B5III Although Garrison94 does not list a B5III anchor, it appears that tau Ori could qualify as one. The best southernly accessible standard is tau Ori (J0517-0650; V=3.6) MK43 standard: del Per - B5III JM53 standards: del Per - B5III iot Aql - B5III tau Ori - B5III Garrison67 standard: del Per - B5III Abt68 standard: tau Ori - B5III Lesh68 standards: tau Ori - B5III del Per - B5III Hiltner69 standard: tau Ori - B5III Houk standard: iot Aql - B5III tau Ori - B5III Garrison77 standard: tau Ori - B5III MK78 standard: tau Ori - B5III WiegertGarrison98 st: iot Aql - B5III GrayAtlas standard: tau Ori - B5III GrayNstars standard: tau Ori - B5III Teff(B5III) = 14400 K ; pri. stan. tau Ori (see below) Teff(B5III) = 14400 K ; sec. stan. iot Aql (see below) Teff(B5III) = 14500 K ; sec. stan. del Per (see below) => adopt Teff(B5III) = 14400K BCv(B5III) = -1.226 ; T=14400K Code76 calibration BCv(B5III) = -1.113 ; T=14400K Balona94 calibration BCv(B5III) = -1.139 ; T=14400K Bessell98 calibration BCv(B5III) = -1.089 ; T=14400K Bertoine04 calibration BCv(B5III) = -1.249 ; T=14400K Flower96 calibration => adopt BCv(B5III) = -1.14 mag # Primary Standard tau Ori = HD 34503 (J0517-0650; V=3.6) *B5III: JM53,Lesh68(stan),Abt68(stan),Hiltner69(stan),Houk(stan),Garrison77(stan),MK78,Abt85,GrayNstars B6IV: Zorec09 B5V: Chalonge52 plx=6.60+-0.15mas (HIP2). Teff = 14450+-770K (Zorec09). Zorec09 lists 5 Teff estimates with =14422+-122K(sem) +-301K(rms). E(B-V)=0.045 (Zorec09). # Secondary standards del Per = HD 22928 *B5III: MK43,RomanMorgan50,JM53,Garrison67(stan),Lesh68(stan),Rountree91,Zorec09 B5IVn: Abt78 B6III: Cucchiaro77 B6n: Petri69 In Alpha Per cluster. Teff = 14890+-820K(Zorec09). Zorec09 lists 4 estimates with 14537+-383K(sem) +-546K(stdev). Adopt Teff= 14500K. iot Aql *B5III: JM53,Lesh68,Houk(stan) B5V: 1955MmMtS..12....1W B7III: Cucchiaro80(S/68 UV spectra) Teff=10471K(Allende-Prieto99), 14431+-229K(Wu11), 16000K(Chen14). Adopt Teff = 14400K from Wu11. logg=4.5(Chen14), 3.72+-0.07(Wu11).