K7V Garrison94 does not list a K7V anchor standard, but MK73 lists 61 Cyg B as the K7V dagger standard. Given 61 Cyg B = GJ 820B's long heritage (JM53,MK73,Boeshaar76,Keenan88) and recent use (Kirkpatrick91,GrayAtlas,Henry02) as the K7V standard, it should probably be considered the best K7V standard. KeenanMcNeil76 states "Between K5 and M0 we now use K7 for stars of all luminosity classes." Keenan84 does not list K7 as a full subtype like K5 and M0, and "other possible subdivisions are utilized only for interpolation whenever we think that we can classify accurately enough to justify their use. Thus when we call a star G3 we mean only that it is closer to G2 than to G5." Note that Hawley97 considers both 61 Cyg B and GJ 380 to be 'K5', so perhaps many K5 stars in their survey could be ~K7V? JM53 standard: 61 Cyg B (=HD 201092) - K7V BD+56_1458 (=GJ 394) - K7V Wilson62 standard: 61 Cyg B (=HD 201092) - K7V [from JM53] Abt68 standard: 61 Cyg B (=HD 201092) - K7V MorganKeenan73 standard: 61 Cyg B (=HD 201092) - K7V (dagger standard) Boeshaar76 standard: GJ 380 - K7 (Plate II standard) KeenanMcNeil76 stan.: 61 Cyg B (=HD 201092) - K7V Keenan80 standard: 61 Cyg B (=HD 201092) - K7V Keenan83 standard: 61 Cyg B (=HD 201092) - K7V Corbally86 standard: 61 Cyg B (=HD 201092) - K7V Keenan88 standard: 61 Cyg B (=HD 201092) - K7V Keenan89 standard: 61 Cyg B (=HD 201092) - K7V Kirkpatrick91 standards: 61 Cyg B (=GJ 820B) - K7V (primary) GJ 380 - K7V (primary) GJ 338 B - K7V (secondary) GJ 764.1 - K7V (secondary) GJ 265 A - K7V (secondary) GJ 786 - K7V (secondary) GJ 748.2 A - K7V (secondary) GJ 430 - K7V (secondary) Henry02 standards: GJ 34 B - K7.0V (from Henry94) GJ 185 AB - K7.0VJ (from Henry94) GJ 338 B - K7.0V (from Kirkpatrick91) GJ 380 - K7.0V (from Kirkpatrick91) GJ 673 - K7.0V (from Henry94) 61 Cyg B (GJ 820 B) - K7.0V (from Kirkpatrick91) GrayAtlas standard: 61 Cyg B (=HD 201092) - K7V GrayNstars standard: 61 Cyg B (=HD 201092) - K7V GJ 185 - K7.0VJ Pecaut13 standard: GJ 673 - K7V Newton14 standard: GJ 394 (=HD 237903) - K7V Kirkpatrick16 standard: 61 Cyg B (=Gl 820B) - K7V Henry02 lists 5 K7V standards and one "K7VJ" (joint; SB; GJ 185) Skiff08 flags only one star as K7V MK standard: HD 201092 (Keenan89) (B-V)(K7V) = 1.401 ; exemplar GJ 56.3B (B-V)(K7V) = 1.393 ; exemplar GJ 34B (eta Cas B) (B-V)(K7V) = 1.386 ; exemplar GJ 1075 (B-V)(K7V) = 1.38 ; KenyonHartmann95 (B-V)(K7V) = 1.372 ; non-standard GJ 571.1 (B-V)(K7V) = 1.372 ; median SIMBAD K7V d<25pc (N=67) (K7V) = 1.37 ; 6 Hyads in Wilson62 (K7V) = 1.37 ; Vyssotsky63 (B-V)(K7V) = 1.37 ; JohnsonMorgan53 (B-V)(K7V) = 1.367 ; exemplar GJ 710 (B-V)(K7V) = 1.362 ; median Koen10 d<25pc K7V (B-V)(K7V) = 1.359 ; sec. stan. GJ 673 (B-V)(K7V) = 1.352 ; ter. stan. GJ 394 (B-V)(K7V) = 1.35 ; median for N=54 K7Vs within 30 pc (Hinkel17) (B-V)(K7V) = 1.346 ; exemplar GJ 1267 (K7V) = 1.341 ; 30 Gray01/03/06 (+-0.017 sem, +-0.063 stdev) (B-V)(K7V) = 1.336 ; exemplar GJ 455.1 = HD 105065 (B-V)(K7V) = 1.335 (+-0.010 sem,+-0.058 stdev); med. for 40 K7V stars ARICNS (K7V) = 1.33 ; Fitzgerald70 (B-V)(K7V) = 1.33 ; Schmidt-Kaler82 (B-V)(K7V) = 1.326 ; ter. stan. GJ 380 (B-V)(K7V) = 1.321 ; exemplar GJ 773 = HD 188807 (B-V)(K7V) = 1.320 ; ter. stan. GJ 265 A (B-V)(K7V) = 1.320 ; sec. stan. GJ 786 (K7V) = 1.32 ; Bessell79 (B-V)(K7V) = 1.32 ; Bessell91 "old disk" (B-V)(K7V) = 1.318 ; exemplar GJ 798 (B-V)(K7V) = 1.309 ; prim. stan. 61 Cyg B (B-V)(K7V) = 1.30 ; Johnson66 (K7V) = 1.282 ; Crawford76 (K7V) = 1.269 ; 87 HIP d<75pc (+-0.015 sem, +-0.103 stdev) (B-V)(K7V) = 1.257 ; non-stan. HD 204587 (B-V)(K7V) = 1.206 ; ter. stan. GJ 748.2 A (poor value) => adopt (B-V)(K7V) = 1.34 [updated 7/19/2020] (U-B)(K7V) = 1.188 ; HIP d<75pc S/N>8 K7V N=80 (U-B)(K7V) = 1.22 ; Johnson66 (U-B)(K7V) = 1.27 ; JohnsonMorgan53 (V-Ic)(K7V) = 1.731 (+-0.025 sem, +-0.128 stdev; Koen10 N=48) (V-I)(K7V) = 1.7 ; Hawley96 (V-Ic)(K7V) = 1.64 ; exemplar GJ 1075 (V-I)(K7V) = 1.60 ; Bessell91 "old disk" (V-Ic)(K7V) = 1.571 (+-0.032 sem, +-0.105 stdev; Gray01/03/06 N=30) (V-Ic)(K7V) = 1.53 ; Bessell79 (V-Ic)(K7V) = 1.519 ; trend, from V-Ks=3.35 (V-Ic)(K7V) = 1.421 (+-0.026 sem, +-0.199 stdev; HIP d<75pc S/N>8 N=87) => adopt (V-Ic)(K7V) = 1.519 [updated 8/13/2020] (K7V) = 0.74 (R-I)(K7V) = 0.77 ; Bessell91 "old disk" (V-R)(K7V) = 0.83 ; Bessell91 "old disk" (K7V) = 2.908 (+-0.049 