A6V

There are no published A6V standards (and of course no anchor or
dagger standards). The best, bright star that I can find that would
probably make a suitable A6V standard is Beta Pic.

# No standard

JM53, Morgan65, Cowley69, MK73, Cowley74, Houk75, MK78, Keenan85,
GrayGarrison89, GrayNstars do not provide a A6V standard

Skiff08 did not flag any stars as A6V MK standards. 

GrayGarrison89 classified 13 stars as A6V or some variant. The
brightest were HD 50241 (= Alf Pic; A6Vn; V=3.2), HD 39060 (= Bet Pic;
A6V; V=3.9), HD 124675A (= Kap^2 Boo; A6V+; V=4.5), HD 79439 (= 18
UMa; A6V; V=4.8), and HD 175639 (= Tet^2 Ser; A6Vn; V=5.0).

Looked for A6Vs in Skiff07 with multiple "A6V" entries:
HD 12140 = HR 578 (3 refs)
HD 29388 = HR 1473 (3 refs)
HD 74591 = HR 3469 (3 refs)
None of these three were in GrayGarrison89

Gray01/03/06 list 2 nearby A6V dwarfs: Median HIP colors:
<V-I>(A6V) = 0.185 (+-0.003 sem, +-0.004 stdev; N=2)

For A6V Hipparcos stars within 75pc, with parallax S/N > 8, 
and within 1 mag of the MS (N=15):
<V-I>(A6V)   = 0.207 (+-0.024 sem, +-0.042 stdev; N=3)
<V-J>(A6V)   = 0.386 (+-0.047 sem, +-0.081 stdev; N=3)
<V-H>(A6V)   = 0.435 (+-0.065 sem, +-0.113 stdev; N=3)
<V-Ks>(A6V)  = 0.503 (+-0.063 sem, +-0.109 stdev; N=3)
<J-H>(A6V)   = 0.049 (+-0.020 sem, +-0.034 stdev; N=3)
<H-K>(A6V)   = 0.068 (+-0.012 sem, +-0.021 stdev; N=3)
<Bt-Vt>(A6V) = 0.205 (+-0.022 sem, +-0.038 stdev; N=3)
<V-Vt>(A6V)  =-0.024 (+-0.002 sem, +-0.004 stdev; N=3)
<B-K>(A6V)   = 0.690 (+-0.083 sem, +-0.145 stdev; N=3)

(B-V)(A6V) = 0.220 ; exemplar HD 195093
(B-V)(A6V) = 0.215 ; exemplar alf Pic
(B-V)(A6V) =  0.209 ; BakisEker22 
(B-V)(A6V) = 0.200 ; exemplar HD 74591 = HR 3469
<B-V>(A6V) = 0.188 ; 15 HIP nearby (+-0.021 sem, +-0.036 stdev; N=3)
(B-V)(A6V) = 0.186 ; exemplar HD 79439
(B-V)(A6V) = 0.186 ; exemplar HD 12140 = HR 578
(B-V)(A6V) = 0.186 ; smoothed trend SpT vs (B-V)o B9.5V-F3V 11/2021
(B-V)(A6V) = 0.185 ; halfway between A5V(0.16) and A7V(0.21)
(B-V)(A6V) = 0.175 ; exemplar HD 2262 = HR 100
(B-V)(A6V) =  0.175 ; Schmidt-Kaler(halfway A5V-A7V)
(B-V)(A6V) = 0.171 ; exemplar bet Pic 
<B-V>(A6V) = 0.170 ; 2 Gray01/03/06 (+-0.001 sem, +-0.001 stdev)
(B-V)(A6V) =  0.17  ; Morgan71 
(B-V)(A6V) =  0.16  ; KenyonHartmann95
(B-V)(A6V) = 0.122 ; exemplar HD 29388
=> adopt (B-V)(A6V)  = 0.185 *** [updated 11/18/2020]
 [EEM note 9/24/2020: B-V=0.180/Teff=8000K smoothly fits on A dwarf sequence]

