AA0V Garrison94 lists two A0V anchor standards (gam UMa (=HD 103287) & alf Lyr (= HD 172167 = Vega)), and MK73 lists the same two A0V stars as dagger standards (gam UMa & alf Lyr). MK43 standard: gam UMa, alf Lyr, alf CrB, 30 Mon(check this one?) JM53 standard: gam Uma, alf Lyr, alf CrB, 4 Aur, HR 3314, 109 Vir, HR 5859, HR 6070, gam Oph Morgan65 standard: gam UMa - A0V Garrison67 standard: alf CrB - A0V Abt68 standard: gam UMa - A0V Cowley69 standards: alf CrB, gam Oph, gam UMa, & 109 Vir - A0V Cowley72 standards: alf CrB, gam Oph, gam UMa - A0V MK73 standard: alf Lyr - A0V Houk75 standard: gam UMa - A0V (primary standard) MK78 standard: alf Lyr - A0Va, HD 66656 (= NGC 2516 #29) - A0Vb Garrison79 standards: HR 3314 & HD 147013 - A0V Keenan85 standard: alf Lyr - A0V Gray87 standard: alf Lyr - A0Va gam UMa - A0Van chi Cap - A0Van HD 225047 - A0Vb HR 3314 (HD 71155; see 1988 erratum) - A0Va Garrison94 anchors: alf Lyr, gam UMa - A0V WiegertGarrison98 st.: 109 Vir, gam Oph - A0V GrayAtlas standard: alf Lyr - A0Va GrayNstars standard: alf Lyr, HR 3314 - A0Va (and non-standard HD 225047 for A0Vb) Gray87 has an extensive discussion on early A-type standards. Gray 87 lists 5 A0V standards of various flavors: HD 225047 (A0Vb), Alf Lyr and HD 71151 (A0Va; originally incorrectly listed as "HD 71155", see erratum), Gam UMa and Chi Cap (A0Van). They consider rapid rotation (n) to be vsini > 150 km/s. Skiff20 lists only three A0V standards: HD 103287 (gam UMa; MK73), 172167 (alf Lyr; MK78), 66656 (MK78). For A0V Hipparcos stars within 75pc, with parallax S/N > 8, and within 1 mag of the MS (N=15): (A0V) = 0.027 (+-0.012 sem, +-0.061 stdev; N=15) (A0V) = 0.013 (+-0.015 sem, +-0.066 stdev; N=15) (A0V) = 0.031 (+-0.019 sem, +-0.071 stdev; N=15) (A0V) =-0.002 (+-0.010 sem, +-0.039 stdev; N=15) (A0V) = 0.021 (+-0.011 sem, +-0.036 stdev; N=15) (A0V) = 0.018 (+-0.012 sem, +-0.042 stdev; N=15) (A0V) = 0.010 (+-0.008 sem, +-0.025 stdev; N=15) (A0V) = 0.029 (+-0.025 sem, +-0.083 stdev; N=15) (B-V)(A0V) = 0.067 ; BakisEker22 (how could mean B-V for A0Vs be 0.067 when BV system was *defined* to have zero B-V for A0Vs?!) (B-V)(A0V) = 0.044 ; pri. stan. gam UMa (A0V) = 0.015 (+-0.011 sem, +-0.034 stdev (EEM HIP d<75pc S/N>8; N=15) (B-V)(A0V) = 0.012 ; Crawford76 (B-V)(A0V) = 0.002 ; sec. stan. HD 225047 (B-V)(A0V) = 0.002 ; smoothed trend SpT vs (B-V)o B9.5V-F3V 11/2021 (B-V)(A0V) = 0.00 ; JohnsonMorgan53(def), Morgan53, Johnson63, Johnson66, KenyonHartmann95 (B-V)(A0V) = 0.00 ; Garrison67, Morgan71 (B-V)(A0V) = 0.00 ; anchor stan. Vega (B-V)(A0V) = -0.01 ; Fitzgerald70 (B-V)(A0V) = -0.01 ; Davidson87 (analysis of BSC A0V stars) (B-V)(A0V) = -0.012 ; prim. stan. HR 3314 (A0V) = -0.013 (+-0.012 sem, +-0.010 stdev) ; Gray01/03/06 N=3 A0Vs (B-V)(A0V) = -0.015 (+-0.064 rms) ; d<60 pc SIMBAD A0V N=12 (B-V)(A0V) = -0.020 ; Bessell79 (B-V)(A0V) = -0.02 ; Schmidt-Kaler82 Johnson53 defined B-V = 0.00 based on colors of sample of A0V stars. => adopt (B-V)(A0V) = 0.000 *** [last updated 11/21/2021] => adopt (U-B)(A0V) = -0.005 (see below) => adopt (V-I)(A0V) = 0.004 => adopt (V-R)(A0V) = 0.001 => adopt (R-I)(A0V) = 0.003 => adopt (V-J)(A0V) = 0.046 => adopt (V-H)(A0V) = 0.013 => adopt (V-Ks)(A0V) = 0.041 => adopt (H-Ks)(A0V) = 0.028 => adopt (J-H)(A0V) = -0.032 (Bp-Rp)(A0V) = -0.037 ; color trend for B-V=0.00 (Bp-Rp)(A0V) = -0.006 ; Evans18 trend for V-I= 0.004 => adopt(Bp-Rp)(A0V) = -0.037 [updated 11/22/2020] (Bp-G)(A0V) = -0.027 ; color trend for B-V=0.00 => adopt (Bp-G)(A0V) = -0.027 [updated 11/22/2020] (G-Rp)(A0V) = -0.020 ; color trend for B-V=0.00 => adopt (G-Rp)(A0V) = -0.020 [updated 11/22/2020] (Ks-W1)(A0V) = 0.042 ; EEM trend for d<30pc for B-V=0.00 => adopt (Ks-W1)(A0V) = 0.042 [updated 12/29/2019] (G-V)(A0V) = -0.023 ; polynomial fit f(B-V) (G-V)(A0V) = -0.005 ; * kap And PM* A0V (G-V)(A0V) = -0.002 ; * tet Lep * A0V (G-V)(A0V) = 0.007 ; * eps Mic PM* A0V (G-V)(A1V) = 0.01 ; adopted for A1V (G-V)(A0V) = 0.010 ; * gam Aqr PM* A0V (G-V)(A0V) = 0.010 ; HD_20911 A0V (G-V)(A0V) = 0.010 ; HD_125987 A0V (G-V)(A0V) = 0.012 ; HD_210267 A0V (G-V)(A0V) = 0.014 ; * phi Oct * A0V (G-V)(A0V) = 0.015 ; HD 42818 PM* A0Vn (G-V)(A0V) = 0.017 ; fit for A dwarfs from Kervella19 corrected for E(B-V), eval for (V-Ks)=0.041 (G-V)(B9.5V) = 0.017 ; adopted for B9.5V (G-V)(A0V) = 0.017 ; HD_207204 A0V (G-V)(A0V) = 0.018 ; HD_107947 A0V (G-V)(A0V) = 0.025 ; HD_52534 A0V (G-V)(A0V) = 0.028 ; HD_46190 A0V (G-V)(A0V) = 0.036 ; HD_41835 A0V (G-V)(A0V) = 0.045 ; HD 125987 * A0V (G-V)(A0V) = 0.073 ; * gam01 Ari PM* A0Vnp_lB => adopt (G-V)(A0V) = 0.015 [updated 4/8/2022] (U-B)(A0V) = +0.014 ; prim. stan. gam UMa (U-B)(A0V) = 0.00 ; JohnsonMorgan53(def),Johnson63 (U-B)(A0V) = -0.006 ; prim. stan. Vega (U-B)(A0V) = -0.005 ; HIP d<75pc S/N>8 A0V N=35 (Mermilliod91 photometry) (U-B)(A0V) = -0.02 ; prim. stan. HR 3314 (U-B)(A0V) = -0.02 ; Fitzgerald70 Johnson53 defined U-B = 0 color based on sample of A0V stars. => adopt (U-B) = -0.005 [ (A0V) = -0.021 (+-0.011 sem, +-0.010 