sem, +-0.173 stdev; Gray01/03/06 N=30) (K7V) = 2.90 (+-0.31 stdev) ; Lepine12 (G-J)(K7V) = 1.890 ; Bentley18 (G-Ks)(K7V) = 2.737 ; Bentley18 (Ks-W2)(K7V) = 0.060 ; Bentley18 (W1-W2)(K7V) = -0.031 ; Bentley18 (Ks-W1)(K7V) = 0.091 ; Bentley18 (Ks-W1)(K7V) = 0.110 ; EEM fit for d<30pc SIMBAD stars, trend for V-Ks=3.33 => adopt (Ks-W1)(K7V) = 0.110 [updated 12/29/2019] (V-Ks)(K7V) = 3.026 ; ter. stan. GJ 748.2 A (V-K)(K7V) = 3.16 ; Bessell91 "old disk" (K7V) = 3.161 (+-0.039 sem, +-0.308 stdev; HIP d<75pc S/N>8 N=87) (V-Ks)(K7V) = 3.217 ; sec. stan. GJ 786 (V-Ks)(K7V) = 3.229 ; non-stan. HD 204587 (V-Ks)(K7V) = 3.277 ; exemplar GJ 773 (V-Ks)(K7V) = 3.294 ; ter. stan. GJ 764.1 B (V-Ks)(K7V) = 3.329 ; exemplar GJ 1267 (V-Ks)(K7V) = 3.330 ; ter. stan. GJ 394 (V-Ks)(K7V) = 3.355 ; exemplar GJ 798 (V-Ks)(K7V) = 3.359 ; ter. stan. GJ 265 A (V-Ks)(K7V) = 3.367 ; trend for K dwarf standards/exemplars for K7V (V-K)(K7V) = 3.375 ; pri. stan. 61 Cyg B (Alonso96 Kmag, not 2MASS) (V-Ks)(K7V) = 3.375 ; exemplar GJ 455.1 = HD 105065 (V-Ks)(K7V) = 3.379 ; exemplar GJ 710 (V-Ks)(K7V) = 3.396 ; sec. stan. GJ 673 (see below) (V-Ks)(K7V) = 3.485 ; exemplar GJ 56.3 B (V-K)(K7V) = 3.5 ; Hawley96 (V-Ks)(K7V) = 3.502 ; non-stan. GJ 571.1 (unresolved binary) (V-Ks)(K7V) = 3.538 ; exemplar GJ 1075 => adopt (V-Ks)(K7V) = 3.35 *** [last updated 12/23/2020] => adopt (U-B)(K7V) = 1.222 => adopt (V-R)(K7V) = 0.802 => adopt (R-I)(K7V) = 0.717 => adopt (V-J)(K7V) = 2.568 => adopt (V-H)(K7V) = 3.186 => adopt (H-Ks)(K7V) = 0.164 => adopt (J-H)(K7V) = 0.619 => adopt (V-Hp)(K7V) = -0.103 => adopt (G-J)(K7V) = 1.983 => adopt (G-Ks)(K7V) = 2.765 (G-V)(K7V) = -0.5655 ; GJ_673 (G-V)(K7V) = -0.577 ; trend for Kervella19 d<25pc for V-Ks=3.35 (G-V)(K7V) = -0.580 ; from color fit for V-Ks=3.33 (G-V)(K7V) = -0.581 ; trend for SIMBAD d<20pc for V-Ks=3.33 (G-V)(K7V) = -0.598 ; exemplar GJ 710 (G-V)(K7V) = -0.601 ; exemplar GJ 455.1 = HD 105065 (G-V)(K7V) = -0.6313 ; GJ_820B (G-V)(K7V) = -0.6945 ; exemplar GJ 1075 => adopt (G-V)(K7V) = -0.58 [updated 11/1/2020] => adopt (G-Ks)(K7V) = 3.33 + -0.58 = 2.75 [updated 7/17/2020] (Bp-Rp)(K7V)= 1.5079 ; GJ 748.2 A ter. stan. (Bp-Rp)(K7V)= 1.5752 ; GJ 764.1 B ter. stan. (Bp-Rp)(K7V)= 1.6221 ; GJ 786 sec. stan. (Bp-Rp)(K7V)= 1.6630 ; GJ 394 ter. stan. (Bp-Rp)(K7V)= 1.6960 ; GJ 710 exemplar (Bp-Rp)(K7V)= 1.6991 ; GJ 265 A ter. stan. (Bp-Rp)(K7V)= 1.6997 ; *_61_Cyg_B pri. stan. (Bp-Rp)(K7V)= 1.7077 ; GJ 455.1 exemplar (Bp-Rp)(K7V)= 1.7154 ; HD_157881 sec. stan. (Bp-Rp)(K7V)= 1.7162 ; GJ_380 ter. stan. (Bp-Rp)(K7V)= 1.7446 ; HD_217357_ K7+Vk (Bp-Rp)(K7V)= 1.7635 ; *_eta_Cas_B_ K7Ve (Bp-Rp)(K7V)= 1.8529 ; HD_79210_ K7V (Bp-Rp)(K7V)= 1.9190 ; HD_32450_ K7V => adopt (Bp-Rp)(K7V) = 1.70 [last updated 7/10/2020] (G-Rp)(K7V)= 0.7922 ; GJ 748.2 A ter. stan. (G-Rp)(K7V)= 0.8134 ; GJ 764.1 B ter. stan. (G-Rp)(K7V)= 0.8277 ; GJ 786 sec. stan. (G-Rp)(K7V)= 0.8510 ; GJ 394 ter. stan. (G-Rp)(K7V)= 0.8605 ; *_61_Cyg_B pri. stan. (G-Rp)(K7V)= 0.8611 ; GJ_710 exemplar (G-Rp)(K7V)= 0.8642 ; GJ_380 ter. stan. (G-Rp)(K7V)= 0.8657 ; GJ 265 A ter. stan. (G-Rp)(K7V)= 0.8674 ; GJ 455.1 exemplar (G-Rp)(K7V)= 0.8697 ; HD_157881_ sec. stan. (G-Rp)(K7V)= 0.8793 ; HD_217357_ K7+Vk (G-Rp)(K7V)= 0.8869 ; *_eta_Cas_B_ exemplar => adopt (G-Rp)(K7V) = 0.86 [last updated 7/10/2020] => adopt (Bp-G)(K7V) = 0.84 [last updated 7/10/2020; Bp-Rp=1.70, G-Rp=0.86] Note: 61 Cyg B appears to have colors close to the median for the standards (K7V) = 2.390 (+-0.035 sem, +-0.249 stdev; HIP d<75pc S/N>8 N=87) (K7V) = 3.005 (+-0.036 sem, +-0.286 stdev; HIP d<75pc S/N>8 N=87) (K7V) = 0.612 (+-0.005 sem, +-0.038 stdev; HIP d<75pc S/N>8 N=87) (K7V) = 0.161 (+-0.003 sem, +-0.030 stdev; HIP d<75pc S/N>8 N=87) (K7V) = 1.504 (+-0.021 sem, +-0.141 stdev; HIP d<75pc S/N>8 N=74) (K7V) =-0.141 (+-0.005 sem, +-0.058 stdev; HIP d<75pc S/N>8 N=74) (K7V) = 4.429 (+-0.057 sem, +-0.401 stdev; HIP d<75pc S/N>8 N=87) (g-r)(K7V) = 1.176 ; Jordi06 (V-R)=>(g-r) for R-I=0.802 (g-r)(K7V) = 1.255 ; Bilir05 (B-V)=>(g-r) for B-V=1.340 (g-r)(K7V) = 1.34 ; Covey07 => adopt (g-r)(K7V) = 1.26 [updated 10/10/2020] Teff(K7V) = 3860 K ; deprecated standard GJ 338B Teff(K7V) = 3887 +- 25 K ; Pecaut13 (GJ 338B) Teff(K7V) = 3961 +- 11 K ; Boyajian12b (N=3) Teff(K7V) = 3964 K ; median Teff for 82 published Teffs for K7V stars Teff(K7V) = 4000 K ; Bessell79 Teff(K7V) = 4000 K ; Bessell91 "old disk" Teff(K7V) = 3990 K ; ter. standard GJ 380 Teff(K7V) = 4040 K ; pri. standard 61 Cyg B ([Fe/H] ~ -0.3) Teff(K7V) = 4057 K ; Morrell19 Teff for stars w/i +-0.1 mag of M_Ks=4.85 Teff(K7V) = 4060 K ; Schmidt-Kaler82 Teff(K7V) = 4065 K ; sec. standard GJ 673 ([Fe/H] ~ -0.2) Teff(K7V) = 4070 K ; ter. stan. GJ 394 Teff(K7V) = 4073 +- 98 K ; Lepine12 Teff(K7V) = 4075 K ; mean photometric Teff for B-V=1.33 Teff(K7V) = 4099 +- 48 K ; vanBelle09 Teff(K7V) = 4114 K ; smooth Teff(SpT) trend Teff(K7V) = 4117 +- 23 K ; Pecaut13 (pri. stan. 61 Cyg B = GJ 820B) Teff(K7V) = 4140 K ; sec. stan. GJ 786 (see below) Teff(K7V) = 4320 K ; ter. stan. GJ 764.1 B (see below) Teff(K7V) = 4320 K ; ter. stan. GJ 265 A (see below) => adopt Teff(K7V) = 4100 K (logT = 3.613) [last updated 9/1/2019] Mv(K7V) = 7.75 mag ; sec. stan. GJ 786 Mv(K7V) = 7.86 mag ; ter. stan. GJ 764.1 B Mv(K7V) = 7.87 mag ; non-stan. HD 204587 Mv(K7V) = 8.01 mag ; Wegner07 Mv(K7V) = 8.04 mag ; exemplar GJ 773 Mv(K7V) = 8.06 mag ; non-stan. GJ 571.1 (unresolved binary) Mv(K7V) = 8.07 mag ; ter. stan. GJ 748.2 A Mv(K7V) = 8.07 mag ; B-V=1.33 => EEM fit to SIMBAD dwarfs d<25pc Mv(K7V) = 8.1 mag ; Schmidt-Kaler82 Mv(K7V) = 8.11 mag ; sec. stan. GJ 673 Mv(K7V) = 8.11 mag ; fit to Yee17 K dwarf L/T for [Fe/H]=0.0 Mv(K7V) = 8.13 mag ; SIMBAD d<20pc trend for K dwarfs for V-Ks=3.35 (M_Ks=8.13) Mv(K7V) = 8.14 mag ; exemplar GJ 455.1 = HD 105065 Mv(K7V) = 8.14 mag ; ter. stan. GJ 394 Mv(K7V) = 8.15 mag ; median Koen10 d<25pc K7V Mv(K7V) = 8.16 mag ; ter. stan. GJ 380 Mv(K7V) = 8.16 mag ; V-Ks=3.35 => EEM fit to MS data Mv(K7V) = 8.17 mag ; V-Ks=3.35 => EEM fit to Reid CNS3 data Mv(K7V) = 8.19 mag ; median K7V d<25pc M_Ks=4.86 (N=58), adopt V-Ks=3.33 Mv(K7V) = 8.20 mag ; non-stan. GJ 710 Mv(K7V) = 8.21 mag ; V-Ks=3.35 =< JohnsonApps09 fit Mv(K7V) = 8.22 mag ; V-K=3.35 => EEM fit to Jao16 data Mv(K7V) = 8.25 mag ; ter. stan. GJ 265 A Mv(K7V) = 8.26 mag ; exemplar GJ 710 Mv(K7V) = 8.33 mag ; pri. stan. 61 Cyg B (see below) Mv(K7V) = 8.37 mag ; exemplar GJ 798 Mv(K7V) = 8.38 mag ; median d<25pc (N=57) Mv(K7V) = 8.39 mag ; exemplar GJ 1267 Mv(K7V) = 8.41 mag ; median SIMBAD K7V d<25pc (N=67) Mv(K7V) = 8.47 mag ; exemplar GJ 56.3 B Mv(K7V) = 8.47 mag ; Henry94 Mv(K7V) = 8.63 mag ; exemplar GJ 34B => adopt Mv(K7V) = 8.16 mag [updated 3/2/2021] (M_Ks=4.81, V-Ks=3.35) => adopt M_G(K7V) = 7.58 mag [updated 3/2/2021] (Mv=8.16, G-V=-0.58) => adopt M_Ks(K7V) = 4.81 mag [updated 3/2/2021] (Mv=8.16, V-Ks=3.35) M_G(K7V) = 6.7547 ; exemplar *_eta_Cas_B_ M_G(K7V) = 6.9265 ; HD_157881_ K7V M_G(K7V) = 7.0477 ; HD_79210_ K7V M_G(K7V) = 7.2521 ; HD_217357_ K7+Vk M_G(K7V) = 7.506 ; SIMBAD d<20pc trend for V-Ks=3.33 M_G(K7V) = 7.54 ; exemplar GJ 455.1 = HD 105065 M_G(K7V) = 7.57 ; Mv=8.15, G-V=-0.58 M_G(K7V) = 7.662 ; exemplar GJ 710 M_G(K7V) = 7.7325 ; pri. stan. *_61_Cyg_B_ K7V_ M_G(K7V) = 7.7507 ; HD_32450_ K7V M_Ks(K7V) = 4.87 mag ; EEM fit to Jao16 for V-Ks=3.35 M_Ks(K7V) = 4.86 mag ; median d<25pc K7V (N=58) M_Ks(K7V) = 4.86 mag ; JohnsonApps09 for V-Ks=3.35 M_Ks(K7V) = 4.82 mag ; EEM fit to Reid CNS3 data for V-Ks=3.35 M_Ks(K7V) = 4.81 mag ; EEM fit to MS data for V-Ks=3.35 M_Ks(K7V) = 4.78 mag ; SIMBAD d<20pc trend for K dwarfs for V-Ks=3.35 M_Ks(K7V) = 4.77 mag ; exemplar GJ 773 = HD 188807 M_Ks(K7V) = 4.64 mag ; SchlaufmanLaughlin10 calib for V-Ks=3.35 BCv(K7V) = -1.218 +- 0.034 ; GJ 338B BCv(K7V) = -1.130 mag ; Masana06(Teff=4100K) BCv(K7V) = -1.001 mag ; Mann15(V-J=2.625) BCv(K7V) = -0.986 mag ; Flower96(Teff=4100K) BCv(K7V) = -0.98 mag ; Bessell91("old disk"; BCv = (V-I)-BC_I) BCv(K7V) = -0.973 +- 0.030 mag ; anchor standard GJ 820B = 61 Cyg B (Pecaut13) BCv(K7V) = -0.969 mag ; sec. stan. GJ 673 (see below) BCv(K7V) = -0.947 mag ; Casagrande18(Teff=4100K,logg=4.5) BCv(K7V) = -0.945 mag ; Mann15(BC_Ks=2.449, for V-J=2.551 and V-Ks=3.33) BCv(K7V) = -0.924 mag ; Bessell98(ATLAS9,logg=4.5,Teff=4100K) BCv(K7V) = -0.921 mag ; pri. stan. 61 Cyg B (see below) BCv(K7V) = -0.902 mag ; Casagrande08(Teff=4100K) BCv(K7V) = -0.884 mag ; Bertone04(ATLAS,Teff=4100K) BCv(K7V) = -0.88 mag ; BC_Ks=2.45, V-Ks=3.33 BCv(K7V) = -0.88 mag ; Schmidt-Kaler82 (BCv=-1.01 + 0.13 offset) => adopt BCv(K7V) = -0.93 mag [updated 7/17/2020, on scale BCv(5772K)=-0.085] BC_Ks(K7V) = 2.453 mag ; Mann15(BC_Ks for V-J=2.568) BC_Ks(K7V) = 2.423 mag ; Morrell19 calib. for G-Ks=2.765 