=> adopt (V-I)(A6V)  = 0.214
=> adopt (V-R)(A6V)  = 0.103
=> adopt (R-I)(A6V)  = 0.111
=> adopt (V-J)(A6V)  = 0.383
=> adopt (V-H)(A6V)  = 0.426
=> adopt (V-Ks)(A6V) = 0.465
=> adopt (H-Ks)(A6V) = 0.039
=> adopt (J-H)(A6V)  = 0.043


(Bp-Rp)(A6V) =  0.0944  ; HD_195093
(Bp-Rp)(A6V) =  0.1722  ; 90_Tau
(Bp-Rp)(A6V) = 0.222   ; color trend for B-V=0.185
(Bp-Rp)(A6V) =  0.2452  ; HD_12140
(Bp-Rp)(A6V) =  0.2563  ; kap_Phe
(Bp-Rp)(A6V) = 0.265   ; Evans18 trend for V-I=0.214
(Bp-Rp)(A6V) =  0.2700  ; 10_Hya
(Bp-Rp)(A6V) =  0.2745  ; bet_Pic
(Bp-Rp)(A6V) =  0.2793  ; 18_UMa
(Bp-Rp)(A6V) =  0.2804  ; HD_195093
=> adopt (Bp-Rp)(A6V)= 0.222 [updated 11/22/2020]

(Bp-G)(A6V) =  0.0454  ; HD_195093
(Bp-G)(A6V) = 0.069   ; color trend for B-V=0.185
(Bp-G)(A6V) =  0.1059  ; HD_12140
(Bp-G)(A6V) =  0.1141  ; 10_Hya
(Bp-G)(A6V) =  0.1170  ; HD_195093
(Bp-G)(A6V) =  0.1241  ; 90_Tau
(Bp-G)(A6V) =  0.1389  ; 18_UMa
(Bp-G)(A6V) =  0.1724  ; kap_Phe
(Bp-G)(A6V) =  0.2274  ; bet_Pic
=> adopt (Bp-G)(A6V) = 0.069 [updated 11/22/2020]

(G-Rp)(A6V) =  0.0471  ; bet_Pic
(G-Rp)(A6V) =  0.0481  ; 90_Tau
(G-Rp)(A6V) =  0.0490  ; HD_195093
(G-Rp)(A6V) =  0.0839  ; kap_Phe
(G-Rp)(A6V) =  0.1394  ; HD_12140
(G-Rp)(A6V) =  0.1404  ; 18_UMa
(G-Rp)(A6V) = 0.152   ; color trend for B-V=0.185
(G-Rp)(A6V) =  0.1560  ; 10_Hya
(G-Rp)(A6V) =  0.1634  ; HD_195093
=> adopt (G-Rp)(A6V) = 0.152 [updated 11/22/2020]

(Ks-W1)(A6V) = 0.046 ; EEM trend for d<30pc for B-V=0.185
=> adopt (Ks-W1)(A6V) = 0.046 [updated 12/29/2019]

(G-V)(A6V) =  -0.040 ; * bet Pic PM* A6V
(G-V)(A6V) = -0.030 ; polynomial trend as f(B-V)
(G-V)(A6V) =  -0.023 ; * 56 Cyg PM* A6V
(G-V)(A6V) =  -0.020 ; HD 154431 PM* A6V
(G-V)(A6V) =  -0.020 ; HD 165189 PM* A6V
(G-V)(A6V) =  -0.019 ; * e UMa dS* A6V
(G-V)(A6V) = -0.013  ; fit for A dwarfs from Kervella19 corrected for E(B-V), eval for (V-Ks)=0.464
(G-V)(A6V) =  -0.006 ; * c Tau PM* A6V
=> adopt (G-V)(A6V) = -0.02 [updated 4/8/2022]