stdev) ; Gray01/03/06 N=3 A0Vs (A0V) = -0.02 ; Bessell79 (A0V) = 0.026 (+-0.010 sem, +-0.036 stdev) ; HIP d<75 S/N>8 N=15) (R-I)(A0V) = -0.012 ; Bessell79 (g-r)(A0V) = -0.104 ; Jordi06 (V-R)=>(g-r) for V-R=0.001 (g-r)(A0V) = -0.250 ; Covey07 (g-r)(A0V) = -0.252 ; Bilir05 (B-V)=>(g-r) for B-V=0.00 => adopt (g-r)(A0V) = -0.25 [updated 10/10/2020] Teff(A0V) = 10040 K ; GrayCorbally94 Teff(A0V) = 10000 K ; Crowther97/Fig.3 Teff(A0V) = 10000 K ; Bessell79 Teff(A0V) = 9886 K ; Bessell98 Teff(A0V) = 9800 K ; GrayCorbally09 Teff(A0V) = 9800 K ; Blackwell80 Teff(A0V) = 9784 K ; B-V=0.00 => Teff(Bessell98,logg=4.3) Teff(A0V) = 9780 K ; Bertone04[ATLAS] Teff(A0V) = 9750 K ; Zorec12 median Teff(A0V) = 9740 K ; prim. stan. HR 3314 median Teff Teff(A0V) = 9730 K ; Bertone04[NextGen] Teff(A0V) = 9707 K ; EEM N=265 Teffs Teff(A0V) = 9706 K ; median for N=72 Gerbaldi99 A0V stars, Kunzli97 calibration Teff(A0V) = 9660 K ; anchor stan alf Lyr (Monnier13, apparent Teff) Teff(A0V) = 9560 K ; Chavez95 (+60-80K) Teff(A0V) = 9530 K ; Theodossiou90 Teff(A0V) = 9520 K ; Schmidt-Kaler82 Teff(A0V) = 9500 K ; mean photometric Teff Teff(A0V) = 9394 K ; Boyajian12 Teff(A0V) = 9377 K ; B-V=0.00 => Teff(Napiwotski93) Teff(A0V) = 9355 K ; prim. stan. gam UMa (see below) => adopt Teff(A0V) = 9700 K (logT = 3.987) [updated 9/16/2019] BCv(A0V) = -0.267 ; Flower96(Teff=9700K, set BCv(5772K)=-0.085) BCv(A0V) = -0.231 ; Code76(Teff=9700K, set BCv(5772K)=-0.085) BCv(A0V) = -0.218 ; Bessell98(ATLAS,logg=4.0,Teff=9700K, set BCv(5772K)=-0.085 BCv(A0V) = -0.213 ; Balona94(Teff=9700K, set BCv(5772K)=-0.085 BCv(A0V) = -0.209+-0.015 ; calc using Calspec Vega, IAU2015 mbol scale, V=0.028+-0.003 for Vega BCv(A0V) = -0.170 ; Schmidt-Kaler82(BCv=-0.30 + 0.13 offset) BCv(A0V) = -0.164 ; Bertone04[ATLAS,Teff=9700K, set BCv(5772K)=-0.085 => adopt BCv(A0V) = -0.21 [updated 9/16/2019, adjusted so that BCv(5772K)=-0.085] Mv(A0V) = 1.53 mag ; sec. stan. HD 225047 (in Blanco 1) Mv(A0V) = 1.4 mag ; GrayCorbally09 Mv(A0V) = 1.26 mag ; deprecated stan. gam Oph (HD 161868) Mv(A0V) = 1.14 +-0.11(sem),+-0.55(st.dev.) ; EEM N=44 HIP A0V d<75pc |dMv|<1 Mv(A0V) = 1.14 mag ; median Mv for A0V calc using Kervella19 HIP & Gaia DR2 (d<100pc) Mv(A0V) = 1.113 mag ; Wright05(B-V=0.00) Mv(A0V) = 1.04 mag ; pri. stan. HR 3314 Mv(A0V) = 1.02 mag ; interp BAF dwarf seq for B-V=0.00 Mv(A0V) = 0.99 mag ; B/A/F sequence for B-V=0.00 Mv(A0V) = 0.97 mag ; linear B-V vs. Mv fit to d<50pc Gray01/03/06 dwarfs for B-V=0.00 Mv(A0V) = 0.95 