BC_Ks(K7V) = 2.42 mag ; BCv=-0.93, V-Ks=3.35 => adopt BC_Ks(K7V) = 2.42 mag [updated 8/29/2019, adopting BCv=-0.93, V-Ks=3.35] logL(K7V) = -0.75+-0.09 ; ecl. binary V1236_Tau_B (Bayless06) logL(K7V) = -0.76+-0.10 ; ecl. binary V1236_Tau_A (Bayless06) logL(K7V) = -0.867+-0.056 ; ecl. binary IM Vir B [Fe/H]=-0.10+-0.25 (Morales09) logL(K7V) = -0.996 dex ; Mv=8.16, BCv=-0.93 => Mbol = 7.230 logL(K7V) = -1.071 +- 0.036 dex ; pri. stan. 61 Cyg B (Kervalla08) logL(K7V) = -1.0722 ; pri. stan. 61 Cyg B (Newton14) => adopt logL(K7V) = -0.996 dex [updated 3/2/2021] => adopt Mbol(K7V) = 7.230 mag [updated 3/2/2021] Rad(K7V) = 0.817+-0.010 Rsun ; ecl. binary V1236_Tau_B (Bayless06) Rad(K7V) = 0.788+-0.015 Rsun ; ecl. binary V1236_Tau_A (Bayless06) Rad(K7V) = 0.681+-0.013 Rsun ; ecl. binary IM Vir B [Fe/H]=-0.10+-0.25 (Morales09) Rad(K7V) = 0.649+-0.020 Rsun ; sec. stan. GJ 673 = HD 157881 (Yee17) Rad(K7V) = 0.644 Rsun ; Mann15 calib. for M_Ks=4.81 Rad(K7V) = 0.640+-0.005 Rsun ; ter. stan. GJ 380 = HD 88230 (Yee17) Rad(K7V) = 0.6296 Rsun ; logL=-0.996, Teff=4100K Rad(K7V) = 0.6027+-0.0047 Rsun ; Boyajian12b (N=3) Rad(K7V) = 0.601+-0.007 Rsun ; pri. stan. 61 Cyg B (Yee17) Rad(K7V) = 0.595+-0.008 Rsun ; pri. stan. 61 Cyg B (Kervalla08) => adopt Rad(K7V) = 0.630 Msun [updated 3/2/2021] Mass(K7V) = 0.622 Msun ; Mann18 calib (M_Ks=4.81) Mass(K7V) = 0.630 Msun ; Eker15 calibration for logL=-0.996 Mass(K7V) = 0.637 Msun ; Eker18 ML calibration for logL=-0.996 Mass(K7V) = 0.64 Msun ; anchor stan. 61 Cyg B (Wright11) Mass(K7V) = 0.652 Msun ; EEM logL vs. Mass fit for binaries (logL=-0.996) Mass(K7V) = 0.653 Msun ; EEM Mv vs. Mass fit for binaries (Mv=8.16) Mass(K7V) = 0.6644+-0.0048 Msun ; ecl. binary IM Vir B [Fe/H]=-0.10+-0.25 (Morales09) Mass(K7V) = 0.68 Msun ; sec. stan. GJ 673 (Wright11) Mass(K7V) = 0.701 Msun ; M_Ks=4.80 => Delfosse10 calibration Mass(K7V) = 0.770+-0.009 Msun ; ecl. binary V1236_Tau_B (Bayless06) Mass(K7V) = 0.787+-0.012 Msun ; ecl. binary V1236_Tau_A (Bayless06) => adopt Mass(K7V) = 0.64 Msun [updated 3/2/2021] # No standard Houk75, Keenan85, Garrison94, Keenan99 do not list any K7V standards, and Wing79 considers K5-M0 a one subtype jump. # Anchor Standard GJ 820B = HD 201092 = 61 Cyg B = HR 8086 = LHS 63 = HIP 104217 (J2106+3844) K5V: Cannon24,Bidelman85(K5V:),Reid95 K6V: Morgan38,Keenan53 sdK6.9: Houdebine16 *K7V: JM53,1967PDAO...13...47Y,Abt68,MK73,Boeshaar76,KeenanMcNeil76(stan),Keenan80,Abt81,Keenan85,Corbally86(stan,JM53),Keenan88,Keenan89,Kirkpatrick91(pri),Henry94,GrayAtlas,Henry02,Gray03,Reid04 K7.3: Mann15 K8V: Lindblad34 M0V: Adams26,Joy74 M0.5:V: Alonso-Floriano15 M1/3V: Lindblad22 Nearest (3.5 pc) K7V star and longest history of consistent use as standard. plx = 286.1457 0.0590 mas. V=6.03(Johnson66), V=6.05(HIP), V=6.07(Moreno71), V=6.055+-0.024(Mermilloid91), B-V = 1.309+-0.012 (HIP), B-V=1.37(Johnson66), B-V=1.354+-0.024(Mermilliod91), U-B=1.23(Johnson66), U-B=1.231+-0.006(Mermilliod91), V-I = 1.27+-0.01 (HIP), Mv=8.33 (calc with HIP2 plx). Too bright for 2MASS (+-0.3 mag errors). Alonso96 reports near-IR photometry: J=3.470+-0.020, H=2.837+-0.015, K=2.68+-0.017. V-K = 6.055 - 2.68 = 3.375. SIMBAD reports from vanBelle09 K=2.32+-0.05, but this leads to V-K=3.735, way too red for K7V. The V-I color is 0.3 mags bluer than the median color for the 30 Gray01/03/06 K7V stars. Unclear why Hawley97 considered this K7V standard star a K5V? Mass: 0.64 Msun(Wright11). Radius: 0.55 Rsun(Wright11). Teffs: 3808K(Kovtyukh03), 3853K(Boyajian12), 3894K(Koleva12), 3911K(Katz11), 3914K(Ramirez05), 3932K(Boyajian12#2,Yee17), 3945K(Reinhold19), 3954K(Boyajian12#3), 4016K(Soubiran08), 4025K(Newton15#1), 4021K(Mann15), 4044K(Heiter15), 4045K(Jofre14), 4047K(Newton15#2), 4073K(Houdebine16), 4077K(vanBelle09), 4117K(Pecaut13), 4120K(Cesetti13,Molenda-Zakowicz13), 4126K(Mann15), 4349K(Ramirez12), 4353K(Agguilera-Gomez18), 4383k(Biazzo07), 4400K(Luck05,Luck06) => = 4040K. Remarkable spread in Teffs among recent values (>2000), from ~3800K to 4400K (~15% spread). <[Fe/H]> = -0.27(N=9), with best recent metallicity from Jofre14: [Fe/H] = -0.38+-0.03. fbol = 22.25+-0.19(x10pW/m2) => mbol = 5.134+-0.009. BCv = 5.134 - 6.055 = -0.921. Gaia DR2 entry is 80" away from J2000 position due to high proper motion. # Secondary Standard GJ 673 = HD 157881 = LHS 447 = Cin 2322(not in SIMBAD) = Wolf 