K1V

Garrison94 does not list a K1V anchor standard, and MK73 does
not list a K1V dagger standard.

107 Psc (=HD 10476) appears to be the best primary standard. 

MK43 standard:       HD 10476 (=107 Psc) - K1V 
Houk75 standard:     HD 10476 (=107 Psc) - K1V (prim. stan.)
                     HD 184467 - K1V (sec. standard)
Keenan83 standard:   omi^2 Eri (=HD 26965) - K1-V
Keenan85 standard:   omi^2 Eri (=HD 26965) - K1-V 
Corbally86 standard: HD 27771 (=vB 46) - K1V
Keenan88 standard:   HD 10476 (=107 Psc) - K1V
Keenan89 standard:   HD 10476 (=107 Psc) - K1V
Keenan99 standard:   HD 10476 (=107 Psc) - K1V
                     HD 25329 (=GJ 158) - K1Vb_Fe-2 
GrayNstars standard: HD 13445 (=GJ 86A = HR 637) - K1V (but Keenan89 calls K1.5V)
Pecaut13 standard:   HD 10476 (=107 Psc) - K1V 

Skiff08 flags one star as K1V MK standard: HD 10476 (K1V; Keenan89). 

(B-V)(K1V) =  0.894 ; exemplar HD 52698
(B-V)(K1V) =  0.891 ; exemplar HD 750 (metal poor [Fe/H] = -0.3)
(B-V)(K1V) = 0.870 ; median CATSUP d<30pc (N=32)
<B-V>(K1V) =  0.863 ; median for 4 Morgan65 K1V Hyads
(B-V)(K1V) =   0.863 ; deprecated stan. HD 27771 (Hyad)
(B-V)(K1V) = 0.862 ; median SIMBAD K1V d<25pc (N=33)
<B-V>(K1V) =   0.86 ; Vyssotsky63
<B-V>(K1V) =   0.86 ; Fitzgerald70
(B-V)(K1V) =   0.86 ; JohnsonMorgan53
(B-V)(K1V) =   0.86 ; SchmidtKaler82
(B-V)(K1V) =  0.86  ; exemplar 36 Oph B = HR 6401
(B-V)(K1V) = 0.857 ; Koen10 d<25pc median K1V
(B-V)(K1V) = 0.857 ; standards+exemplars trend for [Fe/H]=0.00
(B-V)(K1V) = 0.857 ; xHIP K1V trend for d<50pc interp [Fe/H]=0.00 for -0.3 < [Fe/H] < +0.3
(B-V)(K1V) =  0.854 ; exemplar HD 68788
(B-V)(K1V) =   0.85 ; KenyonHartmann95
<B-V>(K1V) =  0.850 ; 131 HIP d<75pc (+-0.006 sem, +-0.057 stdev)
(B-V)(K1V) =  0.845 ; exemplar HD 97658 (metal poor [Fe/H] = -0.3)
<B-V>(K1V) =  0.845 [+-0.010 sem,+-0.057 stdev]; med. for 35 K1V stars ARICNS
(B-V)(K1V) =  0.844 ; exemplar HD 42286 (metal poor [Fe/H] = -0.5)
<B-V>(K1V) = 0.842 ; 44 Gray01/03/06 (+-0.005 sem, +-0.034 stdev)
(B-V)(K1V) =  0.840 ; exemplar alf Cen B
(B-V)(K1V) = 0.840 ; Median CATSUP d<30pc K1V stars (N=24)
(B-V)(K1V) = 0.836 ; pri. stan. 107 Psc.
(B-V)(K1V) =  0.827 ; exemplar HD 55458 
(B-V)(K1V) =   0.82 ; deprecated stan. HD 13445
(B-V)(K1V) =  0.805 ; exemplar HD 90885 B 
(B-V)(K1V) =   0.784 ; deprecated stan. HD 72673 
=> adopt (B-V)(K1V)  = 0.857 *** [updated 10/14/2020]
=> adopt (Bt-Vt)(K1V)= 0.996
=> adopt (U-B)(K1V)  = 0.524
=> adopt (V-I)(K1V)  = 0.907
=> adopt (V-R)(K1V)  = 0.474
=> adopt (R-I)(K1V)  = 0.433
=> adopt (V-J)(K1V)  = 1.554
=> adopt (V-H)(K1V)  = 1.965
=> adopt (V-Ks)(K1V) = 2.061
=> adopt (H-Ks)(K1V) = 0.096
=> adopt (J-H)(K1V)  = 0.411
=> adopt (V-Hp)(K1V) = -0.144
=> adopt (W1-W2)(K1V)= -0.063
=> adopt (W1-W3)(K1V)= -0.037
=> adopt (W1-W4)(K1V)= -0.015

(Ks-W1)(K1V) = 0.071 ; EEM trend for d<30pc for B-V=0.845
=> adopt (Ks-W1)(K1V) = 0.071 [updated 12/29/2019]