mag ; d<60 pc Mv(B-V=0.00) Mv(A0V) = 0.95 mag ; d<60 pc SIMBAD A0V N=12 Mv(A0V) = 0.69 mag ; Wegner07 Mv(A0V) = 0.71 mag ; EEM trend to d<60pc dwarfs for B-V=0.00 Mv(A0V) = 0.682 +-0.133(sem),+-0.95(stdev) ; EEM N=44 vetted A0V stars Gerbaldi (HIP, mag selected ) Mv(A0V) = 0.60 mag ; anchor stan. Vega Mv(A0V) = 0.6 mag ; Schmidt-Kaler82 Mv(A0V) = 0.38 mag ; pri. stan. gam UMa => adopt Mv(A0V) = 0.99 mag [updated 9/24/2020] => adopt M_G(A0V) = 1.00 mag [updated 12/10/2020] (Mv=0.99, G-V=0.01) => adopt M_Ks(A0V) = 0.949 mag [updated 12/30/2020] (Mv=0.99, V-Ks=0.041) logL(A0V) = 1.584 dex ; adopt Mv=0.99 + BCv=-0.21 => Mbol = 0.780 logL(A0V) = 1.591 dex ; logL/Teff trend for OB-A1V dwarf EBs (Torres10; Teff=9700K) logL(A0V) = 1.627 dex ; pri. stan. gam UMa (Jones15) logL(A0V) = 1.674 dex ; anchor stan. Vega (Monier13) logL(A0V) = 1.738 dex (+-0.054 sem, +-0.359); N=48 vetted A0V stars from Gerbaldi99 (mag-limited, not Vol-limited) logL(A0V) = 1.76 dex ; Zorec12 median => adopt logL(A0V) = 1.584 dex [updated 12/27/2020] => adopt Mbol(A0V) = 0.780 mag [updated 12/27/2020] Note: Gerbaldi99 demonstrates that there are stars classified A0V between logL ~ 1.3 to 2.6! Mass(A0V) = 2.57 Msun ; Zorec12 median Mass(A0V) = 2.572 Msun ; Vega (mean of pole 2.418Rsun, eq 2.726 Rsun) Mass(A0V) = 2.52 (+-0.07 sem,+-0.39 stdev) ; N=48 Gerbaldi99 vetted A0V stars (but mag-limited sample) Mass(A0V) = 2.482+-0.025 Msun ; Eclipsing binary TZ Men A (Torres10) Mass(A0V) = 2.351+-0.052 Msun ; Eclipsing binary V451 Oph B (Torres10) Mass(A0V) = 2.39 Msun ; EEM Mv vs. Mass fit for binaries (Mv=1.0) Mass(A0V) = 2.38 Msun ; EEM Teff vs. Mass fit for binaries (Teff=9700K) Mass(A0V) = 2.34 Msun ; Bertelli09 solar tracks for Teff=9700K,logL=1.58 Mass(A0V) = 2.32 Msun ; EEM logL vs. Mass fit for binaries (logL=1.58) Mass(A0V) = 2.3 Msun ; Vega (Aufdenberg06) Mass(A0V) = 2.30 Msun ; Ekers18 ML calibration for logL=1.58 Mass(A0V) = 2.15+0.10-0.15 Msun ; Vega (Monnier13) Mass(A0V) = 2.135 Msun ; Vega (Yoon10) Mass(A0V) = 1.905+-0.040 Msun ; Eclipsing binary AY Cam A (Torres10) => adopt Mass(A0V) = 2.35 Msun [updated 12/29/2019] Rad(A0V) = 2.572 Rsun ; anchor stan. Vega (mean radius) Rad(A0V) = 2.193 Rsun ; logL=1.584,Teff=9700K => adopt Rad(A0V) = 2.193 Rsun [updated 9/24/2020] # Anchor Standard HD 172167 = alf Lyr = Vega A0V: MK43,JM53,MK73,MK78,Keenan85,Garrison94(anchor),GrayAtlas *A0Va: Gray87(stan),Garrison96 Gray87 uses it as the primary low vsini A0Va standard (from