(U-B)(A6V)   = 0.095 ; Fitzgerald70 interp. A5-A7
(U-B)(A6V)   = 0.096 ; U-B vs B-V trend for B-V=0.185
(U-B)(A6V)   = 0.100 ; HIP d<75pc S/N>8 A6V N=3 (Mermilliod91 photometry)
=> adopt (U-B)(A6V)  = 0.096 [updated 11/18/2020]

(g-r)(A6V)   = +0.054 ; Jordi06 (V-R)=>(g-r) for V-R=0.100
(g-r)(A6V)   = -0.049 ; Bilir05 (B-V)=>(g-r) for B-V=0.18
(g-r)(A6V)   = -0.06  ; Covey07 interp. A5V-A7V
=> adopt (g-r)(A6V) = -0.05 [updated 10/10/2020]

Teff(A6V) = 8282 K ; exemplar Hyad HD 29388
Teff(A6V) = 8117 K ; exemplar Hyad HD 28527
Teff(A6V) = 8084 K ; exemplar beta Pic 
Teff(A6V) =  8025 K ; Schmidt-Kaler82(halfway A5V-A7V)
Teff(A6V) = 8002 K ; EEM N=40 Teffs
Teff(A6V) =  7990 K ; interp. (A5V-A7V) GrayCorbally09
Teff(A6V) = 7987 K ; mean photometric Teff
Teff(A6V) = 7980 K ; Zorec12 median
Teff(A6V) = 7975 K ; median Teff for 6 A6V from Gray17
Teff(A6V) =  7935 K ; interp. (A5V-A7V) Theodossiou90
Teff(A6V) = 7894 K ; exemplar HD 2262 = HR 100 = kap Phe 
Teff(A6V) = 7819 K ; exemplar HD 195093
Teff(A6V) = 7816 K ; exemplar HD 79439 = HR 3662 = 18 UMa
Teff(A6V) = 7775 K ; exemplar HD 12140
Teff(A6V) = 7762 K ; exemplar HD 74591 = HR 3469 = 10 Hya
Teff(A6V) = 7510 K ; exemplar alf Pic 
Teff(A6V) =  7480 K ; Boyajian12
=> adopt Teff(A6V) = 7910 K (logT = 3.8982) [update 11/18/2020]
[EEM 9/24/2020: note Teff adjusted down a tad to maintain Teff/Rad/logL sequence]

BCv(A6V)  = -0.052 mag ; Flower96(Teff=8000K, BCv(5772K)=-0.085)
BCv(A6V)  =  -0.005 mag ; Schmidt-Kaler82(halfway A5V-A7V + 0.13 offset)
BCv(A6V)  = -0.004 mag ; Bessell98(ATLAS9,logg=4.5,Teff=7920K)
BCv(A6V)  = +0.000 mag ; Code76(Teff=7910K, BCv(5772K)=-0.085)
BCv(A6V)  = +0.005 mag ; A5V BCv=0.00, A7V BCv=+0.01
BCv(A6V)  = +0.010 mag ; EEM trend mid-As
BCv(A6V)  = +0.036 mag ; Balona94(Teff=7920K, BCv(5772K)=-0.085)
BCv(A6V)  = +0.028 mag ; Masana06(Teff=7920K, BCv(5772K)=-0.085)
BCv(A6V)  = +0.041 mag ; Bertone04(ATLAS,Teff=7920K, BCv(5772K)=-0.085)
=> adopt BCv(A6V) = 0.005 [updated 11/18/2020, set for BCv(5772K)=-0.085]