(G-V)(K1V) =  -0.373 ; HD 176051B PM* K1V
(G-V)(K1V) =  -0.274 ; HD 205390 PM* K1V
(G-V)(K1V) =  -0.262 ; HD 103095 PM* K1V_Fe-1.5
(G-V)(K1V) =  -0.260 ; HD_55458
(G-V)(K1V) =  -0.251 ; HD 109200 PM* K1V
(G-V)(K1V) =  -0.250 ; HD 190404 PM* K1V
(G-V)(K1V) = -0.239 ; smoothed fit f(SpT) G9V-M0V
(G-V)(K1V) =  -0.232 ; HD 52698 PM* K1V
(G-V)(K1V) = -0.228 ; pri. stan. 107_Psc (G corrected)
(G-V)(K1V) =  -0.223 ; HD 72673 PM* K1V
(G-V)(K1V) =  -0.185 ; * 36 Oph K1V
=> adopt (G-V)(K1V) = -0.24 [updated 9/21/2021]

(Bp-Rp)(K1V) = 1.0075 ; HD_103095  K1V_Fe-1.5
(Bp-Rp)(K1V) = 1.0102 ; pri. stan. *_107_Psc  K1V
(Bp-Rp)(K1V) = 1.031  ; fit for B-V=0.845
=> adopt (Bp-Rp)(K1V) = 1.01 [updated 5/12/2019]

(G-Rp)(K1V) = 0.558   ; pri. stan. *_107_Psc  K1V (G corrected)
(G-Rp)(K1V) = 0.562   ; fit for B-V=0.845
(G-Rp)(K1V) = 0.5694  ; HD_103095  K1V_Fe-1.5
=> adopt (G-Rp)(K1V) = 0.560 [last updated 8/29/2020]
=> adopt (Bp-G)(K1V) = 0.45  [last updated 8/29/2020; Bp-Rp=1.01, G-Rp=0.56]

Gray01/03/06 list 44 nearby K1V stars. Median HIP colors:
<B-V>(K1V) = 0.842 (+-0.005 sem, +-0.034 stdev; N=44)
<V-I>(K1V) = 0.880 (+-0.003 sem, +-0.028 stdev; N=44)

For Hipparcos K1V stars within 75pc with parallax S/N > 8,
and within 1 mag of the main sequence (N=131):
<B-V>(K1V)   = 0.850 (+-0.006 sem, +-0.057 stdev; N=131)
<V-I>(K1V)   = 0.891 (+-0.005 sem, +-0.059 stdev; N=131)
<V-J>(K1V)   = 1.550 (+-0.010 sem, +-0.104 stdev; N=131)
<V-H>(K1V)   = 1.955 (+-0.014 sem, +-0.136 stdev; N=131)
<V-Ks>(K1V)  = 2.064 (+-0.012 sem, +-0.140 stdev; N=131)
<J-H>(K1V)   = 0.408 (+-0.004 sem, +-0.044 stdev; N=131)
<H-K>(K1V)   = 0.108 (+-0.002 sem, +-0.029 stdev; N=131)
<Bt-Vt>(K1V) = 0.984 (+-0.008 sem, +-0.075 stdev; N=131) 
<V-Vt>(K1V)  =-0.094 (+-0.002 sem, +-0.023 stdev; N=129) 
<B-K>(K1V)   = 2.919 (+-0.017 sem, +-0.184 stdev; N=131)

(U-B)(K1V)   = 0.497 ; HIP d<75pc S/N>8 K1V N=84 (Mermilliod91 photometry)
(U-B)(K1V)   = 0.54  ; JohnsonMorgan53

(g-r)(K1V) = 0.634 ; Jordi06 (V-R)=>(g-r) for V-R=0.463
(g-r)(K1V) = 0.693 ; Bilir05 (B-V)=>(g-r) for B-V=0.840
(g-r)(K1V) = 0.70  ; Covey07 interp K0V-K2V
=> adopt (g-r)(K1V) = 0.69 [updated 10/10/2020]

Teff(K1V) =  4966 +- 53 K  ; vanBelle09
Teff(K1V) = 5042 K ; exemplar HD 42286 (metal poor [Fe/H] = -0.5)
Teff(K1V) = 5071 K ; exemplar HD 750 (metal poor [Fe/H] = -0.3) 
Teff(K1V) =  5080 K ; Schmidt-Kaler82
Teff(K1V) =  5110 K ; GrayCorbally09
Teff(K1V) = 5131 K ; exemplar HD 52698 
Teff(K1V) = 5139 K ; exemplar HD 68788
Teff(K1V) =  5147 +- 14 K ; Boyajian12b (N=1)
Teff(K1V) =  5160 K ; GrayCorbally94
Teff(K1V) = 5161 K ; mean photometric Teff
Teff(K1V) = 5168 K ; smoothed Teff(SpT) trend
Teff(K1V) = 5170 K ; standard+exemplar trend as f([Fe/H]) for [Fe/H]=0.00
Teff(K1V) = 5171 K ; median Teff for N=228 published Teffs for K1V stars
Teff(K1V) = 5196 K ; pri. stan. 107 Psc median Teff ([Fe/H] ~ 0.0)
Teff(K1V) = 5206 K ; Teff for d<30pc [Fe/H]=+-0.1 dex dwarfs from Hinkel17 for B-V=0.842
Teff(K1V) = 5212 K ; exemplar HD 97658 ([Fe/H] = -0.3)
Teff(K1V) =  5230 K ; deprecated stan. HD 27771 
=> adopt Teff(K1V) = 5170 K (logT = 3.713) [updated 10/15/2020]

