G2IV phi Vir appears to be the best G2IV standard. JM53, MK73, and Houk88 do not list a G2IV standard. MK43 standard: mu Cnc - G2IV lam Aur - G2IV-V Turnshek85 standard: phi Vir (=HR 5409 = HD 126868) - G2IV Keenan89 standards: phi Vir (=HR 5409 = HD 126868) - G2IV kap Del (=HD 196755) - G2IV 42 Cap (=HD 206301) - G2IV HD 217014 - G2IV HD 31966 - G2IV-V Fe-1 GrayNstars standards: phi Vir (=HR 5409 = HD 126868) - G2IV kap Del (=HR 7896) - G2IV Among Gray03 and Gray06 stars within 40 pc: B-V(G2IV) = 0.652 (+-0.016 sem, +-0.027 stdev; N=3) V-I(G2IV) = 0.713 (+-0.015 sem, +-0.025 stdev; N=3) (B-V)(G2IV) = 0.672 ; ter. stan. 42 Cap = HD 206301 (B-V)(G2IV) = 0.689 ; pri. stan. phi Vir (B-V)(G2IV) = 0.690 ; poly fit to FGK subgiant standards & exemplars (B-V)(G2IV) = 0.702 ; sec. stan. kap Del => (B-V)(G2IV) = 0.69 [updated 1/28/2022] V-I(G2IV) = 0.73 ; pri. stan. phi Vir Teff(G2IV) = 5707 K ; deprecated stan. 42 Cap Teff(G2IV) = 5661 K ; sec. stan. kap Vel (see below) Teff(G2IV) = 5589 K ; pri. stan. phi Vir (see below) => adopt Teff(G2IV) = 5620 K [last updated 7/15/2017] Mv(G2IV) = 1.987 ; pri. stan. G2IV *_phi_Vir_ plx=26.88 mas, Vmag=4.840 Mv(G2IV) = 2.39 ; ter. stan. 42 Cap = HD 206301 plx=27.86 mas, Vmag=5.18 Mv(G2IV) = 2.68 ; sec. stan. kap Del = HD 196755 Mv(G2IV) = 3.0 ; GrayCorbally09 Mv(G2IV) = 3.01 ; quadratic trend G0IV-K2IV standards+exemplars (for G2IV) Mv(G2IV) = 3.235 ; G2IV+G2IV HD_202582__ plx=23.39 mas, Vmag=6.39 Mv(G2IV) = 3.68 ; HD_30562 => adopt Mv(G2IV) = 3.01 [updated 1/28/2022] # Primary Standards phi Vir = HD 126868 = HR 5409 (J1428-0213, V=4.8) *G2IV: Keenan80,Turnshek85(stan),Keenan89,Gray01,GrayNStars G2III: Jaschek64(most) G2IIIb: Abt81 G2III+G4V: Edwards76 G3V: Houk99 G0:III:: Bouw81 F9IV: Eggen52 K0: Cannon 5" pair (companion is V=9.9 K0V star according to Wilson52). In Hertzsprung gap. F9-K0 in the literature, but most recent literature agrees on "G2". Revised HIP data leads to Mv=2.01, 3.05 mag above MS. B-V=0.689(Tycho=>Johnson), B-V(AB)=0.693+-0.013(HIP), B-V=0.74(Johnson66), U-B=0.21(Johnson66), U-B=0.204+-0.004(Mermilliod91), V=4.835+-0.003(Tycho=>Johnson), V-I=0.73+-0.02(HIP), plx=24.15mas(i.e. nearby and unreddened). Companion is 5 magnitudes fainter than A, hence unresolved colors are largely unaffected by B. PASTEL values: = 5589K (N=3), <[Fe/H]> = -0.04 (N=2). # Secondary Standards kap Del = HD 196755 = HR 7896 *G2IV: Adams35(G2IV/V),Harlan74,Keenan89(stan),1957ArA.....2...55O G5IV: Jaschek64(most),Roman55,Roman52 G5: Cannon G4: Bidelman85 G3V: Abt85 G0IV-V: Lutz77 B-V=0.702. revised HIP => Mv=2.68, 2.4 mag above MS. Star has oscillated between G0 and G5. PASTEL values: =5661K(N=7), <[Fe/H]>=0.00(N=6). # Tertiary Standard 42 Cap = HD 206301 = HR 8283 = HIP 107095 = BY Cap (RS CVn variable?) *G2IV: Keenan89(stan),Jaschek78(Roman52(lines strong)) G2V: Gray89 G1IV: Gray06 G1V: Adams35 G5: Cannon SIMBAD says its a RS CVn. V=5.16(HIP), B-V=0.672+-0.003(HIP), V-Ic=0.73+-0.04(HIP). plx=27.8625+-0.1503mas(GaiaEDR3) => Mv=2.39. PASTEL 2 Teffs: 5682+-70K(Chen00), 5732+-80K(Casagrande11) => 5707K. logg=3.98+-0.10(Chen00), [Fe/H]=-0.04+-0.10(Chen00). vsini = 4.8 km/s (Glebocki05). # Deprecated Standard HD 217014 = 51 Peg = HR 8729. *G2V: Bidelman85,Gray01,Gray06(G2V+),1957ArA.....2...55O G2IV: Keenan89(stan) G2.5IVa: Keenan80 G5V: Cowley79,Jaschek78(Harlan70) G3V: Gray03 G4V: Stebbins57 G0: Cannon Famous metal-rich planet host with hot Jupiter discovered in 1995. B-V=0.666. Revised HIP data => Mv=4.48, so 0.41 mag above MS. Temperature types are in G0-G5 range. Clearly a dwarf, only considered subgiant by Keenan89. Do not recommend as a standard. Basically a metal-rich G2V. PASTEL median values: = 5773K (N=33), <[Fe/H]> = 0.19 (N=25). # Other Stars HR 8531 Aa = HD 212330 = GJ 857 = HIP 110649 F9V: Malaroda75 G0: 1932PLicO..18....1M *G2IV-V: Gray06 G3IV: Houk75V: G8V: 1966ArA.....3..501L Only listed here as it is one of the oldest thin disk stars in the solar neighborhood, as pointed out by Fuhrmann17. plx=48.8901+-0.1153 mas. PASTEL: =5653K(N=11), =4.14(N=8), <[Fe/H]>=-0.02(N=8). Age=7.9Gyr(Bryden06), 8.08Gyr(Kospal09), 7.90Gyr(Gaspar13), 7.0(6.2-8.0)Gyr(Valenti05), 8.08(7.72-8.48)Gyr(Takeda07), 7.90(5.3-8.59)Gyr(Casagrande11), 7.90(6.48-8.75)Gyr(Casagrande11#2), 7.91Gyr(Vican12), 8.4(7.8-9.0)Gyr(Holmberg09). Fuhrmann17: "70 Vir– along with HR 7845A and HR8531Aa – is one of the three Population I subgiants of the survey, which provide the solid 8 Gyr formation time-scale of this population." HD 74811 G2IV: Heard56,Harlan69