AAA1V Garrison94 does not list any A1V anchor standards, and MK73 does not list a A1V dagger standard. There is an irritating lack of continuity between the standards defined by MK43 and JM53 (zero overlap) MK43 standard: alf CMa - A1V alf Gem A - A1V gam Gem - A1V bet UMa - A1V JM53 standards: HR 875 - A1V HR 1046 - A1V iot Ser - A1V 39 Dra - A1V HR 7784 - A1V eps Aqr - A1V Cowley69 standards: alf Gem - A1V iot Ser - A1V bet UMa - A1V HR 7784 - A1V Houk75 standard: iot Ser - A1V Gray87 standards: HD 10939 - A1Va HD 9132 - A1Va HD 45320 - A1Van GrayNstars standard: HD 45320 (=HR 2324) - A1V Shocking inconsistency between the MK43 and JM53 standards. Isn't there supposed to be some continuity in the standards? For A1V Hipparcos stars within 75pc, with parallax S/N > 8, and within 1 mag of the MS (N=12): (A1V) = 0.109 (+-0.015 sem, +-0.063 stdev; N=12) (A1V) = 0.109 (+-0.032 sem, +-0.084 stdev; N=12) (A1V) = 0.148 (+-0.024 sem, +-0.086 stdev; N=12) (A1V) = 0.066 (+-0.017 sem, +-0.056 stdev; N=12) (A1V) = 0.091 (+-0.017 sem, +-0.054 stdev; N=12) (A1V) = 0.081 (+-0.013 sem, +-0.036 stdev; N=12) (A1V) = 0.022 (+-0.008 sem, +-0.013 stdev; N=12) (A1V) = 0.162 (+-0.033 sem, +-0.097 stdev; N=12) (B-V)(A1V) = 0.005 ; Bessell79 (B-V)(A1V) = 0.01 ; SchmidtKaler82 (B-V)(A1V) = 0.02 ; Fitzgerald70 (B-V)(A1V) = 0.028 ; sec. stan. 48 Cet (B-V)(A1V) = 0.03 ; Morgan53, Johnson63, Garrison67, Morgan71, KenyonHartmann95 (B-V)(A1V) = 0.031 ; pri. stan. HD 10939 (B-V)(A1V) = 0.039 ; smoothed trend SpT vs (B-V)o B9.5V-F3V 11/2021 (B-V)(A1V) = 0.041 ; ter. stan. HD 21447/HR 1046 (B-V)(A1V) = 0.043 ; sec. stan. del Vel (B-V)(A1V) = 0.050 ; d<60 pc SIMBAD A1V N=15 (B-V)(A1V) = 0.05 ; JohnsonMorgan53 (A1V) = 0.055 (+-0.013 sem, +-0.016 stdev) ; Gray01/03/06 (N=4) (A1V) = 0.073 (+-0.011 sem, +-0.033 stdev) ; HIP d<75pc S/N>8 (N=12) (B-V)(A1V) = 0.095 ; BakisEker22 => adopt (B-V)(A1V) = 0.035 *** [last updated 5/24/2019] => adopt (U-B)(A1V) = 0.023 => adopt (V-I)(A1V) = 0.037 => adopt (V-R)(A1V) = 0.016 => adopt (R-I)(A1V) = 0.021 => adopt (V-J)(A1V) = 0.085 => adopt (V-H)(A1V) = 0.060 => adopt (V-Ks)(A1V) = 0.090 => adopt (H-Ks)(A1V) = 0.030 => adopt (J-H)(A1V) = -0.025 [EEM 12/2/2012: standards are tightly clustered around B-V ~ 0.03-0.04, while median for A1V samples have B-V ~ 0.05-0.07. One could probably argue for an adopted value being anywhere from B-V ~ 0.03 to 0.07. Johnson66 omits listing colors for A1V.] (Bp-Rp)(A1V) = 0.037 ; Evans18 trend for V-I=0.037 (Bp-Rp)(A1V) = 0.005 ; color trend for B-V=0.035 => adopt (Bp-Rp)(A1V) = 0.005 [updated 11/22/2020] (Bp-G)(A1V) = -0.036 ; color trend for B-V=0.035 => adopt (Bp-G)(A1V) = -0.036 [updated 11/22/2020] (G-Rp)(A1V) = 0.032 ; color trend for B-V=0.035 => adopt (G-Rp)(A1V) = 0.032 [updated 11/22/2020] (Ks-W1)(A1V) = 0.043 ; EEM trend for d<30pc for B-V=0.035 => adopt (Ks-W1)(A1V) = 0.043 [updated 12/29/2019] (G-V)(A1V) = -0.074 ; * gam TrA PM* A1V (G-V)(A1V) = -0.026 ; * 3 Crv PM* A1V (G-V)(A1V) = -0.012 ; * 50 Cnc PM* A1Vp (G-V)(A1V) = -0.004 ; * psi Sco * A1V (G-V)(A1V) = -0.003 ; * gam Oph PM* A1VnkA0mA0 (G-V)(A1V) = 0.000 ; * gam Tri PM* A1Vnn (G-V)(A1V) = 0.000 ; HD 96819 PM* A1V (G-V)(A1V) = 0.001 ; * b Dra A A1V (G-V)(A1V) = 0.001 ; polynomial fit for f(B-V) (G-V)(A1V) = 0.004 ; * 33 Boo PM* A1V (G-V)(A1V) = 0.005 ; * 49 Cet PM* A1V (G-V)(A1V) = 0.008 ; * alf Lac PM* A1V (G-V)(A1V) = 0.012 ; * 35 Vul * A1VmA3 (G-V)(A1V) = 0.015 ; fit for A dwarfs from Kervella19 corrected for E(B-V), eval for (V-Ks)=0.090 (G-V)(A1V) = 0.024 ; * tet Cap PM* A1V => adopt (G-V)(A1V) = 0.01 [updated 4/8/2022] (U-B)(A1V) = 0.01 ; Fitzgerald70 (U-B)(A1V) = 0.030 ; HIP d<75pc S/N>8 A1V N=34 (Mermilliod91 photometry) (U-B)(A1V) = 0.05 ; JohnsonMorgan53 (V-I)(A1V) = 0.015 ; Bessell79 (A1V) = 0.071 (+-0.016 sem, +-0.023 stdev; N=4) (A1V) = 0.081 (+-0.011 sem, +-0.033 stdev); HIP d<75pc S/N>8 (N=12) (R-I)(A1V) = 0.008 ; Bessell79 (g-r)(A1V) = -0.080 ; Jordi06 (V-R)=>(g-r) for V-R=0.016 (g-r)(A1V) = -0.213 ; Bilir05 (B-V)=>(g-r) for B-V=0.035 (g-r)(A1V) = -0.24 ; Covey07 interp A0V-A2V => adopt (g-r)(A1V) = -0.21 [updated 10/10/2020] Teff(A1V) = 9500 K ; Bessell79 Teff(A1V) = 9500 K ; GrayCorbally09 Teff(A1V) = 9480 K ; GrayCorbally94 Teff(A1V) = 9478 K ; pri. stan. HD 10939 (median Teff) Teff(A1V) = 9397 K ; Zorec12 median Teff(A1V) = 9320 K ; ter. stan. HD 74956/del Vel (median Teff) Teff(A1V) = 9296 K ; sec. stan. HD 9132/48 Cet (median Teff) Teff(A1V) = 9240 K ; ter. stan. HD 21447 Teff(A1V) = 9230 K ; Schmidt-Kaler82 Teff(A1V) = 9172 K ; EEM N=192 Teffs Teff(A1V) = 9150 K ; Theodossiou90 Teff(A1V) = 9026 K ; mean photometric Teff Teff(A1V) = 8938 K ; Boyajian12 => adopt Teff(A1V) = 9300 K (logT = 3.968) [updated 10/18/2019] [EEM 12/2/2012: Teffs for standards and median Teffs for A1Vs support median Teff for A1V in regime 9100-9250K, but not as high as GrayCorbally09's value (9500K) or Boyajian12's value (8938K).] BCv(A1V) = -0.191 mag ; Flower96(Teff=9300K, set so BCv(5772K)=-0.085) BCv(A1V) = -0.151 mag ; Code76(Teff=9300K, set so BCv(5772K)=-0.085) BCv(A1V) = -0.146 mag ; Balona94(Teff=9300K, set so BCv(5772K)=-0.085 BCv(A1V) = -0.138 mag ; Bessell98(ATLAS,logg=4.0,Teff=9300K, set so BCv(5772K)=-0.085 BCv(A1V) = -0.10 mag ; Schmidt-Kaler82 (BCv=-0.23 + 0.13 offset) BCv(A1V) = -0.105 mag ; Bertone04(ATLAS,Teff=9300K, set so BCv(5772K)=-0.085 => adopt BCv(A1V) = -0.14 [updated 9/16/2019, adjusted