BCv(K1V) =  -0.270 mag ; Schmidt-Kaler82(fixed typo?,BCv=-0.40 + 0.13 offset)
BCv(K1V) = -0.254 mag ; EEM fit to Casagrande06/08/10 (Teff=5180K)
BCv(K1V) = -0.238 mag ; Flower96(Teff=5180K)
BCv(K1V) = -0.229 mag ; Masana06(Teff=5180K)
BCv(K1V) = -0.223 mag ; Bessell98(ATLAS9,logg=4.5,Teff=5180K)
BCv(K1V) = -0.217 mag ; Casagrande18(Teff=5180K,logg=4.5)
BCv(K1V) = -0.217 mag ; HD 97658 = GJ 3651 (see below) [Fe/H]=-0.32 (Teff=5212K)
BCv(K1V) = -0.201 mag ; Bertone04(Teff=5180K)
BCv(K1V) =  -0.185 +- 0.021 mag ; non-standard GJ 53A (K1V Fe-2) (Pecaut13)
=> adopt BCv(K1V) = -0.23 mag [last updated 12/15/2020, adjusted so that BCv(5772K)=-0.085]

Mv(K1V)  =   6.44  mag ; exemplar HD 55458
Mv(K1V)  =   6.30  mag ; exemplar HD 42286
Mv(K1V)  =   6.23  mag ; exemplar 36 Oph B 
Mv(K1V)  =   6.17  mag ; exemplar 36 Oph A
Mv(K1V)  =  6.11 mag  ; V-Ks=2.016, Sarajedini04 V-Ks vs. Mv
Mv(K1V)  =    6.1  mag ; GrayCorbally09
Mv(K1V)  =    6.1  mag ; Schmidt-Kaler82
Mv(K1V)  =   6.09  mag ; exemplar HD 97658 ([Fe/H] = -0.3)
Mv(K1V)  =  6.09 mag  ; median Mv K1V d<20pc XHIP
Mv(K1V)  =  6.06 mag  ; V-K=2.016 => EEM fit to Reid CNS3 data
Mv(K1V)  =  6.02  mag ; median SIMBAD K1V d<25pc (N=33)
Mv(K1V)  =  6.00  mag ; Koen10 d<25pc median K1V
Mv(K1V)  =  6.00  mag ; SIMBAD d<20pc trend for K dwarfs for V-Ks=2.029 (M_Ks=3.97)
Mv(K1V)  =  5.96  mag ; V-Ks=2.016 EEM fit to Jao16 calibration
Mv(K1V)  = 5.95  mag ; interp K0V(B-V=0.816,Mv=5.78) & K2V(B-V=0.884,Mv=6.07)
Mv(K1V)  =   5.94  mag ; exemplar HD 90885 B 
Mv(K1V)  =  5.89  mag ; V-Ks=2.016 EEM MS data
Mv(K1V)  =  5.88  mag ; B-V=0.84 => Mv(Wright05)
Mv(K1V)  =   5.88  mag ; exemplar HD 52698 = GJ 259
Mv(K1V)  =  5.87  mag ; CATSUP -0.1<[Fe/H]<0.1 d<30pc for B-V=0.840
Mv(K1V)  =   5.87  mag ; exemplar HD 68788
Mv(K1V)  =   5.86  mag ; exemplar alf Cen B
Mv(K1V)  =  5.86  mag ; Gray01/03/06 dwarfs, xHIP B-V/Mv, Gaspar16 |[Fe/H]|<0.05 "solar": fit for B-V=0.84
Mv(K1V)  =  5.84  mag ; B-V=0.84 => EEM fit to d<25pc FGK SIMBAD
Mv(K1V)  =   5.83  mag ; pri. stan. HD 10476 = 107 Psc ([Fe/H] ~ -0.04)
Mv(K1V)  =    5.70 mag ; Wegner07
=> adopt Mv(K1V)   = 5.95  mag [updated 12/15/2020] 
=> adopt M_G(K1V)  = 5.71  mag [updated  9/21/2021] (Mv=5.95, G-V=-0.24)
=> adopt M_Ks(K1V) = 3.889 mag [updated 12/15/2020] (Mv=5.95, V-Ks=2.061)

M_G(K1V) = 5.827 ; SIMBAD d<20pc trend for V-Ks=2.061

M_Ks(K1V) = 3.99 ; median d<25pc N=16 

logL(K1V) = -0.352 dex ; pri. stan. HD 10476 = 107 Psc (Boyajian13)
logL(K1V) = -0.392 dex ; Mv=5.95, BCv=-0.23 mag => Mbol = 5.720
logL(K1V) = -0.49+-0.07 dex ; ecl. binary 1SWASP_J093010.78+533895.5A (Koo14)
=> adopt logL(K1V) = -0.392 dex [updated 12/15/2020]
=> adopt Mbol(K1V) =  5.720 mag [updated 12/15/2020]