MK78). V=0.03(HIP, Johnson66), B-V=-0.001+-0.005(HIP), B-V=0.00(Johnson66), U-B=0.00(Johnson66), U-B=-0.006+-0.006(Mermilliod91), V-I=-0.01+-0.02(HIP), K=-0.02(Gehrz74, Gehrz76, Grasdalen83), K=0.02(Johnson66), Ks=-0.036+-0.010(Reike08,indirectly). f_bol: (2983+-120)e-8 erg/cm^2/s (Alonso94; erroneously cited as "(2983+-120)e-8 erg/cm^2/s" in Ciardi01), 2.983e-5 erg/cm^2/s (Alonso95). Reike08 concludes "this star is not suitable to define a photometric zero-point because of its eccentric SED for its spectral type" (i.e. due to pole-equator Teff difference and possible K-band excess due to a warm disk). Many published Teffs - I find median published Teff = 9468K (N=21). New interferometric study by Monnier13 finds: Lum=47.2+-2.0Lsun => logL=1.6739+-0.0184. Age = 700+150-75 Myr, Mass = 2.15+0.10-0.15 Msun, Rpol=2.418+-0.012Rsun, Req=2.726+-0.006 => =2.572Rsun. Monnier13 quotes several Teff values: Teff(pole)=10070+-90K, Teff(equator)=8910+-130K, Teff(apparent)=9660+-90K, Teff(surface-averaged)=9360+-90K. Presumably the "apparent" Teff=9660K is what one would quote for the apparent spectrum and colors, but Teff=9360K is what one would use to plot the star on the HR diagram. However, Bohlin07 finds that a Kurucz model with 9400K is the best fit to the UV-through-IR SED shape. Rotation period is 0.71+0.03 days (Petit10, Alina12), vsini=22+-2 km/s (Takeda08). Teffs: 9550K(Castelli94), 9550K(Fitzpatrick10), 9553K(Ciardi01) 9560+-30K(Hill10), 9660K(Monnier13). I adopt the Monnier13 averaged value (9660K). Using the Calspec alpha_lyr_stis_006 spectrum from Bohlin07, I sum up the flux using trapezoidal rule and find: f_bol(Vega) = 3.018e-8 W/m^2 (+-1.16%) = 3.018e-5 erg/s/cm^2/A = (3018+-35)e-8 erg/cm^2/s. This translates to an apparent bolometric magnitude mbol(Vega) = -0.182+-0.013 mag. When adopting the Bohlin07 Vmag (0.023+-0.008), this translates to a bolometric correction of BCv(Vega) = -0.205+-0.015 mag. # Primary Standard HD 103287 = gam UMa = HR 4554 = Phecda A0V: MK43,JM53,Morgan65,Abt68,Cowley69(stan),MK73,Houk,Garrison94(anchor) *A0Van: Gray87(stan),Garrison96 A1IV(n): Gray03 A1V: Levato78 I only give slightly more weight to Vega as A0V standard over gamma UMa, as Vega was listed in MK73 and MK78, while gamma UMa was not. Gray87 uses it as the primary high vsini A0Va standard (from MK78), but then calls it A1IV(n) in Gray03. Astrometric binary with K2V companion, which might be resolved in GaiaDR2? (there is no GaiaDR2 entry for gam UMa, but there is a G=7.29 object with heavily contaminated photometry 1.7" away in DR2 with plx =29.4871+-1.0189). Jones15 presents interferometry data and modeling and evolutionary fit. Ursa Major cluster member (~0.5 Gyr), plx = 39.21+-0.40 mas(HIP2). 