G5IV

Garrison94 lists Mu Her (HR 6623 = HD 161797) as the G5IV anchor standard.

JM53 and MK73 list Mu Her (= HR 6623 = HD 161797) as the G5IV
standard.

Keenan89 lists HD 161797 (Mu Her) and HD 188376 as G5IV standards.

Houk88 adopts mu Her (HR 6623, HD 161797) as their G5IV standard, and
cites MK73.

GrayNstars lists ome Sgr (HD 188376) as their G5IV CTIO standard and Mu Her as a 
G5IV DSO standard. 

# Primary Standards
HD 161797 = HR 6623 = Mu Her (J1636+4244, V=3.4)
  G5IV: MK43,Roman55(lines weak),Keenan89,Gray01,GrayNstars,Cannon(G5),Jaschek64(most)
  Has a 35" companion which itself is binary (BC: M4V,V=9.8)
  B-V=0.750, revised HIP => Mv=3.82, 1.57 mag above MS.

HD 188376 = HR 7597 = ome Sgr = HIP 98066 (J1955-2617,V=4.7)
  G5IV: Keenan89
  G3/5III: Houk82
  G5: Cannon
  Houk82 notes; "HR 7597; *OMEGA SGR; OR POSSIBLY COMPOSITE G6/8 III + EARLY G"
  B-V=0.757 (Mermilliod91)