Rad(K1V) = 0.8101 +- 0.0045 Rsun ; pri. stan. HD 10476 = 107 Psc (Boyajian13) ([Fe/H]~-0.02)
Rad(K1V) = 0.8051 +- 0.0035 Rsun ; Boyajian12b (N=1)
Rad(K1V) = 0.798 Rsun ; halfway between radius for K0V and K2V
Rad(K1V) = 0.797 Rsun ; Teff=5160K,  logL=-0.392
Rad(K1V) = 0.757 +- 0.008 Rsun ; ecl. binary 1SWASP_J093010.78+533895.5A (Koo14)
=> adopt Rad(K1V) = 0.797 Rsun [updated 12/15/2020]

Mass(K1V) = 0.873 Msun ; EEM Mv vs. Mass fit for binaries (Mv=5.9)
Mass(K1V) = 0.864 Msun ; Eker18 ML calibration for logL=-0.372
Mass(K1V) = 0.849 Msun ; EEM logL vs. Mass fit for binaries (logL=-0.372)
Mass(K1V) = 0.848 Msun ; Eker15 calibration for logL=-0.372
Mass(K1V) = 0.766+-0.014 Msun ; ecl. binary 1SWASP_J093010.78+533895.5A (Koo14)
=> adopt Mass(K1V) = 0.86 Msun [last updated 10/23/2019]

# No standard

JM53, Wilson62, Morgan65, KeenanMcNeil76, Keenan80, Keenan83, Keenan85
do not list a K1V standard

# Primary Standard

HD 10476 = 107 Psc = HR 493 = GJ 68 (J0142+2016)
  G9V: Adams35
  K0V: Bidelman85(K0),Gray03,Wilson62
  K1-V: Keenan85
 *K1V: Keenan41,MK43,JM53(non-stan),Morgan53,Jaschek64(all),Jaschek78(JM53),Hoffleit82(BSC),Keenan89,Keenan88,Keenan99,Houk,Gray06,Pecaut13

  Excellent standard of near solar metallicity, which is fortunate as
  there really aren't other good standard stars for this
  subtype. Similar activity to Sun (logR'HK = -4.91). B-V =
  0.836+-0.008 (HIP,Mermilliod91),
  V=5.24(HIP). plx=131.4903+-0.1515mas (GaiaDR2) => Mv=5.83. As of
  8/29/2020, PASTEL compendium lists 26 Teffs with median Teff =
  5198K, and 17 [Fe/H]s with median [Fe/H] = -0.04, median
  logg=4.50. Notably, Ramirez12 derives [Fe/H]=-0.02+-0.04. GaiaDR2:
  G=4.9697 0.0034 (uncorrected). GaiaDR2: E(BR/RP)=1.151,
  Bp-Rp=1.0102, Bp-G=0.4939, G-Rp=0.5163.  corrected G only:
  G_corr=5.012, Bp-G(cor)=0.452, G-Rp(cor)=0.558.  G-V = 5.012 - 5.24
  = -0.228, M_G=5.606+-0.003. Mv=5.834. Activity:
  logR'HK=-4.912. Ages: 5.0, 6.3 Gyr(Mamajek08), 5.24Gyr(Isaacson10),
  4.1+-0.9Gyr(Ramirez12), 4.27(2.92-10.34)Gyr(Ramirez12),
  4.99Gyr(Ballering13), 5.3Gyr(Boyajian13).  Yee17: Teff=5242+-12K,
  R=0.810+-0.004Rsun, logg=4.57+-0.02, [Fe/H]=-0.02+-0.10,
  Mass=0.88+-0.04Msun, log(age/yr)=9.51+-0.42. Boyajian13:
  R=0.8108+-0.0045Rsun, fbol=(25.1400+-0.1100)e-8 erg/s/cm2,
  L=0.4443+-0.0039Lsun => logL = -0.3523+-0.0038 dex, Teff=5242+-12K,
  age=5.3Gyr, Mass=0.862Msun.

# Exemplars

HD 55458 = HIP 34950
 *K1V: Adams35,Roman55,Gray03

  All 3 classifications in Skiff compendium are K1V, however the star
  appears to be fairly metal poor [Fe/H] ~ 0.4.
  V=8.402+-0.004(Mermilliod91), B-V=0.827+-0.016(Mermilliod91),
  U-B=0.382+-0.018(Mermilliod91). Mv=6.44. Only PASTEL value is Teff
  from Casagrande11: Teff=5119K(Casagrande11). [Fe/H] =
  -0.46(Holmberg09), -0.40+-0.06(Gaspar13), -0.33(Casagrande11).

alf Cen B = HD 128621 = HR 5460 = HIP 71681 = GJ 559B = Toliman
  K2IV C2 1: Gray06
 *K1V: Moore32(K1),Hoffleit37,Kuiper38(K1),Houk75(Garrison),Ayres76,Hoffleit82(BSC),Garrison96
  K5V: PickeringCannon1897(K5),Cannon20(K5),Adams35
  K0V: Kamper78,England80

  Garrison96 lists alf Cen B as the only bright K1V star among the
  brightest ~300 stars in the sky (V<3.55mag), although it is somewhat
  metal-rich [Fe/H] ~ +0.2.  I don't understand the meaning of the
  Gray06 type.  Bessell83
  (http://articles.adsabs.harvard.edu/full/1983PASP...95..480B) quotes
  V(B) = 1.335, B-V(B)=0.840, V-R(B)=0.474, R-I(B)=0.404,
  V-I(B)=0.878. Mv=5.86. [Fe/H] = +0.24+-0.03(Zhao18).
  Teff = 5231+-21K(Kervella17). 