2MASS photometry is saturated. V=2.41(HIP), B-V=0.044+-0.003(HIP), V-I=0.06+-0.00(HIP), K=2.37(Johnson66,Arizona), K=2.32(Gehrz74, where K(Vega)=-0.02). U-B = 0.014+-0.008 (Mermilliod91). Mv = 0.38(HIP,HIP2). Teffs: 7725+-7K(Bermejo13), 8873K(B-V=>Bessell98), 9272K(Gray03), 9311K(Zorec12,Stassun18), 9355K(King03), 9361+-139K(Wu11), 9390K(Sokolov95), 9692K(Philip80), 10027K(David15), => = 9355K. logg=3.64(Gray03), 3.85+-0.07(Wu11). [M/H]=-0.19(Gray03), -0.44+-0.09(Wu11). Rad=2.557+0.077-0.079Rsun(Jones15), Mass=2.348+0.055-0.060Msun(Jones15), Lum(apparent)=66.94+5.55-5.34Lsun(Jones15) => logL(app)=1.8257+-0.0354(Jones15). Lum(total)=42.37+3.47-3.34Lsun(Jones15) => logL(tot)=1.6271+-0.0350(Jones15). HD 71155 = HR 3314 = C Hya A0V: MK43, JM53, Cowley69, Levato72, Garrison79(stan), Abt95 *A0Va: GrayGarrison87(stan), Houk99(Garrison), Gray03 Everyone has considered this star an A0V or variant. GrayGarrison87 uses it as a "suitable secondary standard" for A0Va (with Vega the primary) See 1988 erratum -- it was incorrectly listed as HD 71151 (phi^2 Cnc) originally. vsin=130km/s. HR3314 is the zero-point of the ESO IR photometric system (van der Bleik+ 1996), where they adopt V=3.89, (V-Ks)=-0.05, J-K=-0.01, H-K=-0.01, K-L'=0.00, K-M=0.00. plx=26.66+-0.19mas(HIP2). Hipparcos lists V=3.91, B-V=-0.012+-0.003, V-I=-0.02+-0.02. Mv = 1.04(HIP,HIP2). Johnson66 lists V=3.90, B-V=-0.02, U-B=-0.02. Mermilliod91 lists V=3.895+-0.006, B-V=-0.014+-0.008, U-B=-0.020+-0.012. Hauck97 lists b-y=-0.007, m1=0.158, c1=1.026, beta=2.896. Bouchet91 lists for the ESO IR system: J[1.24um]=3.933, H[1.65um]=3.951, K[2.19um]=3.936, L[3.77um]=3.932, M[4.8um]=3.984. vanderBliek96 lists for the ESO IR system J=3.932, H=3.932, K=3.944, L'=3.938, M=3.950. HR 3314 is of course saturated in 2MASS. Teffs: 7620K(Bermejo13), 9118K(GaiaDR2), 9556K(Gray03), 9585K(Prugniel07#2), 9663+-87K(Blackwell98), 9683K(Stassun18), 9718K(Ammler-vonEiff12), 9760K(Katz11), 9793K(Prugniel07#1), 9806K(diBenedetto98), 9910K(Sokolov95), 10000K(Mittal15,Chen14), 10060+-360K(Zorec09), 10281K(David15) => = 9740K. logg=3.78(Katz11), 3.93(Prugniel07#1), 3.81(Prugniel07#2). [Fe/H]=-0.40(Prugniel07#1), -0.76(Katz11), -0.77(Prugniel07#2). # Secondary Standard HD 225047 = HIP 232 = Cl Blanco 1 13 (Blanco 1 member) *A0Vb: