A3V Garrison94 lists alf PsA as the A3V anchor standard, and MK73 lists alf PsA as the A3V dagger standard. alf PsA (= Fomalhaut) is clearly the best A3V standard. MK43 standard: alf PsA - A3V bet Leo - A3V 38 Lyn - A3V del UMa - A3V zet Vir - A3V JM53 standards: alf PsA - A3V bet Leo - A3V lam Gem - A3V Abt68 standard: Coma T183 - A3V Cowley69 standards: lam Gem - A3V bet Leo - A3V 38 Lyn - A3V del UMa - A3V zet Vir - A3V Houk75 standard: alf PsA - A3V bet Leo - A3V MK78 standard: BD+48_944 (= HL 970) - A3V Garrison79 standard: alf PsA - A3V Keenan85 standard: BD+48_944 - A3V GrayGarrison89 standards: alf PsA - A3Va bet Cir - A3Vb bet Leo - A3Va HD 23643 - A3Van Garrison94 anchor: alf PsA - A3V GrayAtlas standard: bet Leo - A3V GrayNstars standard: bet Leo - A3V Skiff08 flagged two stars as A3V standards: HD 216956 (MK73) & BD+48_944 (MK78) For A3V Hipparcos stars within 75pc, with parallax S/N > 8, and within 1 mag of the MS (N=21): (A3V) = 0.283 (+-0.033 sem, +-0.118 stdev; N=21) (A3V) = 0.313 (+-0.041 sem, +-0.159 stdev; N=21) (A3V) = 0.375 (+-0.046 sem, +-0.166 stdev; N=21) (A3V) = 0.032 (+-0.012 sem, +-0.051 stdev; N=21) (A3V) = 0.054 (+-0.011 sem, +-0.034 stdev; N=21) (A3V) = 0.159 (+-0.015 sem, +-0.065 stdev; N=21) (A3V) =-0.015 (+-0.002 sem, +-0.009 stdev; N=21) (A3V) = 0.519 (+-0.068 sem, +-0.228 stdev; N=21) (B-V)(A3V) = 0.049 ; HD 27962 (Morgan65's only A3V Hyad) (B-V)(A3V) = 0.057 ; exemplar HD 23848 = HR 1177 (B-V)(A3V) = 0.07 ; exemplar HD 151431 = 19 Oph (B-V)(A3V) = 0.08 ; Fitzgerald70 (B-V)(A3V) = 0.08 ; Schmidt-Kaler82 (B-V)(A3V) = 0.086 ; tert. stan. HD 23643 (Pleiad) (A3V) = 0.087 (+-0.002 sem, +-0.004 stdev); Gray01/03/06 (N=5) (B-V)(A3V) = 0.088 ; sec. stan. bet Cir (B-V)(A3V) = 0.090 ; pri. stan. bet Leo (B-V)(A3V) = 0.09 ; JohnsonMorgan53,Johnson63,Garrison67,Morgan71, KenyonHartmann95 (B-V)(A3V) = 0.094 ; anchor stan. alf PsA (B-V)(A3V) = 0.097 ; smoothed trend SpT vs (B-V)o B9.5V-F3V 11/2021 (B-V)(A3V) = 0.098 ; exemplar HD 52859AB (B-V)(A3V) = 0.105 ; exemplar HD 51693 = HR 2606 (B-V)(A3V) = 0.108 ; ter. stan. BD+48_944 = Cl Melotte 20 970 (alpha Per cluster) (B-V)(A3V) = 0.121 ; exemplar HD 31283 = HR 1569 (B-V)(A3V) = 0.125 ; d<60pc SIMBAD N=12 (A3V) = 0.137 (+-0.015 sem, +-0.061 stdev); HIP d<75pc S/N>8 (N=21) (B-V)(A3V) = 0.142 ; BakisEker22 => adopt (B-V)(A3V) = 0.10 *** [updated 9/20/2019] => adopt (U-B)(A3V) = 0.085 => adopt (V-I)(A3V) = 0.119 => adopt (V-R)(A3V) = 0.056 => adopt (R-I)(A3V) = 0.064 => adopt (V-J)(A3V) = 0.215 => adopt (V-H)(A3V) = 0.218 => adopt (V-Ks)(A3V) = 0.253 => adopt (H-Ks)(A3V) = 0.035 => adopt (J-H)(A3V) = 0.003 [EEM comment: Somewhat surprisingly, the main standard Fomalhaut appears to be significantly redder than most A3V stars. (Bp-Rp)(A3V) = 0.110 ; color trend for B-V=0.10 (Bp-Rp)(A3V) = 0.143 ; Evans18 trend for V-I=0.119 => adopt (Bp-Rp)(A3V)= 0.110 [updated 11/22/2020] (Bp-G)(A3V) = 0.014 ; color trend for B-V=0.10 => adopt (Bp-G)(A3V) = 0.014 [updated 11/22/2020] (G-Rp)(A3V) = 0.092 ; color trend for B-V=0.10 => adopt (G-Rp)(A3V) = 0.092 [updated 11/22/2020] (Ks-W1)(A3V) = 0.045 ; EEM trend for d<30pc for B-V=0.10 => adopt (Ks-W1)(A3V) = 0.045 [updated 12/29/2019] (G-V)(A3V) = -0.061 ; * 100 Her B A3V (G-V)(A3V) = -0.047 ; HD 88480 * A3V (G-V)(A3V) = -0.027 ; HD 50445 PM* A3V (G-V)(A3V) = -0.025 ; HD 19545 PM* A3V (G-V)(A3V) = -0.023 ; * b01 Hya * A3V (G-V)(A3V) = -0.012 ; HD 145689 PM* A3V (G-V)(A3V) = -0.012 ; HD 20888 PM* A3V (G-V)(A3V) = -0.011 ; polynomial fit for f(B-V) (G-V)(A3V) = -0.010 ; * del Aqr PM* A3Vp (G-V)(A3V) = -0.009 ; * 60 Her PM* A3V (G-V)(A3V) = -0.005 ; interp A2V(0.00) and A4V(-0.01) (G-V)(A3V) = -0.006 ; * pi. Ser * A3V (G-V)(A3V) = 0.005 ; fit for A dwarfs from Kervella19 corrected for E(B-V), eval for (V-Ks)=0.253 (G-V)(A3V) = 0.006 ; * eps01 Lyr A A3V (G-V)(A3V) = 0.008 ; * l Per PM* A3V => adopt (G-V)(A3V) = -0.005 [updated 4/8/2022] (U-B)(A3V) = 0.08 ; Fitzgerald70 (U-B)(A3V) = 0.084 ; HIP d<75pc S/N>8 A3V N=45 (Mermilliod91 photometry) (U-B)(A3V) = 0.07 ; JohnsonMorgan53 (A3V) = 0.083 (+-0.013 sem, +-0.023 stdev); Gray01/03/06 (N=5) (A3V) = 0.152 (+-0.017 sem, +-0.065 stdev); HIP d<75pc S/N>8 (N=21) (g-r)(A3V) = -0.016 ; Jordi06 (V-R)=>(g-r) for V-R=0.056 (g-r)(A3V) = -0.139 ; Bilir05 (B-V)=>(g-r) for B-V=0.100 (g-r)(A3V) = -0.16 ; Covey07 => adopt (g-r)(A3V) = -0.14 [updated 10/10/2020] Teff(A3V) = 8720 K ; Schmidt-Kaler82 Teff(A3V) = 8656 K ; sec. stan. bet Cir (median Teff) Teff(A3V) = 8630 K ; Zorec12 median Teff(A3V) = 8625 K ; Theodossiou90 Teff(A3V) = 8610 K ; anchor stan. Fomalhaut (median Teff) Teff(A3V) = 8604 K ; pri. stan. bet Leo (median Teff) Teff(A3V) = 8560 K ; GrayCorbally94 Teff(A3V) = 8546 K ; mean photometric Teff Teff(A3V) = 8520 K ; GrayCorbally09 Teff(A3V) = 8503 K ; EEM N=171 Teff Teff(A3V) = 8400 K ; median for 5 A3V from Gray17 Teff(A3V) = 8261 K ; ter. stan. BD+48_944 = Cl Melotte 20 970 (alpha Per cluster) Teff(A3V) = 