HD 52698 = GJ 259 
  K0Ve: Evans57
 *K1V(k): Gray06,Torres06(K1V),Houk88(K1V)

  Tight binary: WDS reports sep 0.5" epoch 2016 (mag1=6.50,
  mag2=11.10). Kervella19 reports tangential velocity anomaly
  802.16+-12.64 km/s.  (B-V)=0.894+-0.011(Mermilliod91), V=6.71(HIP),
  Mv=5.88.  PASTEL median values: Teff = 5131K(N=4), [Fe/H]=0.16(N=4),
  logg~4.3 (large scatter; N=4).

HD 68788 = HIP 40848 
 *K1V: Adams35,Roman55,Cowley67
  K0: Bidelman85

  (B-V)=0.854+-0.009(Mermilliod91), V=8.380(Mermilliod),
  U-B=0.530(Mermilliod91), Mv=5.87. PASTEL median values: Teff =
  5139K(N=4), logg=4.51(N=2), [Fe/H]=-0.10(N=2).

HD 750 = HIP 934 = 2MASS J00113577-5728213
  *K1V: Houk75,Gray06

   Only two published SpTs are K1V.  plx = 26.9188 0.0294
   mas(GaiaDR2).  V=9.04(HIP), B-V=0.891+-0.020(HIP), V-I=0.90+-0.01.
   Ks=6.993(2MASS). V-Ks = 9.04-6.993 = 2.047. Mv=6.55.  Teffs:
   5000K(GaiaDR2#1), 5060K(Sousa08), 5069K(Tsantaki13),
   5073K(Casagrande11), 5146K(Masan06), 5155K(GaiaDR2#2) => <Teff> =
   5071K. PASTEL [Fe/H]=-0.295(N=2), logg=4.36(N=2).

HD 42286 = HIP 28898 = 2MASS J06060351-5932353
   K0V: Evans61
  *K1V: Houk75,Gray06

   V=8.45(HIP), V=8.454+-0.005(Mermilliod91), B-V=0.844+-0.003(HIP),
   B-V=0.842+-0.007(Mermilliod91), V-I=0.89+-0.00(HIP).  plx = 37.0627
   0.0543 mas(GaiaDR2). Mv=6.299+-0.006(Mermilliod91,GaiaDR2).
   Ks=6.264+-0.020(2MASS), V-Ks = 8.454 - 6.264 = 2.19.  Teffs:
   5000K(GaiaDR2#1), 5023+-50K(Casagrande11), 5060K(GaiaDR2#2),
   5076+-39K(Masana06) => <Teff> = 5042K.  [Fe/H]=-0.5(GaiaDR2),
   logg=4.5(GaiaDR2).

HD 90885 B = WDS J10283-5234B = 2MASS J10281791-5233402
  *K1V: Torres06,Gray06
   K2/3III: Houk78

   Component A is 5.9" away (Gray06 classifies primary as K0.5V(k)).
   plx = 29.9647 0.0439 mas (GaiaDR2).  V=8.56(Tycho-1),
   B-V=0.805+-0.024(Tycho-1), Ks=6.574+-0.031(2MASS).  Teff =
   5174K(GaiaDR2). Mv=5.94.

HD 97658 = GJ 3651 = HIP 54906 = SPOCS 482 = 2MASS J11143316+2542374
   G7V: Moore50
  *K1V: Gray03,1956PDDO....2..105H,Strassmeier00(K1)

   Metal-poor exoplanet host star - transiting sub-Neptune HD97658b
   (R=2.4Re; Guo20) with diameter measurement. V=7.76(HIP),
   V=7.760(Mermilliod91), V=7.77(Tycho), B-V=0.845+-0.015(HIP),
   B-V=0.845(Mermilliod91), plx = 46.3494 0.0541 mas (GaiaDR2) => Mv=
   6.09. Teffs: 5120K(Brewer16), 5136K(Mishenina12,Mishenina08),
   5137K(Mortier13), 5148K(Valenti05), 5157K(Luck17),
   5190K(Bonfanti15), 5211K(Kotoneva06), 5217K(Maldonado15),
   5222K(Bermejo13), 5287K(daSilva15) => <Teff> ~ 5170K.
   <[Fe/H]>=-0.32(N=6), <logg>=4.50(N=6).  Prot=34+-2d(Guo20),
   Pcyc=9.6yr. Ellis21(2021AJ....162..118E) derived precise
   measurements from CHARA observations/analysis: R=0.728+-0.008Rsun,
   fbol = (2.42+-0.05)e-8 erg/s/cm2 (IAU2015 scale => mbol =
   7.5430+-0.0224), Teff=5212+-43K. Inferred bolometric correction BCv
   = mbol - V = (7.5430+-0.0224) - 7.760 = -0.217.
   


