B6V

Garrison94 does not list a B6V anchor standard, and MK73 does not list
a B6V dagger standard. MK73 does list 19 Tau as a B6IV dagger
standard, however.

JM53 standards:        19 Tau - B6V
                       bet Sex (=30 Sex) - B6V
Garrison67 standard:   19 Tau - B6V
Lesh68 standard:       bet Sex - B6V
Cowley69 standard:     19 Tau - B6V
Houk75 standard:       HR 2360 - B6V (sec. standard - adopted from Hiltner69)
WiegertGarrison98 st.: bet Sex - B6V

Dereddening calculations using Q-method in this file have been updated
using the new calibration (10/10/2011).

B-V(B6V) = -0.124  ; prim. stan. HD 45796 (EEM dereddened)
B-V(B6V) = -0.139  ; prim. stan. bet Sex (EEM dereddened via Q-method))
B-V(B6V) =  -0.14   ; Morgan53, Johnson63, Johnson66, Garrison67
B-V(B6V) =  -0.14   ; Fitzgerald70
B-V(B6V) = -0.142  ; dereddened B-V for 34 HIP B6V stars (Q-method,E(B-V)<0.1)
B-V(B6V) =  -0.15   ; SchmidtKaler82
B-V(B6V) = -0.15   ; weak stan. 19 Tau (Pleiad)
=> adopt (B-V)(B6V)  = -0.140  [updated 9/26/2019]

U-B(B6V) = -0.447  ; sec. stan. HD 45796 (EEM dereddened via Q-method)
U-B(B6V) =  -0.49  ; Johnson63, Johnson66, Fitzgerald70
U-B(B6V) =  -0.50  ; Bessell98, Schmidt-Kaler82
U-B(B6V) = -0.504  ; pri. stan. bet Sex (EEM dereddened via Q-method)
U-B(B6V) = -0.521  ; EEM dereddened N=34 HIP B6V stars (Q-method,E(B-V)<0.1)
=> adopt (U-B)(B6V)  = -0.504 ***  [updated 9/26/2019]
=> adopt     Q(B6V)  = -0.403 (=(U-B)-0.72*(B-V) = -0.504 - 0.72*-0.140)
=> adopt (V-I)(B6V)  = -0.144
=> adopt (V-R)(B6V)  = -0.062
=> adopt (R-I)(B6V)  = -0.082

(V-Ks)(B6V) = -0.215 ; HIP_52678_ B6Vnn d= 149.522pc, (B-V)=0.018 (dereddened from Kervella19)
(V-Ks)(B6V) = -0.320 ; HIP_46283_ B6V d= 127.421pc, (B-V)=0.006 (dereddened from Kervella19)
(V-Ks)(B6V) = -0.325 ; HIP_18216_ B6V d= 100.231pc, (B-V)=0.001 (dereddened from Kervella19)
(V-Ks)(B6V) =-0.358  ; from intrinsic color sequence for (U-B)o=-0.504
(V-Ks)(B6V) = -0.359 ; HIP_27534_ B6V d= 181.554pc, (B-V)=0.008 (dereddened from Kervella19)
(V-Ks)(B6V) = -0.369 ; HIP_112781_ B6V d= 157.183pc, (B-V)=0.008 (dereddened from Kervella19)
(V-Ks)(B6V) = -0.387 ; HIP_105282_ B6V d= 168.89pc, (B-V)=0.015 (dereddened from Kervella19)
(V-Ks)(B6V) = -0.404 ; HIP_30524_ B6V d= 218.771pc, (B-V)=0.008 (dereddened from Kervella19)
=> adopt (V-Ks)(B6V) = -0.358 [updated 4/8/2022]
=> adopt (V-J)(B6V)  = -0.270 [updated 4/8/2022]
=> adopt (V-H)(B6V)  = -0.351 [updated 4/8/2022]
=> adopt (H-Ks)(B6V) = -0.007 [updated 4/8/2022]
=> adopt (J-H)(B6V)  = -0.081 [updated 4/8/2022]

(Ks-W1)(B6V) = 0.030 ; EEM trend for d<30pc for B-V=-0.128
=> adopt (Ks-W1)(B6V) = 0.030 [updated 12/29/2019]

(Bp-Rp)(B6V) = -0.203 ; Evans18 trend for V-I=-0.144

(G-V)(B6V) =  0.01094 ; HIP_20554 B6V E(B-V)=0.006
(G-V)(B6V) =  0.010   ; fit for B dwarfs from Kervella19 corrected for E(B-V), eval for (V-Ks)=-0.358
=> adopt (G-V)(B6V) = 0.010 [updated 4/8/2022]

(g-r)(B6V) = -0.39 ; Covey07 (listed for "B5/7V")