8258 K ; ter. stan. HD 23643 = Cl Melotte 22 1425 (Pleiad) Teff(A3V) = 8214 K ; Boyajian12 => adopt Teff(A3V) = 8600 K (logT = 3.934) [updated 9/16/2019] BCv(A3V) = -0.087 mag ; Flower96(Teff=8600K, set BCv(5772K)=-0.085) BCv(A3V) = -0.04 mag ; Schmidt-Kaler(BCv=-0.17 + 0.13 offset) BCv(A3V) = -0.042 mag ; Code76(Teff=8600K, set BCv(5772K)=-0.085)) BCv(A3V) = -0.041 mag ; Balona94(Teff=8600K, set BCv(5772K)=-0.085)) BCv(A3V) = -0.030 mag ; Bessell98(ATLAS9,logg=4.5,Teff=8600K, set BCv(5772K)=-0.085)) BCv(A3V) = -0.008 mag ; Bertone04(Teff=8600K,ATLAS, set BCv(5772K)=-0.085)) => adopt BCv(A3V) = -0.04 [updated 9/16/2019; set so BCv(5772K)=-0.085) Mv(A3V) = -0.85 mag ; exemplar HD 151431 = 19 Oph Mv(A3V) = 0.56 mag ; exemplar HD 23848 = HR 1177 Mv(A3V) = 0.94 mag ; exemplar HD 31283 = HR 1569 Mv(A3V) = 1.15 mag ; Wegner07 Mv(A3V) = 1.48 mag ; d<60pc Mv(B-V=0.09) Mv(A3V) = 1.5 mag ; Schmidt-Kaler82 Mv(A3V) = 1.51 mag ; linear B-V vs. Mv fit to d<50pc Gray01/03/06 dwarfs for B-V=0.10 Mv(A3V) = 1.545 mag ; Wright05(B-V=0.09) Mv(A3V) = 1.6 mag ; EEM logT vs Rad trend for A3V Mv(A3V) = 1.60 mag ; median Mv for A3V calc using Kervella19 HIP & Gaia DR2 (d<100pc) Mv(A3V) = 1.63 mag ; interp BAF dwarf seq for B-V=0.10 Mv(A3V) = 1.64 mag ; sec. stan. HD 135379 = Bet Cir Mv(A3V) = 1.65 +-0.07 sem, +-0.56 stdev ; EEM N=53 HIP A3V d<75pc Mv(A3V) = 1.70 mag ; B/A/F dwarf sequence for B-V=0.10 Mv(A3V) = 1.72 mag ; anchor stan. HD 216956 = Alf PsA Mv(A3V) = 1.81 mag ; exemplar HD 51693 = HR 2606 Mv(A3V) = 1.82 mag ; exemplar HD 52859A Mv(A3V) = 1.91 mag ; ter. stan. HD 23643 = Cl Melotte 22 1425 (Pleiad) Mv(A3V) = 1.93 mag ; pri. stan. HD 102647 = bet Leo Mv(A3V) = 1.96 mag ; exemplar HD 52859B Mv(A3V) = 2.0 mag ; GrayCorbally09 Mv(A3V) = 2.09 mag ; ter. stan. BD+48_944 = Cl Melotte 20 970 (alpha Per cluster) => adopt Mv(A3V) = 1.70 mag [updated 9/24/2020] => adopt M_G(A3V) = 1.69 mag [updated 12/10/2020] (Mv=1.70, G-V=-0.01) => adopt M_Ks(A3V) = 1.447 mag [updated 12/30/2020] (Mv=1.70, V-Ks=1.447) logL(A3V) = 1.602 dex ; Zorec12 median logL(A3V) = 1.258 dex ; sec. stan. HD 135379 = bet Cir logL(A3V) = 1.232 dex ; Mv=1.70 + BCv=-0.04 => Mbol = 1.660 logL(A3V) = 1.223 dex ; anchor stan. Fomalhaut (Mamajek12) logL(A3V) = 1.149 dex ; ter. stan. HD 23643 = Cl Melotte 22 1425 (Pleiades member) logL(A3V) = 1.141 dex ; pri. stan. HD 102647 = bet Leo logL(A3V) = 1.077 dex ; ter. stan. BD+48_944 = Cl Melotte 20 970 (alpha Per cluster) => adopt