logg(A6V) = 4.2 ; median logg for 6 A6V from Gray17

Mv(A6V) =  2.48 mag ; exemplar HD 195093 
Mv(A6V) =  2.40 mag ; exemplar bet Pic (ZAMS)
Mv(A6V) =   2.2  mag ; interp. (A5V-A7V) GrayCorbally09
Mv(A6V) = 2.12 mag ; A dwarf B-V vs. Mv seqence for B-V=0.185
Mv(A6V) =  2.08 mag ; exemplar HD 74591 = HR 3469
Mv(A6V) =  2.07 mag ; median Mv for A6V calc using Kervella19 HIP & Gaia DR2 (d<100pc)
Mv(A6V) =  2.06 mag ; exemplar HD 79439 (18 UMa)
Mv(A6V) =   2.05 mag ; Schmidt-Kaler82 (halfway A5V-A7V)
Mv(A6V) =  2.03 mag ; interp BAF dwarf seq for B-V=0.185
Mv(A6V) =  1.94 mag ; linear B-V vs. Mv fit to d<50pc Gray01/03/06 dwarfs for B-V=0.18
Mv(A6V) =  1.93 mag ; Wright05(B-V=0.18)
Mv(A6V) =  1.82 mag ; d<60pc Mv(B-V=0.17)
Mv(A6V) =   1.46 mag ; Wegner07
Mv(A6V) =  0.90 mag ; exemplar HD 29388 (Hyad)
Mv(A6V) =  0.90 mag ; exemplar alf Pic 
=> adopt Mv(A6V)   = 2.12  mag [updated 11/18/2020]
=> adopt M_G(A6V)  = 2.09  mag [updated 12/10/2020] (Mv=2.12, G-V=-0.03)
=> adopt M_Ks(A6V) = 1.655 mag [updated 12/30/2020] (Mv=2.12, V-Ks=0.465)
 
logL(A6V) = 1.046 dex ; Mv=2.12 & BCv=0.005 mag => Mbol = 2.125
logL(A6V) = 1.59  dex ; Zorec12 median
=> adopt logL(A6V) = 1.046 dex [updated 11/18/2020]
=> adopt Mbol(A6V) = 2.125 dex [updated 11/18/2020]

Mass(A6V) = 2.24 Msun ; Zorec12 median
Mass(A6V) = 1.85 Msun ; EEM Mv vs. Mass fit for binaries (Mv=1.89)
Mass(A6V) = 1.84 Msun ; Ekers15 ML calibration for logL=1.14
Mass(A6V) = 1.83 Msun ; EEM Teff vs. Mass fit for binaries (Teff=8000K)
Mass(A6V) = 1.82 Msun ; EEM logL vs. Mass fit for binaries (logL=1.14)
Mass(A6V) = 1.730+-0.025 Msun ; Eclipsing binary IQ Per B (Torres10)
=> adopt Mass(A6V) = 1.83 Msun [update 9/16/2019]

Rad(A6V) = 1.7754 Rsun ; logL=1.046 ,Teff=7910K
Rad(A6V) = 1.544 Rsun ; bet Pic HIP 27321, Stassun19 (note: ZAMS ~20 Myr)
=> adopt Rad(A6V) = 1.7754 Rsun [updated 11/18/2020]

# Exemplars

bet Pic = HD 39060 = HR 2020 
  A3V: Evans61
  A4V: Paunzen01
  A5V: Houk75(Garrison,unpub)
  A5IV: Slettebak82,Slettebak75(A5IVp)
  A5/7: Blondel06(IUE)
 *A6V: GrayGarrison89,Abt95,Gray06