Teff(B6V) =  13090 K ; Bertone04[ATLAS]
Teff(B6V) =  13197 K ; Flower96 Teff for B-V = -0.14
Teff(B6V) = 13677 K ; Zorec12 median
Teff(B6V) =  13777 K ; B-V=-0.14 => Teff(Napiwotzki93)
Teff(B6V) = 13804 K ; Simon-Diaz17 for B6V (N=3)
Teff(B6V) = 13827 K ; U-B=-0.504 => Teff(Bessell98)
Teff(B6V) = 13849 K  ; sec. stan. HD 45796 (median Teff)
Teff(B6V) =  13932 K ; Bessell98
Teff(B6V) =  14000 K ; Crowther97/Fig.3 
Teff(B6V) =  14000 K ; interp. (B5V-B7V) GrayCorbally09
Teff(B6V) =  14000 K ; Schmidt-Kaler82 
Teff(B6V) =  14100 K ; Bohm-Vitense81
Teff(B6V) =  14340 K ; Theodossiou90
Teff(B6V) = 14533 K  ; pri. stan. bet Sex (median Teff)
Teff(B6V) =  14550 K ; Chavez95 (+150-100K)
Teff(B6V) = 14791 K ; B-V=-0.14 => Teff(Bessell98,logg=4.3)
Teff(B6V) = 14850 K ; EEM from 95 published Teffs for B6V stars
=> adopt Teff(B6V) = 14500 K (logT = 4.161) [updated 10/18/2019]

Mv(B6V) = -0.02 mag ; Upper Sco MS Mv for B-V=-0.140
Mv(B6V) = -0.04 mag ; Cox00 ZAMS for B-V=-0.14
Mv(B6V) = -0.1  mag ; HD 90994 (Jaschek98)
Mv(B6V) = -0.31 mag ; ONC MS Mv for B-V=-0.140
Mv(B6V) = -0.40 mag ; pri. stan. bet Sex (see below)
Mv(B6V) = -0.49 mag ; pri. stan. HD 45796 (see below)
Mv(B6V) = -0.55 mag ; EEM interp trend logT vs. Rad for B6V
Mv(B6V) = -0.57 mag ; median Mv for B6V calc using Kervella19 HIP & Gaia DR2
Mv(B6V) =  -0.89 mag ; Wegner07
Mv(B6V) = -0.9  mag ; HD 23338 (Jaschek98)
Mv(B6V) =  -0.9  mag ; GrayCorbally09
Mv(B6V) =  -0.9  mag ; Schmidt-Kaler82 
=> adopt Mv(B6V)   = -0.55  mag [updated 12/26/2020]
=> adopt M_Ks(B6V) = -0.192 mag = Mv - (V-Ks) = -0.55 - -0.358 [updated 12/30/2020]

BCv(B6V) = -1.257 mag ; Code76(Teff=14500K, set so BCv(5772K)=-0.085)
BCv(B6V) = -1.244 mag ; Flower96(Teff=14500K, set so BCv(5772K)=-0.085)
BCv(B6V) = -1.134 mag ; Bessell98(ATLAS9,logg=4.0,Teff=14500K, set so BCv(5772K)=-0.085)
BCv(B6V) = -1.109 mag ; Balona94(Teff=14500K, set so BCv(5772K)=-0.085)
BCv(B6V) = -1.084 mag ; Bertone04[ATLAS,Teff=14500K, set so BCv(5772K)=-0.085)
BCv(B6V) =  -1.08 mag ; Schmidt-Kaler82(BCv=-1.21+0.13 offset)
=> adopt BCv(B6V) = -1.13 [updated 9/16/2019, set so that BCv(5772K)=-0.085]

logL(B6V) = 2.510 dex ; logL/Teff trend for OB dwarf EBs (Torres10; Teff=14500K)
logL(B6V) = 2.568 dex ; Mv=-0.55, BCv=-1.13 mag => Mbol = -1.680
logL(B6V) = 2.628 dex ; Zorec12 median for B6V
=> adopt logL(B6V) =  2.568 dex [updated 12/27/2020]
=> adopt Mbol(B6V) = -1.680 mag [updated 12/27/2020]

Mass(B6V) =  3.80 Msun ; Harmanec88
Mass(B6V) = 3.921+-0.045 Msun ; Eclipsing binary zet Phe (Torres10)
Mass(B6V) = 4.14 Msun ; EEM Teff vs. Mass fit for binaries (Teff=14500K)
Mass(B6V) = 4.29 Msun ; Zorec12 median for B6V
Mass(B6V) = 4.30 Msun ; EEM Mv vs. Mass fit for binaries (Mv=-0.7)
Mass(B6V) = 4.31 Msun ; EEM logL vs. Mass fit for binaries (logL=2.628)
Mass(B6V) = 4.32 Msun ; Bertelli09 solar tracks Teff=14500,logL=2.628
Mass(B6V) = 4.36 Msun ; Ekers18 ML calibration for logL=2.628
Mass(B6V) = 4.739+-0.072 Msun ; Eclipsing binary U Oph B (Torres10)
=> adopt Mass(B6V) = 4.3 Msun [updated 9/16/2019]