logL(A3V) = 1.232 dex [updated 9/24/2020] => adopt Mbol(A3V) = 1.660 mag [updated 9/24/2020] Mass(A3V) = 2.29 Msun ; Zorec12 median Mass(A3V) = 2.281+-0.016 Msun ; Eclipsing binary V1031 Ori B (Torres10) Mass(A3V) = 2.02 Msun ; EEM Teff vs. Mass fit for binaries (Teff=8600K) Mass(A3V) = 1.95 Msun ; EEM Mv vs. Mass fit for binaries (Mv=1.5) Mass(A3V) = 1.92 Msun ; Ekers18 ML calibration for logL=1.232 Mass(A3V) = 1.92 Msun ; EEM logL vs. Mass fit for binaries (logL=1.232) Mass(A3V) = 1.92 Msun ; pri. stan. Fomalhaut (Mamajek12) Mass(A3V) = 1.901+-0.019 Msun ; Eclipsing binary V396 Cas B (Torres10) Mass(A3V) = 1.90 Msun ; HenryMcCarthy93 for Mv=1.7 => adopt Mass(A3V) = 1.92 Msun [updated 12/29/2019] Rad(A3V) = 1.672 Rsun ; pri. stan. HD 102647 = bet Leo Rad(A3V) = 1.688 Rsun ; ter. stan. BD+48_944 = Cl Melotte 20 970 (alpha Per cluster) Rad(A3V) = 1.835 Rsun ; ter. stan. HD 23643 = Cl Melotte 22 1425 (Pleiades member) Rad(A3V) = 1.842 Rsun ; anchor stan. Fomalhaut (Mamajek12 & updated) Rad(A3V) = 1.861 Rsun ; logL=1.232 ,Teff=8600K Rad(A3V) = 1.892 Rsun ; sec. stan. HD 135379 = bet Cir => adopt Rad(A3V) = 1.861 Rsun [updated 9/24/2020] # No Standard Morgan65 does not list an A3V standard # Anchor Standard HD 216956 = alf PsA = HR 8728 A3V: MK43(stan),JM53,MK73,Garrison79(stan),Cucchiaro80,Garrison94,HoukStandard *A3Va: GrayGarrison89,Garrison96 A3: Cannon24(standard),Bidelman85 A4V: Gray06 GrayGarrison89 list it as one of two low-vsini A3Va standards (with bet Leo). I dismiss the A4V type by Gray06 which has unfortunately started to pervade the literature as Fomalhaut is an anchor standard for A3V (A3 going back to Cannon) - unless somehow Fomalhaut is spectrally variable (which hasn't been reported). Common proper motion companion with K4V standard TW PsA (Fomalhaut B) and Mamajek13 reports tertiary Fomalhaut C (M4V). No astrometry in Gaia DR2 or EDR3. plx=129.81+-0.47mas(HIP2). V=1.155+-0.005(Mermilliod91), V=1.17(HIP), B-V=0.145+-0.011(HIP), 0.011, B-V=0.094+-0.005(Mermilliod91), U-B=0.100+-0.037(Mermilliod91), V-I=0.16+-0.01(HIP). Mamajek12 derives the following parameters: Radius=1.842+-0.019 Rsun. logL=1.221+-0.013. Mass=1.92+-0.02Msun. Age=440+-40 Myr. Teffs: 7671K(Luck17), 8399K(Gray06), 8459K(Boyajian12), 8500K(Dunkin97), 8590+-73K(Mamajek12), 8610K(Zorec12), 8622K(Blackwell98), 8689K(Erspamer03), 8715K(Ammler-von Eiff12), 8900K(Sokolov95), 9143K(David15) => = 8610K. Luminosity: V=1.155, plx=129.81, BCv=-0.04, Av=0.00 => Mv=1.72, Mbol=1.68, logL=1.223 => w/Teff=8610K => Rad = 1.838 Rsun. # Primary Standard HD 102647 = bet Leo = HR 4534 = Denebola = HIP 57632 A3V: Maury1897,MK43,JM53,Osawa59,Cowley67,Palmer68,Cowley69(stan),Barry70,Houk(standard),Abt95,GrayAtlas *A3Va: GrayGarrison89,Garrison96 A2: Bidelman85 A4V: Adams35 A5V: Cucchiaro80 GrayGarrison89 list it as one of two low-vsini A3Va standards (w/ Fomalhaut). plx=90.16+-0.89mas(HIP), plx=90.91+-0.52mas(HIP2). V=2.14(Johnson66,HIP), V=2.135+-0.012(Mermilliod91), B-V=0.08(Johnson66), B-V=0.090+-0.000(HIP), B-V=0.091+-0.010(Mermilliod91), U-B=0.07(Johnson66), U-B=0.076+-0.021(Mermilliod91), V-I=0.10+-0.00(HIP). 2MASS photometry poor. Teffs: 8378K(Gray03), 8421K(Boyajian13), 8501K(Stassun18), 8531K(Zorec12), 8570K(Erspamer03), 8604K(Boyajian13), 8690K(Philip80), 8720K(Sokolov95), 8750K(Chen14), 8759+-158K(vanBelle09), 9186K(David15) => = 8608K. logg=4.22(Gray03),4.26(Erspamer03). vsini=124km/s(Erspamer03). [M/H]=0.00(Gray03). Luminosity: V=2.135, plx=90.91, Av=0.00, BCv=-0.04 => Mv=1.93, Mbol=1.89, logL=1.141 => w/Teff=8608K => Rad=1.672Rsun. # Secondary Standards: HD 135379 = bet Cir = HR 5670 = GJ 580.1 = HIP 74824 A2/3IV/V: Houk75 A3V: 1955MmMtS..12....1W,Evans57,Levato72,Abt95 A3Va: Gray06 *A3Vb: GrayGarrison89 A3IV: DeVaucouleurs57 A5V: 1978A&AS...35...75C Pretty consistent classification as A3V or variant. GrayGarrison89 list it as their low-vsini A3Vb standard, but called it A3Va in Gray06. Member of Argus group? (Ujjwal20). Mittal15: IR excess L_IR/L_star = 5.40e-5. plx=33.75+-0.75mas(HIP), plx=32.73+-0.19mas(HIP2). V=4.07(HIP), V=4.061+-0.011(Mermilliod91), B-V=0.088+-0.007(HIP), B-V=0.092+-0.008(Mermilliod91), B-V=0.101+-0.003(TYC), V-I=0.08+-0.02(HIP), U-B=0.084+-0.005(Mermilliod91). Teffs: 7694K(Ballering17), 8213K(GaiaDR2), 8565K(Blackwell98), 8581K(Stassun18), 8641K(Gray06), 8670K(Andrievsky02), 8689K(Erspamer03), 8750K(Mittal15,Chen14), 8857K(diBenedetto98), 8962K(David15) => = 8656K. logg=4.2+-0.2(Andrievsky02), logg=4.21(Erspamer03), [Fe/H]=0.12+-0.19(Andrievsky02), [Fe/H]=0.2(Erspamer03), [Fe/H]=0.22+-0.06(Gaspar13). Mv=1.64. Age=166Myr(Mittal15), 465Myr(David15,avg), 536Myr(Nielsen19). Mass=1.93Msun(Nielsen19). Luminosity: V=4.061, plx=32.73mas, Av=0.00, BCv=-0.04 => Mv=1.64, Mbol=1.60, logL=1.258 => w/Teff=8656K => Rad=1.892Rsun. # Tertiary Standards: HD 23643 = Cl Melotte 22 1425 = HII 1425 (Pleiades member) A1: Binnedijk46 *A3Van: GrayGarrison89(stan) A3V: