A3IV JM53, MK73, and Houk88 do not list A3IV standards MK43 standard: del Her - A3:IV:n GrayGarrison89 list HR 4293 as their low-vsini A3IV standard, and bet Eri as their high-vsiniA3IV standard. GrayNstars list Bet Eri (HD 33111 = HR 1666) as their A3IV CTIO, DSO, and Steward Obs. standard. JM53 lists del Her as a non-standard A3IV star. (B-V)(A3IV) = 0.114 ; (B-V)(A3V)=0.09 plus trend seen for other IV stars (B-V)(A3IV) = 0.116 ; pri. stan. HD 95370 (B-V)(A3IV) = 0.131(+-0.021 sem,+-0.055 stdev) ; SIMBAD median A3IV d<100pc,V<6.5 (N=12) => adopt (B-V)(A3IV) = 0.12 [updated 2/3/2022] Mv(A3IV) = 1.04(+-0.21 sem, +-0.66 stdev) ; SIMBAD median A3IV d<100pc,V<6.5 (N=12) Mv(A3IV) = 0.7 ; GrayCorbally09 Mv(A3IV) = 0.47 ; pri. stan. HD 95370 # Primary Standard HD 95370 = HR 4293 (J1100-4213) *A3IV: GrayGarrison89(low-vsini stan.),Levato72 A3V: Houk78 A2IV: deVaucouleurs57,Jaschek64(all) A2: Cannon B-V=0.116+-0.005(HIP), V-I=0.13(HIP), V=4.37(HIP), Mv=0.47. # Secondary Standard HD 33111 = bet Eri = HR 1666 (J0507-0505, V=2.8) A3IV: Gray03 *A3IVn: GrayGarrison89(high-vsini stan.) A3III: JM53,Abt95,Levato72 A3V: Levato78,Palmer68 A2IV: Bouw81 Good agreement on "A3" temperature type. I adopt the GrayGarrison89 luminosity class, so "A3IVn" it is. # Deprecated Standard HD 156164 = del Her = HR 6410 A3IV: JM53(non-stan),Jaschek78,Jaschek64(all) A3:IV:n: MK43 A3Vn: Cowley69 A2Vn: Abt95 A1IVann: GrayGarrison87 *A1IVn: Gray03 A2: Cannon V=8 companion 11" away (G-dwarf). Not great agreement on subtype.