  *Not* an MK standard. The brightest A6V star in GrayGarrison89, and
  a ~23 Myr-old famous ZAMS stars with debris disk and giant planet.
  Gray, Garrison, & Abt have all classified this star as A6V.  B-V =
  0.171+-0.002 (HIP), V-I = 0.18+-0.02 (HIP),
  V=3.845+-0.005(Mermilliod91), plx=51.44+-0.12mas(HIP2) => Mv =
  2.402+-0.007(Mermilliod91,HIP2). Teffs: 7995K(Saffe08/C97),
  8035+-74K(Zorec12), 8039K(Stassun19), 8045+-97K(Blackwell98), 8052K(Gray06),
  8084K(Schroeder09), 8128K(AllendePrieto99), 8157K(Saffe08/N93),
  8200K(Holweger95), 8230+-350K(Sokolov95), 8300+-282K(David15),
  8500K(Mittal15), 8543K(daSilva09) => <Teff> = 8143K(N=12; sem=+-67K;
  true median) Saffe08(N93 fit) lists logg=4.23, [Fe/H]=0.00, and (C97
  fit) logg=3.95, [Fe/H]=0.17.  Holweger95 reports logg=4.24.
  Defrere2012 reports angular diameter: 0.736+-0.015+-0.012 mas
  (0.736+-0.019 mas), taking into account a ~1.48% K-band excess due
  to dust. At HIP2 distance 19.4401 +- 0.0454 pc, this translates to
  radius R = 1.488+-0.021 Rsun (1.4% error).  For the adopted
  Teff(8143+-67K), this translates to luminosity L=8.784+-0.376 Lsun
  or logL = 0.944 +- 0.019 dex.

alf Pic = HD 50241
  A5: Cannon18(standard!),1955MmMtS..12....1W(A5V)
  A5/7III/V: Houk75
 *A6Vn: 1937AnHar.105...45H(A6V),GrayGarrison89,Garrison96
  A7Vn: 1978A&AS...35...75C,Houk75(Garrison)
  A7IV: Levato72
  A8Vn kA6: Gray06
  
  This was the only A6 dwarf in Garrison96's bright star list.  The
  brightest A6Vn star in GrayGarrison89. Only Garrison has classified
  the star as A6Vn, so this may not the best choice for use as a
  possible standard. B-V=0.215+-0.006(Mermilliod91),
  B-V=0.225+-0.019(HIP), V=3.262+-0.009(Mermilliod91),
  plx=33.78+-1.78mas(HIP2) => Mv = 0.905+-0.115. Teffs:
  7349K(diBenedetto98), 7372K(Blackwell98), 7440K(Sokolov95),
  7510K(Stassun18), 7536K(Gray06), 7551K(Zorec12), 7770K(David15) =>
  <Teff> = 7510K.  logg=3.42(Gray06), 3.74+-0.16(David15).

HD 29388 = 90 Tau = HR 1473 (Hyad)
   A4V: Adams35(SB2)
   A5V: 1948ApJ...107..119W(A5n),1952AnAp...15..201C,Slettebak55,Levato72
   A5IV: Palmer68
   A5IV-V: GrayGarrison89
  *A6V: 1940ApJ....91..256T,Morgan65(A6Vn),Cowley69,Abt95
   Am:: Jaschek80

   One of two Hyads classified A6Vn by Morgan65. 
   (B-V)=0.122+-0.005(Mermilliod91), V=4.269+-0.003(Mermilliod91),
   U-B=0.124(Mermilliod91), plx =21.24+-0.56mas(HIP2) => Mv =
   0.905+-0.057(Mermilliod91,HIP2). PASTEL: <Teff> = 8282K(N=5),
   logg=3.87+0.20(Gebran10), [Fe/H]=0.00+-0.22(Gebran10).

HD 79439 = HR 3662 = 18 UMa =
   A5V: Lindblad34(A5),Wilson50,Slettebak55,Cowley69,Levato78
  *A6V: GrayGarrison89,Abt95
   A7V: Barry70(uv metals weak),1980A&AS...40..207C
   A pec: 1978A&AS...35...75C

   V=4.832+-0.012(Mermilliod91), B-V=0.186+-0.008(Mermilliod91).  plx
   = 27.90+-0.20mas(HIP2) => Mv = 2.06+-0.02(Mermilliod91,HIP2).
   PASTEL: Teff=7450+-150K(Elmasli12), Teff=7816+-54K(Zorec12,
   adopted), logg=3.98+-0.20(Elmasli12),
   [Fe/H]=-0.04+-0.20(Elmasli12).

