A5IV


Houk88 lists tau Peg (HR 8880, HD 220061) as a secondary standard
(A5IV), and cites Houk75.

GrayNstars lists Bet Tri as their A5IV Steward Obs. and DSO standard.

# No Standard
JM53, MK73, Cowley74 do not list A5IV standards

# Primary Standard
HD 13161 = Bet Tri
  A5IV: Gray01
  A5III: Jaschek64(all),JM53(SB:)
  A5: Cannon
  *All* agree on A5 subtype (indeed it is the HD standard, Cannon 1918).
  B-V = 0.140, HIP2 => Mv=0.05, 1.71 mag above MS. It is situated right
  at the end of the main sequence on the HR diagram. 

# Weak Standards
HD 220061 = Tau Peg
  A5IV: Slettebak55,Jaschek64(both),Jaschek78(Cowley69)
  A8VkA5mA5: Gray01(MgII 4481A weak)
  A5Vp lam Boo: Abt95
  A5V: Ortega83,GrayGarrison89,Andrillat95,Paunzen01
  A5: Cannon
  A4: Olson69
  B-V=0.180, HIP2 => Mv=1.10, 0.83 mag above MS. 
  Lam Boo star. Mostly considered A5, either V or IV.