O6.5V The primary standard is HD 93146 (Walborn72,Walborn73,Walborn90) Garrison94 does not list an O6.5V anchor standard, and MK73 does not list a O6.5V dagger standard. (B-V)(O6.5V) = -0.319 ; interp => adopt (B-V)(O6.5V) = -0.319 [updated 2/7/2020] (U-B)(O6.5V) = -1.135 ; interp => adopt (U-B)(O6.5V) = -1.135 [updated 2/7/2020] Teff(O6.5V) = 38905 K ; Simon-Diaz17 median for O6V (N=3) Teff(O6.5V) = 38850 K ; Holgado18 Teff(O6.5V) = 38460 K ; Simon-Diaz14 linear fit for O6.5V Teff(O6.5V) = 38300 K ; EEM trend for O dwarfs 1/2020 ** Teff(O6.5V) = 37870 K ; Martins05(obs. scale),GrayCorbally09 Teff(O6.5V) = 37500 K ; non-stan. NGC 346 MPG 356 (Heap06) & Heap06 adopted for O6.5V Teff(O6.5V) = 37000 K ; Massey05(Milky Way) Teff(O6.5V) = 36826 K ; Martins05(theo. scale) => adopt Teff(O6.5V) = 38300 K (logT = 4.583) [updated 1/20/2020] Mv(O6.5V) = -5.3 mag ; GrayCorbally09 Mv(O6.5V) = -5.05 mag ; Bowen08 Mv(O6.5V) = -5.0 mag ; Russeil03 Mv(O6.5V) = -5.0 mag ; Conti71(V) Mv(O6.5V) = -4.96 mag ; EEM trend for O6.5V Mv(O6.5V) = -4.885 mag ; Wegner07 (halfway between O6V and O7V) Mv(O6.5V) = -4.86 mag ; Garmany92 Mv(O6.5V) = -4.85 mag ; Martins06/theor.scale Mv(O6.5V) = -4.84 mag ; Martins06/obs.scale Mv(O6.5V) = -4.77 mag ; Martins05 Mv(O6.5V) = -4.5 mag ; Conti71(ZAMS) => adopt Mv(O6.5V) = -4.95 mag [updated 2/8/2020] BCv(O6.5V) = -3.767 mag ; Flower96(Teff=38300K),set so BCv(5772K)=-0.085) BCv(O6.5V) = -3.55 mag ; Martins05(obs.scale) BCv(O6.5V) = -3.522 mag ; Bessell98(Teff=38300K),set so BCv(5772K)=-0.085) BCv(O6.5V) = -3.515 mag ; LanzHubeny03/07(Teff=38300K) BCv(O6.5V) = -3.49 mag ; EEM interp O6V(-3.57),O7V(-3.41) BCv(O6.5V) = -3.48 mag ; Martins06(obs.scale) BCv(O6.5V) = -3.47 mag ; Martins05(theor.scale) BCv(O6.5V) = -3.40 mag ; Martins06(theor.scale) BCv(O6.5V) = -3.386 mag ; Balona94(Teff=38300K),set so BCv(5772K)=-0.085) => adopt BCv(O6.5V) = -3.49 [updated 1/31/2020] logL(O6.5V) = 5.272 dex ; Mv=-4.95, BCv=-3.49 => Mbol=-8.440 logL(O6.5V) = 5.239 dex ; EEM trend for O dwarf logL(O6.5V) = 5.23 dex ; Martins05(obs. scale) logL(O6.5V) = 5.20 dex ; Martins05(theo. scale) => adopt logL(O6.5V) = 5.272 dex [updated 2/8/2020] => adopt Mbol(O6.5V) = -8.440 mag [updated 2/8/2020] logg(O6.5V) = 3.82 dex ; Holgado18 => adopt logg(O6.5V) = 3.82 dex [updated 1/31/2020] Rad(O6.5V) = 9.8232 Rsun ; logL=5.272, Teff=38300K Rad(O6.5V) = 9.542 Rsun ; Martins05 (Teff=37871K,logL=5.227) => adopt Rad(O6.5V) = 9.823 Rsun [updated 2/8/2020] Mass(O6.5V) = 30.0+-1.0 Msun ; LS1135A (Weidner10) Mass(O6.5V) = 30+-6 Msun ; Weidner10 Mass(O6.5V) = 31.6 Msun ; MIST/Choi16 solar tracks for logT=4.272,logL=4.272 => adopt Mass(O6.5V) = 31 Msun [updated 4/16/2022] # No Standards MK73, MK78, Garcia89, and Garrison94 do not list an O6.5V standard # Primary Standard HD 93146 (in Collinder 228 cluster) O6.5V: Walborn72 O6.5V((f)): Walborn73,Walborn90(stan) O6V: Levato81 B: Cannon,Houk75 Primary O6.5V((f)) standard in Walborn90, arguably the best standard. # Secondary Standards HD 165052 O6.5V(n)((f)): Walborn73 # Candidate Standard? HD 42088 O6.5V: Conti71,Walborn72 Conti & Walborn agree on O6.5V type # Other Stars Walborn72 classified 9 stars as O6.5V, including HD 93146 and HD 42088. Conti71 classified four stars as O6.5V, with the brightest being HD 42088 (V=7.6).