718 (J1725+0206) K5V: Stephenson86,Hawley97 K6V: Adams35 *K7V: JM53(non-stan),Wilson62,Jaschek64(all),Cowley67,Henry94,Henry02,Gray03,Pecaut13 K7.4: Mann15 M1V: Houk99 3rd nearest K7V (7.7 pc) after 61 Cyg B and HD 88230. Kirkpatrick(DwarfArchives) lists "K7V" and cites Henry94. So Johnson/Morgan/Cowley/Henry/Kirkpatrick/Gray all agree on type. Good enough. It is at J172545.2+020641, so on the equator, and a nice standard (accessible from the south, and hence observed from CTIO in PecautMamajek13 instead of 61 Cyg B). V=7.54(HIP), V=7.543+-0.017(Mermillod91), B-V=1.359+-0.011(HIP), B-V=1.360+-0.010(Mermilliod91), U-B=1.260+-0.013(Mermilliod91), V-I=1.62+-0.01(HIP). 2MASS photometry: only J is good (J=4.934+-0.024), but H is flagged qual='E' (4.341+-0.044), and Ks = 4.370+-0.274 mag. The V-J color (2.606) corresponds to V-Ks color V-Ks=3.396 on dwarf color locus. Mass: 0.68 Msun(Wright11). Teffs: 3911K(Prugniel07#2), 3941K(Ramirez05), 3947K(Prugniel07#1), 3959K(Wu11), 3962K(Prugniel11), 4011K(diBenedetto98),4030K(vanBelle09), 4035K(Kovtyukh03), 4065K(Alonso96,Katz11), 4069K(Prugniel07#3), 4073K(LeBorgne03), 4100K(Morales08), 4104K(Schiavon07), 4124K(Mann15), 4170K(Mann15), 4180K(Zorbil98), 4220+-73K(Gaidos14) => = 4065K. [Fe/H]=0.11+-0.08(Gaidos14), R=0.64+-0.04Rsun(Gaidos14), Mass=0.68+-0.07Msun(Gaidos14). fbol = 5.927+-0.045(e-11 W/m2; Mann15) => mbol = 6.571+-0.008. BCv = 6.571 - 7.54 = -0.969. plx = 129.86+-0.73mas(vanLeeuwen07), plx = 129.6231 0.0286 mas (GaiaDR2). G = 6.9265 0.0004 (Gaia DR2), (Bp-Rp) = 1.7154, (Bp-G) = 0.8457, (G-Rp) = 0.8697. GaiaDR2 plx and Merilliod91 V => Mv=8.106+-0.017. GJ 786 = HD 193202 = BD+76 785 K5: 1956PMcCO..13a....B *K7V: Bidelman85(K7),Kirkpatrick91(sec),Gray03,Alonso-Floriano15 M0V: Adams26,Lee47(M0) M0.5V: Joy74 V=8.88(HIP), V=8.884+-0.005(Mermilliod91), B-V=1.320+-0.001(HIP), B-V=1.319+-0.015(Mermilliod91), U-B=1.28(Mermilliod91), V-I=1.53+-0.00(HIP), plx=59.08+-0.66mas(vanLeeuwen07), plx = 59.4428 0.0260 mas (GaiaDR2). Mv = 7.754+-0.005(GaiaDR2,Mermilliod91). J = 6.409+-0.023(2MASS), H = 5.819+-0.017(2MASS), Ks=5.667+-0.016(2MASS). V-Ks = 8.884 - 5.667 = 3.217. plx= 59.08+-0.66mas(HIP2), Mv = 7.74+-0.03. Teffs: 4000K(GaiaDR2), 4122K(GaiaDR2/APSIS), 4155K(Macdonald17), 4170K(Morales08) => = 4140K. G = 8.3133+-0.0004(Gaia DR2), Bp-Rp = 1.6221, Bp-G = 0.7944, G-Rp = 0.8277 (GaiaDR2). # Tertiary Standard GJ 380 = HD 88230 = LHS 280 = G 196-9 = HIP 49908 = Groombridge 1618 K5V: Cannon(K5),Hawley97 K6Ve Fe-1: Keenan89 *K7V: Popper56,Wilson62,Boeshaar76(stan),Sato90,Kirkpatrick91(pri,Kirkpatrick12),Montes01,Henry02,Dieterich12 K7.5: Lepine13 K7.6: Mann15 K8V: Gray03 K9Ve: Cowley67(Jaschek78) M0V: Adams26,Joy74 M0.5: Terrien15(Newton near-IR) M1: Terrien15(PMSU near-IR) M3: Gaidos14 2nd nearest K7V star (4.9 pc). I'll adopt K7V based on Boeshaar76, Kirkpatrick91, Henry02, but the K8V from Gray03 and K6Ve Fe-1 from Keenan89 cause me to weaken this object as a standard. Presumably it looks sufficiently different from 61 Cyg B to warrant a classification different from K7V. Gaidos14 type seems extremely discrepent. Mann15 type of "K7.6" where 1 step between K7 and M0, hence K7.6 ~> K9. V=6.60(HIP), B-V=1.326+-0.008(HIP), V-I=1.29+-0.01. 2MASS photometry saturated DDD. Teffs: 3764K(Alonso96), 3772K(Katz11), 3855K(Terrien15#2), 3876K(Soubiran08), 3893K(Terrien15#1), 3947K(Wu11), 3950K(Ramirez05), 3954K(Terrien15#3), 3960K(Prugniel11), 3970K(Woolf05), 3980K(Lepine13), 4000K(Onehag09), 4060+-87K(Boyajian12#2), 4081K(Eiroa13, Boyajian12#1), 4085+-14K(Boyajian12#3), 4085K(Frasca15), 4100K(Morales08), 4128K(Schiavon07), 4131+-60K(Mann15), 4162+-33K(Mann15#2), 4176+-19K(Newton15), 4203+-73K(Boyajian12#4) => = 3990K. plx = 205.21+-0.54mas(vanLeeuwen07), plx=205.3917+-0.0342mas(GaiaDR2). => Mv = 8.16+-0.01. [Fe/H] = 0.28(Prugniel07#1), 0.28(Oinas77), -0.03+-0.18(Woolf05), -0.05(Prugniel07#2). Boyajian12 reports tetLD=1.225+-0.009mas. Boyajian12+GaiaDR2 => Rad = 0.641Rsun. GJ 764.1 B = HD 184860 B = CCDM 19368-1027 B = NLTT 47996 B *K7V: Bidelman85(K7),Kirkpatrick91(stan) K5: Reid95 5.6" binary with K3V. V=10.093+-0.00(UCAC4), V=9.98(Tycho), J=7.503+-0.037(2MASS), H=6.890+-0.067(2MASS), Ks=6.796+-0.042(2MASS). Combined Vmag(AB) = 8.400(Mermillod91), adopting delta(Hp)=1.43+-0.02(HIP), assume delta(Hp)=delta(V), then V(B) = 10.088. Adopt V=10.09(from this calculation