# Deprecated Standards

HD 184467 = GJ 762.1 = Cin 20 1157 (J1931+5835)
  K0V: Bartaya83
  K1V: Roman55,Jaschek64(all),Jaschek78(Roman55),Houk(sec.stand.)
 *K2V: Wilson62,Bidelman85,Keenan89,Gray03
  K4V: Keenan88
  K5V: Joy35

  Type has floated around too much in the literature, although most
  recently Keenan and Gray settled on K2V.

HD 27771 = Cl Melotte 25 46 = HIP 20492
  G5: Cannon
  G8: Wilson48,Ramberg41(G8V)
  K0V: Cannon49(K0),Wilson62
 *K1V: Morgan65,Corbally86(stan,Morgan65)

  Not much pedigree as a standard (just used by Corbally apparently).
  (B-V)=0.863+-0.004(Mermilliod91). PASTEL mean Teff = 5230K(N=4),
  [Fe/H]=+0.075(N=2), logg=4.55(N=2).

HD 72673 = HR 3384 = LHS 249 (J0832-3130)
  G5: Cannon
  G8V: Adams35
  G9V: Bidelman85(G9),Gray06
  K0V: Evans61,Jaschek64(all),Houk82,Hoffleit91
 *K1V: Keenan89,Keenan99

  Only Keenan it called K1V, but Gray recently classifies G9. Little
  agreement, probably due to low metallicity. Extremely blue compared
  to other K1Vs ((B-V)=0.784+-0.005). 14th brightest "K0V" in Bright
  Star Catalog(Hoffleit91).  PASTEL: <Teff>=5257K(N=16),
  <logg>=4.60(N=13), <[Fe/H]>=-0.38.

HD 13445 = HR 637 = LHS 13 (J0210-5049)
  K0V: Evans57
  K1V: 1943HarCi.449....1H,Gray06,Houk78
 *K1.5V: Keenan89,Keenan99

  Houk & Gray agree on K1V, but Keenan called it K1.5V standard.  Has
  DQ6 white dwarf companion 2" away.

# Variant Standard

HD 25329 = GJ 158
  K1Vb Fe-2: Keenan99

# Other Stars

Morgan65 classified 4 Hyads as K1V: HD 27771 (B-V=0.855; HIP), 28462
(B-V=0.865; HIP), 28783 (B-V=0.881; Mermilliod91), 29159 (B-V=0.86;
Hanson03). Median <B-V> = 0.863.

RECONS list shows Alf Cen B is the nearest K1V star, followed by GJ
166A (omi^2 Eri; J0415-0739).

36 Oph A = HR 6402 = HD 155886 = GJ 663A
   K0V: 1923LicOB..10..169L(K0),Evans57(K0Ve),Corbally84
  *K1V: Adams35,Abt81
   K1.5V(k): Gray06(probably unresolved)
   K2V: Joy49,Bidelman85(K2)
   K2:III:: Houk82

   Median type is K1V, same as for 36 Oph B.  BSC: V=5.07, B-V=0.85,
   U-B=0.53. plx = 167.8221+-0.1556mas(GaiaDR2).  Mv =
   6.19. Essentially an equal brightness binary:
   delta(Hp)=0.011+-0.010(HIP), the Worley01 photometric difference
   catalog has several delta(mag) estimates, all between 0.00 and
   0.05.  Taking delta(Hp)=delta(V), then then the Mermilliod91
   unresolved Vmag (4.323+-0.015) translates to V(A)=5.070+-0.016,
   V(B)=5.081+-0.019.  plx(A)=167.8221+-0.1556mas(GaiaDR2),
   plx(B)=167.7764+-0.2210mas(GaiaDR2) => wt mean
   plx(AB)=167.8070+-0.1272mas.  Mass: 0.75+-0.04Msun(Irwin96),
   0.75+-0.06Msun(Luck17), 0.794Msun(Anders19), 0.824Msun(Eker18
   calibration for logL below), 0.83Msun(Tokovinin18), 0.840Msun(EEM
   Mv fit). Tokovinin19 and WDS Orbit6 seems to prefer the Irwin96
   solution#2 orbit with P=470.90yr, e=0.916,a=13.0",inc=99.79.
   Luminosity: 0.33204+-0.00850Lsun(Stassun19),
   0.350+-0.001Lsun(GaiaDR2). EEM: logL=-0.490+-0.006.  PASTEL: half
   dozen values, but estimate with uncertainties on parameters is
   Heiter03: Teff=5100+-50K, logg=4.30+-0.05, [Fe/H]=-0.30+-0.07,
   though others get logg=4.6. Luck17: Teff=5103K, logg=4.64,
   [Fe/H]=-0.23.  Rad = 0.729Rsun (for logL=-0.490+-0.006,
   Teff=5100+-50K).

