M2III

only "pure" M2III standards from Keenan89 listed so far

Best southernly accessible standard M2III is HD 1879 

MK43 standards:	         chi Peg - M2III
			 bet Peg - M2II-III
JM53 standards:          chi Peg - M2III
		         alf Cet - M2III
		         pi Leo - M2III
		         83 UMa - M2III
Keenan63 standards:	 74 Vir - M2+III
			 bet Peg - M2+IIb-IIIa
			 pi Leo - M2III
			 83 UMa - M2IIIab
			 alf Cet - M2III (4226 weak)
			 chi Peg - M2III
Abt68 standard:		 del Oph - M2III
Deutsch69 standard:	 chi Peg (=HD 1013) - M2III
			 bet Peg (=HD 217906) M2-3II-III (variable)
MK73 dagger standard:    8 And (=HR 8860) - M2III
		         83 UMa (=HR 5154) - M2IIIab
		         chi Per (=HR 45) - M2+III
     	    	         pi Leo (=HR 3950) - M2-IIIab
Houk sec. standard:	 HR 4278 (=HD 5129) - M2III [from Roman55]
Houk standard:		 pi Leo (=HR 3950) - M2III [adopted from M2-IIIab from MK73]
Turnshek85 standard:     chi Peg (HD 1013) - M2+III
Keenan89 standard:       HD 1879 - M2III
		         83 UMa (=HD 119228) - M2III
		         87 Vir (=HD 120052) - M2III
		         HD 123934 - M2IIIa
			 HD 222670 - M2III
Kirkpatrick91 standard:  83 UMa - M2III [from KeenanMcNeil76]
			 chi Peg - M2III [from KeenanMcNeil76]
GrayAtlas standard:	 chi Peg - M2III
GrayCorbally10 standard: chi Peg - M2+III

(J-H)(M2III) = 0.828 (+-0.029 sem, +-0.050 stdev) ; N=3 M2III from Skiff compendium w/i 15deg of NGP, 2MASS photometry AAA flags
(J-H)(M2III) = 0.829 ; smoothed relation from giants in Skiff compendium w/i 15 deg of NGP, 2MASS photometry AAA flags
=> adopt (J-H)(M2III)  = 0.829

(H-Ks)(M2III) = 0.263 (+-0.009 sem, +-0.015 stdev) ; N=3 M2III from Skiff compendium w/i 15deg of NGP, 2MASS photometry AAA flags
=> adopt (H-Ks)(M1III) = 0.26 [smoothed among M giants]

# Primary standard
 
83 UMa = HR 5154 = HD 119228 (J1340+5440; V=4.66)
   M2IIIab: Keenan63,MK73(dagger)
   M2III: Adams26,JM53,Keenan89
   M2: Pedoussaut61

   Good agreement on types. Adopt "M2III" from Keenan89.

# Secondary standard

HD 1879 (J0023-1556; V=6.5)
   M2III: Roman55(Jaschek78),Crampton73,Keenan89
   M2:III: McNeil86(also cites M2III: by Keenan)
   M3III: Adams26
   M0III: Houk88

   Adopt "M2III" from Keenan89.

# Variants

8 And = HR 8860 = HD 219734 (2317+4900; V=4.86)
   M2III: Adams26,MK73(dagger),Abt85
   M2.5III Ba0.5: Keenan89
   M2: Pedoussaut61

   Adopt "M2.5III Ba0.5" from Keenan89. 

pi Leo = HR 3950 = HD 86663 (V=4.7)
   M2-IIIab: MK73(dagger)
   M2-III: Keenan89
   M2III: Adams26,JM53,Keenan63(stan),Houk(stan)
   M0: Lee47

   Adopt "M2-III" from Keenan89. 


# Weak standard

chi Peg = HR 45 = HD 1013 (J0218+5730; V=6.0)
    M2+III: MK73(dagger),Turnshek85(stan),Keenan89,GrayCorbally10
    M2III: Adams35,MK43,Keenan63
    M0+III: Keenan99
    M1III: Adams26,Moore50

    Inexplicably, Keenan shifted this long-time ~M2 giant to "M0+III"
    in 1999.  I would avoid using this star as a standard given that
    Keenan changed the the temperature type three times: "M2", "M2+",
    "M0+".

alf Cet = HR 911 = HD 18884 (J0257+0342; V=2.53)
    M1.5III: MK73(dagger)
    M1.5IIIa: Keenan89(stan),Keenan99
    M2III(4226 weak): Keenan63

    Keenan changed the type slightly three times, but not between 1989
    and 1999 works. Adopt "M1.5IIIa" from Keenan89 and Keenan99.

del Oph = HR 6056 = HD 146051 (J1614-0341; V=2.75)
    M0.5III: Keenan63,Deutsch69(stan),MK73(dagger),Keenan89,Kirkpatrick91
    M0: Pedoussaut62
    M0III: Adams25
    M2III: Abt68(stan)

    Adopt "M0.5III" from Keenan89 and MK73. Was considered "M2III"
    standard in Abt68 atlas.