and UCAC4). V-Ks = 10.09-6.796 = 3.294. Teff: 4320K(Morales08). logg=4.57(Takeda07). Mass=0.778Msun(Takeda07). Not a particularly well-studied star. plx = 35.85+-1.42mas(vanLeeuwen07) => Mv = 7.86. Bp-Rp=1.5752, Bp-G=0.7618, G-Rp=0.8134. GJ 265 A = HIP 34222 = K5V: Bidelman85(K5),Stephenson86,Reid95 *K7V: Kirkpatrick91(stan),Casares93,Lepine13(K7) M0V: Joy47,Vystotsky43 V=10.14(HIP), V=10.22(Mermilliod91), B-V=1.320(Mermilliod91), U-B=1.200(Mermilliod91), J=7.596+-0.024(2MASS), H=6.959+-0.023(2MASS), Ks=6.781+-0.021(2MASS), V-Ks=3.359. Companion 12.8" away? Teffs: 4320K(Morales08). plx = 41.89+-2.19mas(vanLeeuwen07) => Mv = 8.25. Bp-Rp=1.6991, Bp-G=0.8333, G-Rp=0.8657. GJ 394 = HD 237903 = 36 UMa B = BD+56_1458 K5: Cannon,Bidelman85(Kuiper) K6Ve: Popper43 *K7V: JM53(stan),Lepine13(K7.0),Newton14(stan),Alonso-Floriano15 K7.1: Mann13 M0V: Vyssotsky42,Gaidos14(M0) M1: Lee47 Not listed as a K7V standard by Kirkpatrick or Henry, but appears in multiple recent surveys as K7V. It is listed along with 61 Cyg B as a K7V standard by JM53. V=8.691+-0.009(Mermilliod91), (B-V)=1.352+-0.016(Mermilliod91), J=6.119+-0.020(2MASS), H=5.449+-0.034(2MASS), Ks=5.361+-0.016(2MASS). V-Ks = 8.691 - 5.361 = 3.330. plx = 78.4+-6.7mas(Finch16), plx = 74.9+-5.6mas(GCTP), plx = 77.41+-0.27mas(GaiaDR1) => Mv = 8.14. [Fe/H]=-0.07+-0.03(Mann15). Teff: 4050K(Lepine13), 4069K(Cenarro01), 4076K(Prugniel11), 4132K(Gaidos14), => = 4070K. Bp-Rp=1.6630, Bp-G=0.8120, G-Rp=0.8510. GJ 748.2 A = G 22-21 = LHS 3447 = HIP 94590 A K5: Reid95 *K7V: Lee84(K7),Kirkpatrick91(sec.stan) Northern of 8.4" binary. WDS lists pair as having V(A)=10.32, V(B)=11.25. V(AB)=9.85(HIP). V(A)=10.208(Mermilliod91), B-V(A)=1.206(Mermilliod91). 2MASS photometry clearly separated. J(A)=7.921+-0.024(2MASS), H(A)=7.297+-0.036(2MASS), Ks(A)=7.182+-0.020(2MASS). V-Ks = 10.208 - 7.182 = 3.026. Kirkpatrick91 lists both as standards with A as K7V and B as M0V. Not a well-studied star, and does not appear in much literature after being listed as standard in Kirkpatrick91. plx = 28.12+-3.37mas(vanLeeuwen07), plx = 37.43+-0.49mas(GaiaDR1) => Mv = 8.07. Bp-Rp=1.5079, Bp-G=0.7157, G-Rp=0.7922. # Deprecated Standards GJ 338B = HD 79211 = LHS 261 *K7V: Bidelman85,Kirkpatrick91(sec),Hawley97,Henry02,Reid04 M0V: Adams26,Morgan38,Roman55,Stephenson86,Alonso-Floriano15 M0.5V: Joy74 M1V: Newton15(near-IR) This star appears to be significantly cooler than the primary and secondary K7V standards. "B" is 17" away from primary "A". Kirkpatrick91 notes that "B" is 1 subtype earlier than "A"! Note that Mermilliod91's photometry shows HD 79211 (GJ 338B) to be slightly dimmer (.05mag), slightly redder 0.009mag in B-V, and slightly redder in U-B. Interestingly, the following studies found the two components to have identical spectral types: Adams26(M0V+M0V), Morgan38(M0V+M0V), Roman55(M0V+M0V), Joy74(M0.5V+M0.5V). Stephenson86(M0V+M0V), Bidelman85(K7V+K7V). I'm wondering if the Kirkpatrick91 classification spectrum was a single spurious datum? Teffs: 3695K(Jenkins09), 3769K(Milone11), 3849K(Prugniel11), 3869K(Rojas-Ayala12), 3892K(Newton15#1), 3926K(Newton15#2) => = 3860K. V= 7.697+-0.030(Mermilliod91), B-V=1.419+-0.018(Mermilliod91), U-B=1.238+-0.041(Mermilliod91). Metallicities: [Fe/H]=-0.46(Katz11), -0.40(MoroMartin15), -0.38(Frasca09), -0.35(Jenkins09), [Fe/H]=-0.15+-0.17(RojasAyala12), -0.15+-0.10(Yee17), -0.06+-0.08(Gaidos14), -0.07+-0.09(Gaspar16), +0.34(Luck17), GJ 185AB = HD 32450 AB *K7VJ: Henry94,02("joint"),Hawley97("Gl 185A"),GrayNstars(stan) M0V: Houk88 Reid04 calls GJ 185B M2.0. GJ 638 = HD 151288 = Cin 18 2238 K5: Cannon,Bidelman85,Hawley97 K6V: Morgan38 *K7V: JM53(non-standard),Wilson62,Jaschek78,Stephenson86,Gray03,Kirkpatrick(unpub.,DwarfArchive) K7.5Ve: Keenan83,Keenan85,Keenan88,Keenan89(stan) M0V: Adams26 M0.5V: Joy74 M1: Lee47 Keenan called it K7.5V, so one might suppose this is halfway between K7V and M0V since he didn't use K8 or K9 subtypes. See K7.5V.txt file. GJ 430 = HIP 56199 = StKM 1- 952 = BD+63 965 K5: Stephenson86,Hawley97 *K7V: Kirkpatrick91(sec.stan.),Alonso-Floriano15 K7.5: Lepine13 M0V: Vyssotsky46,Lee47(M0),Joy74 Teff=4000K(Lepine13), 4290K(Morales08) => =4145K. No PASTEL entry. plx=43.49+-0.24(GaiaDR1). # Examplars GJ 798 = HD 196877 = LHS 496 = HIP 102186 = NLTT 49687 = UGP 501 = Smethells 63 = LTT 8183 K5V: Houk75,Reid95 *K7V: Warner63,Evans64,Upgren72,Smethells74,Walker83,Gray06 V=8.829+-0.003(Mermilliod91), B-V=1.318+-0.006(Mermilliod91), U-B=1.13(Mermilliod91), J=6.274+-0.021(2MASS), H=5.665+-0.031(2MASS), Ks=5.474+-0.024(2MASS), V-Ks = 8.829 - 5.474 = 3.355. plx = 80.93+-0.26mas(GaiaDR1). Mv = 8.37+-0.01. GJ 56.3 B = HD 7895 B *K7V: Stephenson86,Gaidos14(K7),Alonso-Floriano15 M0: Bidelman85 (B-V)=1.401+-0.044(Mermilliod91), V=10.675+-0.033(Mermilliod91), U-B=1.222+-0.076(Mermilliod91), J=8.012+-0.021(2MASS), H = 7.369+-0.029(2MASS), Ks=7.190+-0.020(2MASS). V-Ks = 10.676 - 7.190 = 3.485. plx = 37.75+-0.95mas(HIP2), plx = 36.18+-0.30mas(GaiaDR1), Mv = 8.467+-0.038. GJ 1267 = HD 211970 = HIP 110443 K5: Hawley97 *K7V: Upgren72,Smethells74,Gray06(K7V(k)) M0V: Houk75 V=8.98(HIP), V=8.992(Koen10), V=9.06(Mermilliod91), B-V=1.329+-0.017(HIP), B-V=1.35(Mermilliod91), B-V=1.346(Koen10), U-B=1.17(Mermilliod91), U-B=1.170(Koen10), V-I=1.54+-0.03(HIP), V-Ic=1.557(Koen10), J=6.462+-0.029(2MASS), H=5.842+-0.040(2MASS), Ks=5.663+-0.021(2MASS), V-Ks = 8.992 - 5.663 = 3.329. plx = 73.90+-1.21mas(vanLeeuwen07), plx = 75.88+-0.25(GaiaDR1). Mv = 8.39+-0.01. GJ 34B = eta Cas B = HD 4614B = LHS 122 = HIP 3821 B = BD+57 150 B K3ep: Slettebak63 K4Ve: Lutz77 K5: Bidelman85 *K7V: Jaschek78(Edwards76),Henry94,Henry02,Alonso-Floriano15 M0-V: Keenan89(non-stan) M0V: Adams26,Joy74 Note that Joy74's M0V stars seem to correspond to ~K7V on Kirkpatrick91 system, so the Joy74 value is really consistent with the others. B-V=1.393+-0.005(Mermilliod91), V=7.507+-0.005(Mermilliod91), U-B=1.030(Mermilliod91), all 2MASS photometry low quality (too bright). I can't find any published Teff estimates. plx = 167.98+-0.48mas(GaiaDR1). Mv = 8.63+-0.01. GJ 455.1 = HD 105065 = HIP 59000 = 2MASS J12055065-1852304 K7-Vke: Gray06 *K7V: Upgren72, Stephenson86,Reid95 M0V: Vyssotsky56 V=9.99(HIP), B-V=1.336+-0.014(HIP), V-I=1.57+-0.02(HIP), Ks=6.615+-0.018(2MASS), V-Ks = 9.99 - 6.615 = 3.375. GaiaDR2: plx=42.7177+-0.0628mas, G=9.3892 0.0008, E(BR/RP)=1.285, Bp-Rp=1.7077, Bp-G=0.8403, G-Rp=0.8674. Mv=8.143+-0.010, M_G=7.542+-0.003, M_Ks=4.768+-0.018, G-V = 9.3892 - 9.99 = -0.601. GaiaDR2 shows big RV error (-29.16+-13.60 km/s), and Jack19 lists it in a catalog of SB candidates. GJ 710 = HD 168442 = 2MASS J18195084-0156190 K5V: Hawley97(K5),Houk99 *K7V: Upgren72,Bidelman85(K7),Gray06(K7V k) M0V: Vysttosky43,Lee47(M0) M1V: Woolley70(M1),Joy74 Wide range of published types during 20th century between K5 and M1, but Gray classifies K7V. Famous star which will pass within ~16,000 AU of solar system in 1.354 Myr (Bailer-Jones17). V=9.659+-0.012, B-V=1.367+-0.010, U-B=1.216+-0.012(Mermilliod91), Ks=6.280+-0.023(2MASS), V-Ks= 9.659-6.280= 3.379. plx = 51.12+-1.63mas(vanLeeuwen07) => Mv = 8.20. In 1.354 Myr at distance 0.08pc (dist modulus = -10.485!), this star will appear at apparent magnitude V = -2.29. GaiaDR2: plx=52.5185+-0.0478mas, G=9.0608 0.0005, E(BR/RP)=1.281, Bp=Rp=1.6960, Bp-G=0.8349, G-Rp=0.8611. Mv=8.261+-0.012, M_G=7.662+-0.002, M_Ks=4.882+-0.023, G-V=-0.598. GJ 773 = HD 188807 = StKM 2-1425 = UGP 483 *K7V: Upgren72,Bidelman85(K7),Stephenson86,Gray06 K8/M0V: Vyssotsky52 M1.5V: Joy74 WDS companion 62.8" away. V=9.292+-0.010(Mermilliod91), B-V=1.321+-0.014(Mermilliod91), U-B=1.205+-0.079(Mermilliod91), J=6.187+-0.018(2MASS), H=6.197+-0.024(2MASS), Ks=6.015+-0.016(2MASS), V-Ks = 3.277. plx = 56.26+-0.31mas(GaiaDR1). Mv = 8.04+-0.02, M_Ks=4.77. GJ 1075 = HIP 23708 = 2MASS J05054736-5733138 K5V: Reid95 *K7V: Upgren72, Gray06(K7Vk), Gaidos14(K7) V=8.98(HIP), B-V=1.386+-0.012(HIP), V-I=1.64+-0.02(HIP), J=6.272+-0.023(2MASS), H=5.633+-0.044(2MASS), Ks=5.442+-0.018(2MASS) => (V-Ks) = 8.98 - 5.442 = 3.538. plx=85.5301+-0.015mas(GaiaEDR3). Mv=8.64, M_Ks=5.10. G=8.2855+-0.0006(GaiaDR2). G-V = 8.2855 - 8.98 = -0.6945. # Other Stars GJ 215 = LHS 1782 = HIP 27188 = BD+62 780 = G 249-18 = TYC 4098-1836-1 = StKM 2-421 = MCC 466 = LTT 11713 K5V: Joy47 *K7V: Bidelman85(K7),Stephenson86,Reid95(K7) M0V: Lee47(M0),Vyssotsky56(M0Vp),Gaidos14(M0) GJ 884 = HD 217357 K5V: Reid85,Stephenson86 K7V: Upgren72,Bidelman85(K7) *K7+Vk: Gray06 M0V: Vyssotsky52 M0.5V: Joy74 M1V: Adams26 M1/3V: Cannon24 GJ 571.1 = HD 132683 K7V: Upgren72,Bidelman85(K7),Stephenson86,Reid95,Gaidos14(K7) *K8Vk: Gray06 M0V: Adams26 M0.5V: Joy74 M2V: Vyssotsky43 Appears as K8V in Gray, but K7V in 5 