36 Oph B = HR 6401 = HD 155885 = GJ 663B
   G8V:: 1943HarCi.449....1H
   K0V: 1923LicOB..10..169L(K0),Abt84,Corbally84
  *K1Ve: Evans59, Bidelman85(K1),Hoffleit91(K1V)
   K1.5V(k): Gray06
   K2:III:: Houk82
   K3V: Adams35

   Not good agreement on type. Median is K1V. Mermilliod91 only
   provides unresolved/combined B-V=0.859+-0.007, V=4.323+-0.015,
   U-B=0.494+-0.017. Essentially an equal brightness binary:
   delta(Hp)=0.011+-0.010(HIP), the Worley01 photometric difference
   catalog has several delta(mag) estimates, all between 0.00 and
   0.05. Taking delta(Hp)=delta(V), then then the Mermilliod91
   unresolved Vmag (4.323+-0.015) translates to V(A)=5.070+-0.016,
   V(B)=5.081+-0.019. Corbally84 provides resolved photometry: V=5.11,
   B-V=0.86, U-B=0.53 (also in BSC, Hoffleit91).  plx =
   167.776+-0.221mas. Mv=6.23.  Mass: 0.75+-0.04Msun(Irwin96),
   0.76+-0.11 Msun(Luck17),
   0.788Msun(Anders19), 0.823Msun(Eker18 calib for logL below),
   0.83Msun(Tokovinin18), 0.836Msun(EEM Mv fit) => adopt 0.823Msun.
   Given the tiny delta(V), the masses should only differ by 0.001
   Msun, i.e. identical masses for all practical purposes.
   Luminosity: 0.32747+-0.00848Lsun(Stassun19),
   0.347+0.001-0.002Lsun(GaiaDR2).  PASTEL: half dozen publications,
   but best with uncertainties is Ramirez13: Teff=5087+-44K,
   logg=4.58+-0.02, [Fe/H]=-0.25+-0.04. Luminosity(EEM):
   logL=-0.494+-0.009. For Teff=5087+-44K, then Rad=0.729+-0.015Rsun.
   Hence the components seem to be identical radius as well.

HD 109200 = HIP 61291
  G5: Cannon
  K0V: Jaschek78(Evans57),Jaschek64(3 refs = all)
  K1V: Houk75,Gray06

  Houk & Gray agree on type.

HD 124106 = HIP 69357 (J1411-1236)
  K0V: Wilson50
 *K1V: Houk88,Gray06(K1V(k))
  K2V: Upgren72
  G5: Cannon

HD 177996
  K1Ve: Eggen61,Houk78(K1V),Lu83(K1V)
  K1.5V(k): Gray06

HD 220182 = BD+43 4445
 *G9V: Bidelman85(G9),Gray03
  K1V: Adams35,1952IzKry...9...82G,Cowley67

HD 103095 = LHS 44 = HIP 57939  = Groombridge 1830
  G5V: Upgren62
  sdG5: Adams35
  G7V+: Keenan53
  G7Vp: Keenan40
  G8V: MK43
  G8V:p: Bidelman85
  G9V: Schild73
  G9/K0VgG2mG7/8: (Skiff08,unpub.)
  G9VgG2mG7: Abt86
 *K1V Fe-1.5: Gray03

  Very metal poor star, only included here because it is a very nearby, bright G/K dwarf.

HD 6569 = UGP 16
   K1V: Houk88,Torres06
   K2V: Upgren72,McNeil86

   Evenly split, adopt K1.5V. 

HD 9054
   K1V: Houk75,Torres06
   K2V+Vk: Gray06

HD 18134 = VZ Hor
  *K1Ve:: Houk75(Eggen84),Torres06(K1V)

   Torres06 says it is SB; VSX calls it a BY Dra system.  Kiraga12
   shows it to be a saturated X-ray emitter (logLx/Lbol = -3.08) and
   measured photometric period 2.508 day, Vmag amplitude 0.042
   day. plx = 24.9213 0.0299 mas (GaiaDR2). GaiaDR2 shows CPM
   companion about 24.0" away (WDS J02519-6137), likely late M dwarf.
   Eggen84: Hyades supercluster member? 
  
HD 17970 = GJ 3187 = HIP 13388 = 2MASS J02521965-3327024
   K1V: Evans66,Houk82
  *K2V: Gray06
   K3: Bidelman85

   plx = 39.2808 0.0322 mas(GaiaDR2).

HD 26965 = omi^2 Eri = GJ 166A = HR 1325 (J0415-0739)
   G9V: Abt85
   K0V: Wilson62,Morgan65,Keenan99
  *K0.5V: Keenan88,GrayNstars(stan),Gray06
   K1-V: Keenan83,Keenan85
   K1V: Roman55,Bidelman85(K1),Gray03

   Morgan65 calls omi2 Eri the K0V "fundamental classification
   standard". Keenan migrated its type blueward over two decades, going
   from K1-V (1983,1985) to K0.5V (1988) to K0V (1999). PASTEL medians:
   <Teff> = 5153 K (N=25), <[Fe/H]> = -0.28
   (N=18). B-V=0.816+-0.005(Mermilliod91),
   U-B=0.446+-0.009(Mermilliod91), V=4.424+-0.012(Mermilliod91).
   Mv=5.94.
  