Adams35 A3.5V: Abt78 A5V: Atanasijevic58 GrayGarrison89 list it as their high-vsini A3Va standard, but not considered a standard previously. Position and proper motion are both consistent with Pleiades membership: Tycho-2 proper motion: pmRA, pmDec = 21.7+-1.3, -43.0+-1.2 mas/yr (Pleiades mean is +19.6, -45.0 mas/yr), and Gaia parallaxes confirm it is in the cluster: plx=7.6049+-0.0602mas(GaiaDR2), plx=7.4730+-0.0316mas(GaiaEDR3). Pleiades mean E(B-V)=0.04. Soderblom09 mean [Fe/H] for Pleiades is +0.042+-0.021. V=7.768+-0.012(Mermilliod91), V=7.79(TYC), B-V=0.156+-0.005(Mermilliod91), U-B=0.120+-0.000(Mermilliod91). Dereddening the U-B and B-V colors to the dwarf sequence yields (remarkably to chi^2=0.001): E(B-V)=0.07, (B-V)o=0.086 - hence it is slightly more reddened than the mean for Pleiades (E(B-V)=0.04). Teff: 7420+-305K(Kounkel19), 7440+-147K(Ilin19), 7995+248-136K(GaiaDR2), 8000+-125K(Buoy15), 8066+-225K(Bai19), 8226K(Stassun18), 8258+-134K(David15), 8352+-506K(Huber17), 8454K(Stauffer16), 8474K(Anders19), 8704+-262K(Stassun19), 9615+-427K(Johnsson20), 10076K(Queiroz20) => = 8258K. Luminosity: V=7.768, BCv=-0.04, Av=0.229, plx=7.4730 => Mv=1.91, Mbol=1.87, logL=1.149 => w/Teff=8258K => Rad=1.835Rsun. BD+48_944 = Cl Melotte 20 970 = HIP 16452 (alpha Per cluster) A2: Heckmann58 *A3V: MK78,Keenan85 A4V: Petrie69 A5V?: Morgan71 Fairly weak pedigree as a standard goes, but used in MK78 atlas. V=8.19(Mermilliod91), V=8.212(Pickles10,fit), V=8.22(HIP), (B-V)=0.185+-0.003(HIP), (B-V)=0.187(Mermilliod91), U-B=0.130(Mermilliod91), V-I=0.20+-0.00(HIP). plx=6.6782+-0.0504mas(GaiaDR2), plx=6.6904+-0.0293mas(GaiaEDR3). E(B-V)=0.077(Kervella19,STILISM) => adopt (B-V)o=0.108, Av=0.253. Stassun19 lists E(B-V)=0.0346+-0.0396. Teffs: 7660+-200K(Kounkel19), 7974+-259K(Bai19), 8227+-378K(Stassun19), 8235K(GaiaDR2), 8286K(Queiroz20), 8461K(Anders19), 8799+-141K(David15), 9066K(Stassun18) => = 8261K. Luminosity: V=8.212, BCv=-0.04, Av=0.253, plx=6.6904mas => Mv=2.09, Mbol=2.05, logL=1.077 => w/Teff=8261K => Rad=1.688Rsun. # Deprecated Standards: 38 Lyn = HD 80081 = HR 3690 A1V: Abt95 *A1V+A4V: Palmer68 A2V: Osawa59,Cucchiaro78 A2 (MgII: A3): Baschek78 A2IV-: GrayGarrison87 A3V: MK43,Cowley69(stan) 2.5" binary(V=3.9+6.0), which Palmer68 splits as A1V+A4V. And then WDS reports that A is a spectroscopic binary and B has been resolved into a ~0.1-0.2". Along with E component ~98" away, this is at least a quintuplet, with at least 4 