3.94. Teffs: 10385+-138K(Wu11), 10715K(AllendePrieto99;logT=4.03), 10752K(Schiavon07), 10825K(Ryabchikova05), 10850K(Smith93), 10957K(Adelman84) => adopt Teff=10825K. HR 7906 = Alf Del *B9IVn: MK73,GarrisonGray94(high-vsini stan.),Zorec09 B9V: JM53,deVaucouleurs57,Osawa59,Palmer68 Johnson & Morgan (1953) originally called it B9V, but Morgan & Keenan (1973) changed it to B9IVn, and all subsequent studies have considered it the B9IVn standard. Star is in Washington Double Star catalog as "WCK 2" with 0.2" separation - quoted magnitudes of 3.86 and 6.43. plx = 12.85+-0.44 mas (vanLeeuwen07), hence it is probably negligibly reddened. V=3.771+-0.004(Mermilliod91), V=3.77(Johnson66), B-V=-0.057+-0.005(Mermilliod91), B-V=-0.06(Johnson66), U-B=-0.204+-0.013(Mermilliod91), U-B=-0.21(Johnson66). 2MASS JHK photometry is flagged grade "DDE", so I won't adopt it. vsini = 138km/s(Zorec12). loggs: 3.96(Prugniel07#1), 3.97(Prugniel07#2), 4.00(Katz11), 4.05+-0.06(Wu11) => adopt logg=3.98. Teffs: 10000K(AllendePrieto99), 10705+-173K(Wu11), 10715+-50K(Zorec12), 11021K(Prugniel07#2), 11110K(Sokolov95), 11110K(Prugniel07#1,Katz11), 11220+-450K(Zorec09), 11721K(Philip80) => adopt Teff = 11060K. Zorec12 estimates: logL=2.3915+-0.0331, Mass=3.46+-0.006, Age = 920+-16 Myr.