HD 31027 AB = UGP 95 = WDS J04496-5353 = HIP 22431
  *K1V: Houk75,Gray06
   K4V: Upgren72

   WDS binary, sep=3.2", mag1=8.28, mag2=8.77.  Malkov12 lists orbital
   period = 868.05+-19.71 yr.  Probably not ideal exemplar as close
   binary.  V=7.64(HIP), B-V=0.846+-0.002(HIP), V-I=0.86+-0.00(HIP).
   Ks=5.648+-0.049. V-Ks=1.992.

HD 85228
   K1V: Evans64,Houk78
  *K2V CN+0.5: Gray06

HD 85994 AB = UGP 214
  *K1V: Houk82,Torres06
   K2V: Upgren72

   AB is 0.9" binary in WDS, and C component 6" away (M1V, V=12.5).
   WDS lists component magnitudes V(A)=8.98, V(B)=9.68.  For
   delta(mag)=0.7, the HIP unresolved Vmag (8.56) splits to V(A)=9.02,
   V(B)=9.72, in good agreement with WDS. B-V=0.844+-0.028(HIP), plx =
   24.6287 0.7902 mas (GaiaDR2).  Companion C plx = 23.9211 0.0507 mas
   (GaiaDR2). 

HD 87884 = Regulus B = GJ 9316 BC
   K0V: Slettebak63(K0Vb),Murphy69,Gahm83(K0Ve)
  *K1V: Adams35,Lutz77
   K2V: Bidelman85(K2),Wilson62,Montes01

   Young active binary (2.1" in WDS), with poor agreement among
   classifications. WDS lists magnitudes 8.24 and 13.2. Gahm notes
   strong emission-lines.  Primary is bright B8IVn star Regulus 176"
   away.  plx = 41.2114 0.0777 mas (GaiaDR2).

HD 104006
   K1V: Evans61,Houk78

HD 109200
   K1V: Houk75,Gray06

HD 124752
   K1V: Wilson50,Levato78

HD 125455
   K1V: Adams35,Cowley67

HD 131119
   K1V: Houk82,Torres06

HD 131511
   K1V: Adams35,Torres06

HD 132142
   K1V: Roman55,Cowley67

HD 144088
   K1V: Adams35,Gray06

HD 144628
   K1V: Drilling68,Gray06

HD 148704
   K1V: Adams35,Gray06

HD 155886
   K1V: Adams35,Abt81

HD 190404
   K1V: Roman55,Gray03

HD 200968
   K1V: Adams35,Evans66

HD 217487
   K1V: Houk78,Gray06

HD 218483
   K1V: Houk78,Gray06

HD 221354
   K1V: Yoss61,Duflot61

HD 222335
   K1V: Evans64,Houk82


# COLOR TRENDS 

xHIP catalog - including Gray classifications, various [Fe/H] estimates, and B-V:

HD#         plx  [Fe/H] eFeH B-V   ref_SpT  
HD_109200_  61.82 -0.27 0.02 0.836 2006AJ....132..161G      
HD_97658_   47.36 -0.26 0.03 0.845 2003AJ....126.2048G      
HD_130042_  40.11 -0.16 0.08 0.836 2006AJ....132..161G      
HD_112099_  37.41 -0.14 0.08 0.853 2003AJ....126.2048G      
HD_124106_  42.76 -0.14 0.03 0.865 2006AJ....132..161G      
HD_17190_   38.59 -0.11 0.04 0.840 2003AJ....126.2048G      
HD_175073_  41.31 -0.11 0.08 0.857 2006AJ....132..161G      
HD_82443_   56.20 -0.10 9.99 0.779 2006AJ....132..161G      
HD_113449_  46.10 -0.09 9.99 0.847 2003AJ....126.2048G      
HD_217487_  32.76 -0.06 0.08 0.827 2006AJ....132..161G      
HD_221851_  42.00 -0.04 9.99 0.845 2003AJ....126.2048G      
HD_224789_  33.48 -0.04 0.03 0.863 2006AJ....132..161G
HD_20165_   44.15 -0.03 0.03 0.861 2003AJ....126.2048G      
HD_10476_  132.76 -0.02 9.99 0.836 2006AJ....132..161G
HD_59747_   50.60 -0.02 9.99 0.863 2003AJ....126.2048G      
HD_144088_  44.25  0.06 0.08 0.850 2006AJ....132..161G      
HD_114783_  48.78  0.11 0.01 0.930 2003AJ....126.2048G      
HD_130215_  39.73  0.11 9.99 0.870 2003AJ....126.2048G      
HD_139341_  44.83  0.22 0.03 0.906 2003AJ....126.2048G

solar [Fe/H] B-V estimate => ~0.860
flat      => 0.8593
linear    => 0.8642
quadratic => 0.8576