components within 2.5" of each other. Cucchiaro80 lists "A lambda Boo" in Skiff compendium. Zet Vir = HR 5107 = HD 118098 (V=3.4) A1: Bidelman85 *A2Van: Gray03 A2IVn: Abt95 A2IV-: GrayGarrison87 A3V: Maury1897(A3),MK43,Cowley69(stan),Levato72,Cucchiaro80 HD 56537 = Lam Gem = 54 Gem = HR 2763 A3V: JM53,Cowley69(stan) *A4IV: GrayGarrison89(for "AB") HD 106591 = Del UMa A3V: MK43, Jaschek64(all),Cowley69(stan),Jaschek78(JM53) *A2Vn: Gray03,Abt95,GrayGarrison87(A2Van),Cannon(A2) Migrated from A3V (MK/JM53) to A2V (Gray/Garrison/Abt) - probably not good standard. 22 Com = HR 4780 = HD 109307 = Coma T183 = Cl Melotte 111 183 = HIP 61925 A2III: 1953UppAn...3j...1W A3V: Abt68 A3s: Trumpler38 A4V: Abt72 A4m: Weaver52 Coma "T"# presumably from Trumpler38 (the default counting for Coma members both in WEBDA and SIMBAD). Trumpler lists #183 has having photographic magnitude 6.25 and type "A3s" and Harvard/HD-type as A2. This is perfect match. So "T183" in Abt68 = Cl Melotte 111 183. B-V=0.11(Renson09), U-B=0.10(Renson09). # Exemplars HD 23848 = HR 1177 A1IV pec: Palmer68 A2V: Osawa59 *A3V: Slettebak60(A3),Cowley69,1978A&AS...33...15C,Abt95 V=5.14(HIP),B-V=0.057+-0.002(HIP), plx=12.15+-0.70mas(vanLeeuwen07), Mv=0.56. HD 31283 = HR 1569 = HIP 22833 *A3V: Palmer68,Cowley69,Abt95 All three published types A3V. V=5.18(HIP), B-V=0.121+-0.005(HIP), plx = 14.2064+-0.2127mas(GaiaDR2) => Mv=0.94. HD 51693 = HR 2606 A2V: Abt95 *A3V: Palomar68,Cowley69,Paunzen01(A3V (met wk)) V=6.25(HIP), B-V=0.105+-0.005(HIP), plx=14.64+-0.47mas(vanLeeuwen07), plx=12.9564+-0.0460mas(GaiaDR2) => Mv=1.81. GaiaDR2 splits as binary with G=6.2357 and G=11.4209. HD 52859AB = HR 2644 A3V: Cucchiaro78(S2/68 spectra) *A3Va+A3Va: GrayGarrison89 A2IV-V+A2V: Abt95 WDS: 4.4" pair, V(A)=6.87, V(B)=7.01, V(AB)=6.17(HIP). GarrisonGray87 call both A3Va. plx(A)=9.8947+-0.0570mas(GaiaDR2), plx(B)=9.7648+-0.0777(GaiaDR2) => adopt plx(AB) = 9.83 mas => D = 102 pc. E(B-V)=0.004+-0.015(STILISM) => adopt Av=0.012. B-V(AB)=0.102 => (B-V)o(AB) = 0.102 - 0.004 = 0.098. Mv(A)=1.82, Mv(B)=1.96. HD 151431 = 19 Oph = HR 6232 A3V: Cowley69,Jaschek91(A3V shell),Abt95 V=6.07(HIP), B-V=0.140+-0.005(HIP), E(B-V)=0.070+0.014-0.039(Kervella19,STILISM) => adopt Av=0.22, (B-V)o= 0.07. plx=4.5639+-0.0833mas(GaiaDR2) => 219+-4 pc. Mv=-0.85. # Other Stars Morgan65 classified one A3V Hyad: HD 27962 (B-V = 0.049 +- 0.007; HIP), but this star was later classified A2IV-Vs by GrayGarrison87 and A2IV by Abt95.