HD 195093 = HR 7829
   A5V:: Abt88
  *A6V: GrayGarrison87,Abt95
   A7V: Cowley69
   A8V: Slettebak63,Levato75

   B-V=0.220(Mermilliod91), V=6.740(Mermilliod91).  Revised Hipparcos
   parallax is *negative* presumably due to binarity: plx =
   -31.22+-11.22 mas(HIP2). plx =14.0626+-0.0532mas(GaiaDR2) => Mv =
   2.48(Mermilliod91,GaiaDR2). Teffs: 7762K(Zorec12),
   7819K(Ammler-vonEiff12), 7872K(GaiaDR2) => <Teff> = 7819K.

HD 2262 = HR 100 = kap Phe 
   A3V: 1955MmMtS..12....1W
   A5IVn: Gray06
   A5Vn: GrayGarrison89
  *A6Vn: Houk78(Garrison)
   A6Vn: Abt95
   A7V: Cucchiaro78
   A7Vn: Evans61,Levato72

   V=3.93(HIP), plx=42.51+-0.69mas(HIP), B-V=0.175+-0.008(HIP),
   del(Mv)=+0.14mag(HIP2). Mv=2.05(HIP2). Teffs: 7670+-240K(Sokolov95),
   7882+-63K(Blackwell98), 7906K(Erspamer03), 8017K(diBenedetto98) =>
   <Teff> = 7894K(N=4). logg=4.17(Erspamer03), [Fe/H]=-0.04(Erspamer03).

HD 12140 = HR 578 = HIP 9295
   A4V: Palmer68
  *A6V: Osawa59,Cowley69,Abt95

   V=6.09(HIP), plx=12.12+-1.11mas(HIP), B-V=0.186+-0.005(HIP),
   del(Mv)=-0.84(HIP2), Mv=1.12(HIP2). Teffs: 7716+-80K(Masana06),
   7834+-54K(Zorec12) => <Teff> = 7775K(N=2).
   
HD 74591 = HR 3469 = 10 Hya = HIP 42931 
   A3IV: Adams35
  *A6V: Palmer68,Cowley69,Abt95

   plx=15.78+-0.90mas(HIP), V=6.13(HIP), B-V=0.200+-0.001(HIP),
   del(Mv)=0.06, Mv=2.08(HIP2).  Teffs: 7689+-76K(Masana06),
   7834+-54K(Zorec12) => <Teff> = 7762K(N=2).
   

# Other Stars

Morgan65 classified two Hyads as A6Vn: HD 28527 & 29388. They have
colors of B-V = 0.170 (HD 28527) and B-V = 0.122 (HD 29388).

HD 28527 = HR 1427 = Cl* Melotte 25 Rg 244 = GJ 170.1 (Hyad) 
   A6Vn: 1940ApJ....91..256T,Morgan65
   A6IV: Cowley69,Barry70(uv metals v.strong)
   A7V: Slettebak55,Cucchiaro80,Abt95
  *kA5hA5mF0(IIIb-): GrayGarrison89
   A8V: Adams35

   One of two Hyads classified as A6Vn by Morgan65 (other was HD
   29388).  (B-V)=0.170+-0.001(Mermilliod91). PASTEL: <Teff> =
   8117K(N=2).  logg=3.98+0.20(Gebran10), [Fe/H]=0.30+-0.20(Gebran10).

HD 77190 = HR 3589
   A5V: 1925sdsl.book.....L
  *A6V: Palmer68,Abt95
   A8Vn: Cowley69

HD 16432 = HR 773 = HIP 12332 
  *A6V: Abt95,Paunzen01
   A7V: Osawa59,Cowley69

   del(Mv)=-1.50mag. Mv=0.38.

HD 144874 = HR 6004
   A5V: Paunzen01
  *A6V: Abt95
   A7V: Cowley69

HD 207235 = HR 8332
   A5V: Abt95
  *A6V: GrayGarrison89
   A7V: Cowley69