so that BCv(5772K)=-0.085] Mv(A1V) = 1.6 mag ; GrayCorbally09 Mv(A1V) = 1.52 mag ; exemplar HD 31647 = ome Aur (~40 Myr-old Columba member) Mv(A1V) = 1.38 mag ; SIMBAD d<60pc trend for SpT=A1V Mv(A1V) = 1.31 mag ; d<60 pc SIMBAD A1V N=12 Mv(A1V) = 1.306 +-0.123(sem),+-0.518(st.dev.); EEM N=34 A1V HIP d<75pc Mv(A1V) = 1.31 mag ; median Mv for A6V calc using Kervella19 HIP & Gaia DR2 (d<100pc) Mv(A1V) = 1.30 mag ; Wright05(B-V=0.035) Mv(A1V) = 1.26 mag ; B/A/F dwarf sequence for B-V=0.035 Mv(A1V) = 1.25 mag ; EEM trend logT vs Rad for A1V Mv(A1V) = 1.21 mag ; d<60pc Mv(B-V=0.04) Mv(A1V) = 1.16 mag ; linear B-V vs. Mv fit to d<50pc Gray01/03/06 dwarfs for B-V=0.035) Mv(A1V) = 1.0 mag ; Schmidt-Kaler82 Mv(A1V) = 0.84 mag ; Wegner07 => adopt Mv(A1V) = 1.16 mag [updated 9/26/2020] => adopt M_G(A1V) = 1.16 mag [updated 12/10/2020] (Mv=1.16, G-V=0.00) => adopt M_Ks(A1V) = 1.07 mag [updated 12/30/2020] (Mv=1.16, V-Ks=0.090) logL(A1V) = 1.488 dex ; Mv=1.16 + BCv=-0.14 => Mbol = 1.020 logL(A1V) = 1.497 dex ; logL/Teff trend for O7V-A2V dwarf EBs (Torres10; Teff=9300K) logL(A1V) = 1.69 dex ; sec. stan. 48 Cet (Zorec12) logL(A1V) = 1.77 dex ; Zorec12 median => adopt logL(A1V) = 1.488 dex [updated 9/26/2020] => adopt Mbol(A1V) = 1.020 mag [updated 9/26/2020] Mass(A1V) = 2.53 Msun ; Zorec12 median Mass(A1V) = 2.43 Msun ; sec. stan. 48 Cet (Zorec12) Mass(A1V) = 2.397+-0.025 Msun ; Eclipsing binary V396 Cas A (Torres10) Mass(A1V) = 2.27 Msun ; non-standard Castor A (Torres02;Teff=9400K) Mass(A1V) = 2.24 Msun ; EEM Teff vs. Mass fit for binaries (Teff=9300K) Mass(A1V) = 2.184+-0.037 Msun ; Eclipsing binary V1647 Sgr A (Torres10) Mass(A1V) = 2.16 Msun ; EEM Mv vs. Mass fit for binaries (Mv=1.34) Mass(A1V) = 2.16 Msun ; EEM logL vs. Mass fit for binaries (logL=1.452) Mass(A1V) = 2.15 Msun ; Ekers18 ML calibration for logL=1.452 Mass(A1V) = 2.097+-0.022 Msun ; Eclipsing binary VV Pyx A (Torres10) Mass(A1V) = 2.095+-0.019 Msun ; Eclipsing binary VV Pyx B (Torres10) Mass(A1V) = 1.967+-0.033 Msun ; Eclipsing binary V1647 Sgr B (Torres10) => adopt Mass(A1V) = 2.17 Msun [updated 12/29/2019] Rad(A1V) = 2.1364 Rsun ; logL=1.488, Teff=9300K Rad(A1V) = 2.040 Rsun ; logL=1.448, Teff=9300K => adopt Rad(A1V) = 2.136 Rsun [updated 9/26/2020] # No Standards Morgan65, MK73, MK78, Garrison79, Keenan85, & GrayAtlas do not list A1V standards. Skiff08 did not flag any stars as A1V standards. # Primary Standards HD 10939 = HR 520 A2V: Cuchiaro78,Cucchiaro80 *A1Va: Gray87(stan),Houk75(A1V) A0: Cannon The only modern classifications (Gray & Houk) both agree on A1 dwarf. vanLeeuwen07 parallax: 16.12+-0.17 mas, hence it is likely within the Local Bubble and negligible reddened. V=5.04 (HIP), B-V=0.035+-0.006 (Mermilliod91), B-V=0.031+-0.003 (HIP), U-B=0.059 (Mermilliod91), V-I=0.05+-0.00 (HIP), H = 5.026+0.027 (2MASS), Ks = 4.964 +-0.027 (2MASS), V-H = 0.014, V-Ks = 0.076. Teffs: 9063K(B-V=>Bessell98), 9084K(V-Ks=>vanBelle09), 9110K+-282K(Paunzen06,Stassun18), 9222K(GaiaDR2), 9478K(Ballering13), 9599K(David15), 9692K(Philip80), 9750K(Chen14), 10090K(Sokolov95) => = 9478K. # Secondary Standard HD 9132 = 48 Cet *A1Va: Gray87(stan) A1V: Jaschek64(both),Bond71,Jaschek78(Buscombe62),Hoffleit91 A1IV: Abt95 A0V: Houk88,Cannon(A0) Mostly agreement on A1V type. dMv=-0.42, so slightly above MS. HIP: B-V=0.028+-0.003, V-I=0.04+-0.00, V = 5.11. Mermilliod91: V=5.117+-0.007, B-V=0.023+-0.006, U-B=0.071+-0.023. 2MASS: J is poor, H = 5.026+-0.026, Ks=4.963+-0.020. V-Ks = 5.117-4.963 = 0.154. logL=1.6913+-0.0228(Zorec12). Mass=2.43+-0.03 Msun(Zorec12). age = 667+-45 Myr(Zorec12). vsini=32 km/s(Zorec12). logg=4.08+-0.08(Allende-Prieto99). Teffs: 9177K(GaiaDR2), 9200K(Grenier99), 9296K(B-Vo=>Bessell98, for logg=4.1), 9333K(Zorec12,Stassun18), 9552K(David15) => = 9296K. # Tertiary Standard HD 74956 = del Vel = HR 3485 *A1Va(n): Gray06 A1Va: Gray87,Garrison96(for "AB") A1V: Levato72,Jaschek78 A0V: Houk75(overexp,from Garrison) A2V: Cucchiaro80 Garrison96 gives A1Va for AB combined (0.74" separation, deltaV ~ 3.6 mag). Not a Gray87 A1Va standard. HIP: V=1.93, B-V = 0.043+-0.006, V-I = 0.05+-0.02. Mermilliod91 photometry for unresolved pair: V=1.956+-0.008, B-V=0.039+-0.003, U-B=0.064+-0.016. 2MASS photometry is poor in all bands. Teffs: 9021K(Gray06), 9200K(Grenier99), 9290K(Zorec12), 9298K(Stassun18), 9320K(Sokolov95), 9450K(Eker15), 9477K(David15), 9500K(Su08), 9830K(Eker15#2) => = 9320K. logg=3.66(Allende-Prieto99), 3.79(Gray06). [M/H]=-0.33(Gray06). Mass=2.51Msun(Allende-Prieto99) HD 21447 = HR 1046 A0V: Rydstrom78 *A1V: JM53,Jaschek64(most),GrayGarrison87(A1Va),Abt95(A1Vn),Zorec09(BCDtype) A2V: Cowley69,Cannon(A2) A2.5V: Levato78 A3V: Roman49 Adopt GrayGarrison87's "A1Va". Mostly agreement on A1V, but some A2 and A3 types. plx = 16.8324+-0.1689mas(GaiaDR2). Companion 14" away, 5mag fainter. V=5.09(HIP), V=5.096+-0.012(Mermilliod91), B-V=0.022+-0.015(HIP), B-V=0.041+-0.004(Mermilliod91), U-B=0.036+-0.003(Mermilliod91), V-I=0.06+-0.03(HIP). Teffs: 9078+-126K(Zorec12,Stassun18), 9232K(GaiaDR2), 9240+-300K(Zorec09), 9335K(King03), 10049K(David15), => = 9240K. # Deprecated Standards Alf CMa = Sirius kB9.5hA0mA1s: Abt95 A0: Cannon18(stan) kA0hA0VmA1: Levato78 A0VamA1: Houk88(Garrison) *A0mA1Va: GrayGarrison87,Gray03 A1V: MK43,Cowley67,Cowley69,Levato72,Cucchiaro80,Bidelman85(A1) A2IV: Adams35 Brightest star, with WD companion. HD 60179 = alf Gem A = Castor A A1V: MK43, Cowley69(stan) A and B are bright and within 3". Four stars within 3". Haven't listed all types. Junk. HD 47015 = Gam Gem = HR 2421 A1V: MK43 A0IV: JM53,Jaschek64(most) *A1.5IV+: Gray03 A2IV: Abt95 A1IVs: GrayGarrison87 Temperature type switched from MK43 to JM53. I haven't list all types, but clearly not a good standard. HD 198001 = eps Aqr = 2 Aqr = HR 7950 A1V: JM53,Jaschek64(all) *A1III: Houk99(Garrison),GrayGarrison87(A1III-) A1.5V: Abt95 A2V: Cowley69,Levato69 A0: Cannon B9.5V: Levenhagen06 Garrison & Gray now consider this a giant. HD 45320 = HR 2324 *A1Vann: Gray87(stan) A1V: Houk99 A2Vnp: Abt95 A3Vn: Cowley69 A7: Bertaud67 A7IIIp: Jaschek64(deVacouleur57) A0: Cannon vsini~300 km/s. Abt95 comments MgII 4481A weak. Only Gray and Houk have called it A1V. HD 18331 = HR 875 A1V: JM53,Abt95(A1Vn),Paunzen01 A3Vn: Roman49(A3V),Cowley69,Levato78 A3/4IVb: Barry70 Not the strongest pedigree. Tough to take the A1V classification seriously when 4 other classifers find A3 or A4ish. HD 95418 = bet UMa = HR 4925 A0mA1IV-V: Gray89 A1V: MK43, Cowley69(stan), Levato78(A1Vs), Loden83(A1VSi) A1IV: Abt95 *A1IVps(SrII): Gray03 A2III: Adams35 A2.5: 1941ApJ....94..215S (B-V[HIP]=0.033+-0.003) ~0.88 mag above MS HD 140159 = iot Ser = HR 5842 A1V: JM53,Osawa59,Jaschek64(all),Cowley69(stan),Houk(stan),Abt95(A1Vp) *B9Vn+A1V: Abt81 A0.5V: Palmer68 Close pair: 0.2", and apparently similar but not identical. Abt95 says MgII 4481A weak. HD 170073 = 39 Dra = b Dra = HR 6923 A1V: JM53,Jaschek64(all),Palmer68 *A2V: GrayGarrison87(A2Va),Abt95 A3V: Cowley69 4" binary: A0V+F6V (Edwards76), A1V+F5V (Lutz77). Johnson-Morgan type differs from later Gray/Garrison/Abt/Cowley types. HD 193702 = HR 7784 *A1V: JM53,Slettebak61,Cowley69(stan),Christy69,Abt95,Paunzen01 A0IV: Barbier62,Abt81,Cannon(A0) A0V: Levato78 A3V: Barry70 A2V: Osawa59 Jaschek64 lists 4 different types in A0-A3 range from 6 references. Tight triple! CCDM lists *3* components within 3" of each other. A tight 0.3" binary with a 3.3" companion further out. # Exemplar 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. Gagne18 lists it as member of Columba ~40 Myr association. GaiaEDR3: plx(A)=20.2399+-0.1077mas(GaiaEDR3), plx(B)= 20.4394+-0.0228mas. V(AB)= 4.952+-0.022(Mermilliod91), B-V(AB)=0.040+-0.010(Mermilliod91), U-B(AB)=0.025+-0.015(Mermilliod91). HIP/TYC: Bt(A)= 5.014+-0.004, Vt(A)= 4.991+-0.004 => converted via Mamajek06 => V=4.989+-0.004, B-V=0.015+-0.005. Mv(A) = 1.520+-0.012(HIP/TYC,GaiaEDR3). # Other Stars Zet UMa A A1Va: Garrison96 Del Her A1Vann: Garrison96 HD 111397 = HR 4865 = 29 Com (V=5.7) *A1V: Cowley69,Loden83,Abt95,Paunzen01 A2V: Osawa59,Levato78 RECONS shows Sirius (J0645-1642) as the nearest A1V star.