M0III only included "pure" M0III standards from Keenan89 so far Probably the best southernly accessible standard is ups Gem (J0735+2653) MK43 standards: bet And - M0III JM53 standards: bet And - M0III ups Gem - M0III lam Dra - M0III Keenan63 standards: mu UMa - M0III 50 Her - M0IIIa 75 Leo - M0IIIb bet And - M0III 106 Her - M0III Deutsch69 standards: bet And (=HD 6860) - M0III ups Gem (=HD 60522) - M0III MK73 dagger standard: bet And (=HR 337) - M0IIIa mu UMa (=HR 4069) - M0III H & K em Houk standard: ups Gem (=HR 2905 = HD 60522) - M0III [from MK73] Keenan89 standards: gam Phe (=HD 9053) - M0III ups Cet (=HD 12274) - M0III ups Aur (=HD 38944) - M0III ups Gem (=HD 60522) - M0III mu UMa (=HD 89758) - M0III 61 Leo (=HD 95578) - M0III 75 Leo (=HD 98118) - M0III HD 213893 - M0IIIb GrayCorbally10 standard: ups Aur (=HD 38944) - M0III (J-H)(M0III) = 0.756 (+-0.031 sem, +-0.047 stdev) ; N=4 M0III from Skiff compendium w/i 15deg of NGP, 2MASS photometry AAA flags => adopt (J-H)(M0III) = 0.76 (H-Ks)(M0III) = 0.215 (+-0.007 sem, +-0.010 stdev) ; N=4 M0III from Skiff compendium w/i 15deg of NGP, 2MASS photometry AAA flags => adopt (H-Ks)(M0III) = 0.22 [smoothed from among K/M giants] # Primary standard ups Aur = HD 38944 M0III: Keenan89,GrayCorbally10 ups Gem = 69 Gem = HR 2905 = HD 60522 (J0736+2654; V=4.06) M0III: Adams26,JM53,Merrill62,Jaschek64(most),Deutsch69(stan),MK73,Houk(stan),Keenan89(stan),Keenan99 M0III-IIIb: Keenan80 K5III: Roman52 K5: Cannon Adopt "M0III" from Keenan99, Keenan89, MK73, JM53. Both Houk88 and Keenan99 err in calling this star "\nu Gem" and cross-IDing it with "HR 2905" and "HD 60522", however "\nu Gem" is a B-type star. SIMBAD matches HR 2905 and HD 60522 to "\upsilon Gem" (as Keenan89 correctly did). Keenan's types never wavered from "M0" and giant, so it would appear to be a good standard. plx = 13.57+-0.87 mas (Hipparcos 1997), so probably unreddened. mu UMa = HR 4069 = HD 89758 (J1022+4129; V=3.03) M0III H & K em: MK73(dagger) M0III: Keenan80,Keenan89(stan) K5III: Adams35 Adopt "M0III" from Keenan89 and MK73. # Secondary standard 75 Leo = HR 4371 = HD 98118 (J1117+0200; V=5.2) M0III: Adams26,Roman55,Keenan89(stan) M0III+: Keenan53 M0IIIb: Keenan63 M0.5II CN-STG: Buscombe95(primary reference unknown) M0.5II CN: Buscombe99(primary reference unknown) K5III: Houk99 K5: Cannon Jaschek78 quotes the Keenan53 type as "M0.III COMP", however it is only listed as "M0III+" in the Keenan53 paper, and there are no further notes on it. Keenan varied the luminosity type slightly a few times, but never the temperature type "M0". Adopt "M0III" from Keenan89. # Variant bet And = HR 337 = HD 6860 (J0109+3537; V=2.05) M0+IIIa: Keenan89,Keenan99 M0IIIa: MK73(dagger) M0III: Adams26,MK43,Keenan63,Jaschek64(all),Deutsch69(stan) M1IIIa: Abt85 M1: Pedoussaut62 M0.5III: Bidelman85 Adopt "M0+IIIa" from Keenan89 and Keenan99. gam Phe = HD 9053 = HR 429 M0III: Keenan89(stan) All 6 classifications before Keenan89 were K4/5/6. # Weak standard gam Eri = HD 25025 (J0358-1330; V=3.0) M0III-IIIb: Keenan89 M0III: Adams26,Buscombe62,Keenan99 M1III: Keenan63 M1IIIb: Abt08 M1IIIBCA-1,CR-1: Houk88 Keenan quoted three different classifications for this star. Adopt "M0III" from Keenan99. Could use as a secondary standard, however I'd prefer to understand the meaning of the letters in the Houk88 classification before using it. 50 Her = HR 6258 = HD 152173 (J1650+2948; V=5.7) M0IIIa: Keenan63(stan) M1+IIIa: Buscombe99(unknown primary reference) M1III: Adams26 M4: Lee47 K5: Cannon Weak pedigree for use as a standard. Adopt "M0IIIa" from Keenan63. 106 Her = HR 6868 = HD 168720 (J1820+2157; V=4.96) M1IIIb: MK73(dagger) M1III: Deutsch69(stan),Keenan80,Keenan89(non-standard) M3: Lee47 M0III: Adams26,Keenan63(stan) K5: Cannon Three subtle changes by Keenan to the type over the years. Adopt "M1III" from Keenan89.