independent other sources (2 modern types on Kirkpatrick system). Maybe redder and brighter due to unresolved binarity. V=9.49(HIP), B-V=1.372+-0.008(HIP), J=6.82+-0.024(2MASS), H=6.148+-0.034(2MASS), Ks=5.988+-0.017(2MASS), V-Ks = 3.502. plx = 51.70+-1.97mas(vanLeeuwen07) => Mv = 8.06. HD 204587 = StKM 2-1528 = BD-13 5945 K5V: Stephenson86,Hawley97 *K7V: Upgren72,Bidelman85(K7),Gray06(K7V(k)) K8:: Mukai90 K8/M0V: Vyssotsky46 M0V: Adams35,Roman55,Joy74 V=9.110+-0.015(Mermilliod91), B-V=1.257+-0.020(Mermilliod91), U-B=1.245+-0.005(Mermilliod91), J=6.656+-0.020(2MASS), H=5.990+-0.046(2MASS), Ks=5.881+-0.026(2MASS), V-Ks = 9.110 - 5.881 = 3.229. plx = 56.59+-0.33mas(GaiaDR1). Mv = 7.87+-0.02. Wo 9757 = HIP 107758 = BD-12 6102 K5: Bidelman85 *K7-V(k): Gray06 K7V: Stephenson86,Gaidos14 HD 15285 = StKM 2-210 *K7V: Cowley69,Bidelman85,Reid95(K7),Gaidos14 M1V: Lee47(M1),Gray03 M1.5V: Joy74 M2V: Vyssotsky52 Has 4 K7V classifications in Skiff compendium, but it is a tight binary - 0.4-0.1" (WDS) - and some other classifications as early M. (B-V)=1.405+-0.022(Mermilliod91). GJ 4A = HD 38A = LHS 1016 = CABS 2 = BD+45 4408A = 2MASS J00054091+4548435 K6Ve: Joy47,Tamazian06 *K7: Bidelman85,Reid95 M0V: Adams26,1987ATsir1517....1A 6" binary with slightly cooler companion (M0.5V standard GJ 4B). GK Tau = Haro 6-22 6 K7 classifications in Skiff compendium, but is a pre-MS star. D=140pc, so colors will be affected by interstellar reddening. GJ 414A = HD 97101 = BD+31 2240 = Lalande 21368 = HIP 54646 = LHS 2367 = WDS J11111+3027A = 2MASS J11110509+3026459 K5V: Boss37(K5),Stephenson86 K6.1: Houdebine16(dK6.1) *K7V: Bidelman85(K7),Gray03 K8V: Eiroa13 K9V(e): Cowley67,Neves13 M0Vp: Lee47(M0),Vyssotsky56(M0Vp) M0.7+-0.3: Sebsastien21(photometric) M1V: Adams26,Joy74 Dedrick21(https://arxiv.org/abs/2009.06503v1) reports the discovery of two exoplanets, one near hab zone. 34" binary with ~M2 "B". One of 2 K9Vs in Cowley67. plx=84.1766+-0.0258mas(GaiaEDR3). V=8.303+-0.001(Hauck97), V=8.338+-0.029(Mermilliod91), B-V=1.351+-0.008(Mermilliod91), U-B=1.278+-0.010(Mermilliod91). J=5.764+-0.020(2MASS), H=5.130+-0.020(2MASS), Ks=4.979+-0.018(2MASS). V-Ks = 8.303 - 4.979 = 3.324 (not far from to K7V median). Mv = 7.93, M_Ks = 4.61. [Fe/H] = +0.24+-0.10(Dedrick21). Teffs: 4030+-100K(Houdebine16#1), 4060+-130K(Stassun19), 4085+-82K(Leger15), 4085K(Hinkel17), 4100K(Cifuentes20), 4120+-109K(Dedrick21), 4185+-155K(Houdebine16#2), 4189K(Luck17), 4286+-106K(Sebastien21), 4340K(Houdebine16#3), 4468K(Moro-Martin15), 4509K(Xiang15) => adopt Teff=4120+-109K from Dedrick21. Lum = 0.11Lsun(XHIP), Lum = 0.119+-0.013Lsun(Dedrick21) => logL=-0.924+-0.048, Lum = 0.12530+-0.00158Lsun(Cifuentes20) => logL=-0.90205, Lum = 0.13711+-0.01013Lsun(Stassun19) => logL=-0.863+-0.032, Lum = 0.146Lsun(Moro-Martin15), Lum = 0.166Lsun(Eiroa13), logL = -0.95(Luck17). EEM calc of luminosity: V=8.303, BCv=-0.97, plx=84.1766mas => logL = -0.904. Masses: 0.61Msun(Richey-Yowell19), 0.636+-0.050Msun(Jenkins09), 0.640+-0.085Msun(Stassun19), 0.650+-0.08Msun(Dedrick21), 0.65+-0.02Msun(Sebastien21), 0.653Msun(EEM calc using Mann18 calib from M_Ks, [Fe/H]=+0.24), 0.669+-0.039Msun(EEM calc using fit to Torres10 binaries), 0.682Msun(Anders19), 0.695+-0.013Msun(Kervella19), 0.70+-0.01Msun(Luck17), 0.70+-0.01(Kervella22), 0.7016+-0.0177Msun(Cifuentes20), 0.7163+-0.0234Msun(Cifuentes20), 0.738Msun(Newton17), 0.74+-0.03Msun(Neves13). Prot=39.7d(Dedrick21). HD 21531 = StKM 2-291 = UGP 56 = BD-20 643 K5V: Houk88 K6Vk: Gray06 *K7V: Cowley67,Upgren72,Stephenson86 M0V: Adams26,Vyssotsky46 M0.5V: Joy74 # Notes RECONS list shows GJ 820B (61 Cyg B; J2106+3844) as the nearest K7.0V star, followed by GJ 380 (J1011+4927). The colors of 61 Cyg B do not match well the median colors of the K7V stars in Hipparcos, suggesting systematic differences in classifications of these objects by different authors (probably mostly Houk & collaborators, as they do not list any spectral standards between K5V and M2V). The K7V star with median B-I color is HIP 102186. The brightest K7V stars are HIP 104217 (V=6.05) and HIP 85295 (V=7.54). Among the nearest 100 systems, I find 5 K7V stars (*=standard) GJ_820_B_* K7V 1989ApJS...71..245K B-V=1.309+-0.012 V-I=1.27+-0.01 GJ_825_ K7.0V 1995AJ....110.1838R GJ_380_ K7V 1991ApJS...77..417K GJ_34_B_ K7V 2002AJ....123.2002H GJ_338_A_ K7V 1991ApJS...77..417K