GrayGarrison87(stan) A0V: Levato79,Houk82 A1V: Bond71 A0VkA2: Wayman61 Not a standard star until GrayGarrison87, and then as their primary "A0Vb low-vsini standard", but minor disagreement among three previous classifiers. I can find no vsini measurements in any Vizier catalogs. The "b" in "A0Vb" indicates "slightly more extensive wings than the A0 Va MK78 standard \alpha Lyra (Vega)" (Gray & Garrison 1987). V=8.43(HIP), B-V=0.007+-0.004 (HIP), but Plx = 5.18+-1.11 mas (HIP), plx=4.1845+-0.0871mas(GaiaDR2) => D = 239+-5 pc. STILISM predicts E(B-V)=0.005+-0.014. Hence (B-V)o = 0.007 - 0.005 = 0.002, Av ~ 0.006. Mv = 1.53+-0.05. # Deprecated Standards HD 66656 = NGC 2516 29 A0V: MK78(A0Vb),Houk75,Cannon(A0),AbtMorgan69 A0mA1Va: Gray87 A2V: Jaschek64,Jaschek78 "A0Vb" standard in MK78 HD 139006 = alf CrB = HR 5793 B9.5IV: Levato78 A0V: MK43,JM53,Osawa59,Garrison67(stan),Cowley69(stan),Hill75,Loden83,Abt95 A0IV: GrayGarrison87 A1V: Adams35,Zorec09(BCDtype) A1IV: Gray03 A1/2: 1897AnHar..28....1M Eclipsing binary with G-type companion on orbit 17 days (see recent study by Schmitt14: 2016A&A...586A.104S). HD 161868 = gam Oph = 62 Oph = HR 6629 B9V: 1955MmMtS..12....1W,Palmer68 A0V: JM53,Cowley69(stan),Levato72 A0Van: GarrisonGray87 A0Vnp: Abt95 A0III/IV: Maury1897(inSkiff) A1VnkA0mA0: Gray03 V=3.75(HIP), plx=31.73+-0.21mas(HIP2) => Mv=1.26+-0.02. HD 31647 = ome Aur = 4 Aur = HR 1592 B9.0: Klochkova85 A0V: JM53,Palmer68,Barry70, *A1V: Osawa59,Cowley69,Cucchiaro78,GarrisonGray87(A1Va),Abt95,Zorec09(BCDtype) Has V=8.2 F9V companion 5" away. # Other Standards (still assessing quality) HD 130109 = 109 Vir = HR 5511 A0V: JM53, Cowley69(stan) HD 140775 = HR 5859 A0V: JM53 HD 146624 = d Sco = HR 6070 A0V: JM53 HD 147013 A0V: Garrison79(stan) # Other Non-Standard Stars Zet Aql A A0Vann: Garrison96 HD 71151 = phi02 Cnc: was erroneously listed in GrayGarrison87 and corrected in erratum (1988ApJS...68..407G). # Notes (G-V): Using Kervella+2019 catalog (cross-referencing Hipparcos with Gaia DR2, including E(B-V) from STILISM and 2MASS Ks), and using a sample of A dwarfs with HIP2 and Gaia DR2 parallaxes > 5 mas, E(B-V) <= 0.02 mag, G and K errors of <0.03 mag, and correcting photometry using Av=3.1*E(B-V), A_G = 0.9536*Av (LuhmanEsplin20 for low Av), A_Ks=0.382*E(B-V), I derive a fit to the dereddened colors of stars classified as A dwarfs with -0.13 < (V-Ks) < 1.0 of: (G-V) = 1.9070571562909713e-2 - 3.9288365588456699e-2*(V-Ks) - 6.3347152398901291e-2*(V-Ks)^2 (rms=0.0156 mag).