Rad(B6V) = 3.047 Rsun ; logL=2.568, Teff=14500K
=> adopt Rad(B6V) = 3.047 Rsun [updated 12/27/2020]

# No standard

MK43, Hiltner69, Cowley72, MK73, Garrison77, MK78, Garrison79,
Keenan85, GrayAtlas, & GrayNstars do not list B6V standard.
Skiff08 did not flag any B6V stars as standards.

Although Garrison77 does not list a B6V standard, they classify 3
stars as B6V.  The brightest are HD 152909 (V=6.6; B6V) and HD 112999
(V=7.4; B6V).

# Primary Standards

bet Sex = HD 90994 = 30 Sex = HR 4119
 *B6V: JM53(stan),Jaschek64(most),Kennedy83(Lesh68(stan))
  B5: Cannon
  B5IV/V: Houk99

  Most recent classification is Lesh68.  V=5.071, B-V=-0.139,
  U=B=-0.504 (Mermilliod91) => updated Q-method (10/10/2011) => find
  exactly negligible reddening (E(B-V)=-0.002) with and (B-V)o=-0.137,
  (U-B)o=-0.501, E(B-V)=Av=0.00.  vanLeeuwen07 plx = 8.06+-0.36 mas =>
  Mv = -0.40+-0.10 mag. Hauck97 photometry dereddened using
  Castelli91: (b-y)0=-0.110, c0=0.472, E(b-y)=0.048, Av=0.208.  Teffs:
  14065K(U-Bo=>Bessell98), 14343K(Hauck97 phot.=>Napiwotski93 cal.),
  14533K(Hauck97 phot.=>Balona94 cal.), 14561K(Hauck97
  phot.=>BalonaShobbrook84 cal.), 15272K(Philip80) => median Teff =
  14533K.

# Secondary Standard

HD 45796 = HR 2360 
 *B6V: Jaschek78(Hiltner69),Houk(sec.standard),Houk75,Kennedy83(Hiltner69)
  B5: Cannon

  At least Hiltner69 & Houk agree on B6V type. I call it a secondary
  standard as no one else (e.g. Morgan, Johnson, etc.) considered it a
  standard. V=6.262, B-V=-0.141, U-B=-0.460 (Mermilliod 1991) =>
  revised Q-method (10/10/2011) => find negligible reddening
  (E(B-V)=-0.017) => assume E(B-V) = Av = 0.00, so star "dereddens" to
  sequence at (B-V)o = -0.124, (U-B)o = -0.447.  Teff = 14400 K
  (Philip80). vanLeeuwen07 plx = 4.46+-0.35 mas => Mv = -0.49+-0.17
  mag. Hauck97 photometry dereddened using Castelli91: (b-y)o=-0.109,
  c0=0.526, E(b-y)=0.047, Av=0.205.  Teffs: 13076K(U-Bo=>Bessell98),
  13649K(Hauck97 phot.=>Napiwotski93), 13849K(Hauck97
  phot.=>BalonaShobbrook84 beta calib.), 13889K(Hauck97
  phot.=>Balona94), 14400K(Philip80) => median Teff = 13849K.

# Deprecated Standard

19 Tau = HD 23338 = HR 1145 = HIP 17531 = Taygeta (a Pleiad)
  B6V: JM53(stan),Mendoza56,Cowley69(stan),Jaschek78(Herbig55)
 *B6IV: Kennedy83(all),MK73(dagger),Lesh68
  B5: Cannon

  Skiff09 comments that Cannon18 uses Taygeta as B5 standard for HD
  types!  Skiff09 lists no published types after MK73. (B-V)o=-0.15,
  V=4.30 => Mv=-1.3. From my eye the Pleiades "turnoff" is at V=3.8.
  Taygete is the bluest MS B-star, just fainter than the terminal MS
  (but still "MS"). But best considered "B6IV" due to MK73?

# Other Stars

Gray01/03/06 lists one B6V star: HIP 109268 (=HD 209952, alf Gru), but all of
its other published types are B5V and B7IV. 

HD 142165 = HR 5906 
  *B6V: Bertiau58,Slettebak68
   B6IVn: Garrison67,Hiltner69

   Upper Sco member. All published subtypes are "B6" either "V" or "IVn".