MM0.5 Kirkpatrick (in GrayCorbally09) call Gl 846 the primary M0.5V standard. Boeshaar76 standard: Gl 96 - M0.5 (Plate II & V standards) KeenanMcNeil76 standard: Gl 846 (=HD 209290) - M0.5V Keenan80 standard: Gl 4B (=HD 38B) - M0.5V Gl 846 (=HD 209290) - M0.5V Boeshaar85 standard: Gl 846 (=HD 209290) - M0.5V Keenan88 standard: Gl 172 (=HD 232979) - M0.5V Keenan89 standard: Gl 846 (=HD 209290) - M0.5V Gl 172 (=HD 232979) - M0.5V Kirkpatrick91 standards: Gl 846 (=HD 209290) - M0.5V (primary stan.) Gl 839 - M0.5V (secondary stan.) GJ 2155 - M0.5V (secondary stan.) Gl 761.2 - M0.5V (secondary stan.) Gl 720A - M0.5V (secondary stan.) Gl 767A - M0.5V (secondary stan.) Henry02 standard: Gl 846 (=HD 209290) - M0.5V GrayNstars standard: Gl 846 (=HD 209290) - M0.5V Kirkpatrick(GrayCorbally09) stan.: Gl 846 (=HD 209290) - M0.5V Skiff08 flags one stars as M0.5V MK standard: HD 232979 = GJ 172 (Keenan89). Joy74 M0.5V stars appear to be approximately M0V on the Kirkpatrick91 system. Kirkpatrick12 lists only 1 M0.5V stars within 8 pc: Lacaille 9352 = Gl 887, however most sources have it somewhat cooler. (B-V)(M0.5V) = 1.379 ; ter. stan. GJ 4B (B-V)(M0.5V) = 1.453 ; pri. stan. GJ 846 ([Fe/H] ~ 0.0) (B-V)(M0.5V) = 1.455 ; interp M0V-M1V V-Ks vs. B-V for V-Ks=3.84 (B-V)(M0.5V) = 1.461 ; deprecated stan. GJ 2155 = LHS 3947 (B-V)(M0.5V) = 1.469 ; median Koen10 d<25pc M0.5 (M0.5V) = 1.47 ; Fitzgerald70 (B-V)(M0.5V) = 1.497 ; sec. stan. GJ 96 ([Fe/H] ~ +0.14) => adopt (B-V)(M0.5V) = 1.455 [updated 3/2/2021] (V-I)(M0.5V) = 1.98 ; Hawley96 (M0.5V) = 3.11 (+-0.34 stdev) ; Lepine12 (V-Ks)(M0.5V)= 3.628 ; deprecated stan. GJ 2155 = LHS 3947 (V-Ks)(M0.5V)= 3.656 ; ter. stan. GJ 4B (V-Ks)(M0.5V)= 3.748 ; trend K/M dwarfs standards & exemplars (V-Ks)(M0.5V)= 3.838 ; pri. stan. GJ 846 (V-Ks)(M0.5V)= 3.846 ; sec. stan. GJ 96 (V-K)(M0.5V) = 3.9 ; Hawley96 => adopt (V-Ks)(M0.5V) = 3.84 [last updated 9/16/2017] => adopt (U-B)(M0.5V) = 1.184 => adopt (B-V)(M0.5V) = 1.441 (note disagreement with B-Vs above?) => adopt (Bt-Vt)(M0.5V)= 1.662 => adopt (V-Ic)(M0.5V) = 1.886 => adopt (V-Rc)(M0.5V) = 0.924 => adopt (Rc-Ic)(M0.5V)= 0.962 => adopt (V-J)(M0.5V) = 3.012 => adopt (V-H)(M0.5V) = 3.632 => adopt (H-Ks)(M0.5V) = 0.208 => adopt (J-H)(M0.5V) = 0.620 => adopt (V-Hp)(M0.5V) = -0.073 (G-J)(M0.5V) = 2.143 ; Bentley18/interp (G-Ks)(M0.5V) = 2.992 ; Bentley18/interp (Ks-W2)(M0.5V) = 0.160 ; Bentley18/interp (W1-W2)(M0.5V) = 0.035 ; Bentley18/interp (Ks-W1)(M0.5V) = 0.130 ; fit to Winters15 data for V-Ks=3.84 (Ks-W1)(M0.5V) = 0.125 ; Bentley18/interp (Ks-W1)(M0.5V) = 0.100 ; Best18 (Ks-W1)(M0.5V) = 0.078 ; Avenhaus12 for V-Ks=3.84 => adopt (Ks-W1)(M0.5V) = 0.125 [updated 12/28/2019] (Bp-Rp)(M0.5V) = 1.8050 ; HD_232979_ (Bp-Rp)(M0V) = 1.84 ; M0V mean (Bp-Rp)(M0.5V) = 1.8806 ; GJ_4B ter. stan. (Bp-Rp)(M0.5V) = 1.9714 ; GJ_846 pri. stan. (Bp-Rp)(M0.5V) = 1.9876 ; GJ_96 sec. stan. (Bp-Rp)(M0.5V) = 2.09 ; M1V mean => adopt (Bp-Rp)(M0.5V) = 1.97 [updated 7/10/2020] (G-Rp)(M0.5V) = 0.9063 ; HD_232979_ M0.5V (G-Rp)(M0.5V) = 0.9218 ; V*_AX_Mic M1V (G-Rp)(M0.5V) = 0.9363 ; GJ_4B ter. stan. (G-Rp)(M0.5V) = 0.9623 ; V*_SZ_UMa M1V (G-Rp)(M0.5V) = 0.9645 ; GJ_846 pri. stan. (G-Rp)(M0.5V) = 0.967 ; color trend M0V-M9V (G-Rp)(M0.5V) = 0.9695 ; GJ_96 sec. stan. (G-Rp)(M0.5V) = 0.9918 ; HD_199305 M1V (G-Rp)(M0.5V) = 1.0032 ; HD_42581 M1V (G-Rp)(M0.5V) = 1.0105 ; BD+11_2576 M1V (G-Rp)(M0.5V) = 1.0170 ; V*_BR_Psc M1V_Fe-1 (G-Rp)(M0.5V) = 1.0224 ; HD_165222 M1V => adopt (G-Rp)(M0.5V) = 0.97 [updated 11/18/2020] => adopt (Bp-G)(M0.5V) = 1.00 [updated 11/18/2020; Bp-Rp=1.97, G-Rp=0.97] (Bp-G)(M0.5V) = 0.9443 ; GJ_4B (Bp-G)(M0.5V) = 1.0068 ; GJ_846 (Bp-G)(M0.5V) = 1.0181 ; GJ_96 (G-V)(M0.5V) = -0.765 ; trend for SIMBAD d<20pc for V-Ks=3.84 (G-V)(M0.5V) = -0.760 ; trend Kervella19 d<25pc for V-Ks=3.84 (G-V)(M0.5V) = -0.758 ; polynomial fit to SIMBAD d<25pc M dwarfs (G-V)(M0.5V) = -0.7551 ; GJ_96 sec. stan. (G-V)(M0.5V) = -0.7437 ; GJ_846 pri. stan. (G-V)(M0.5V) = -0.709 ; GJ_4B ter. stan. => adopt (G-V)(M0.5V) = -0.76 [updated 11/1/2020] => adopt (G-Ks)(M0.5V) = 3.84 + -0.76 = 3.08 [updated 11/1/2020] (r-i)(M0.5V) = 0.633 (+-0.05 rms) ; West05 fit for (V-Ic)=1.886 (z-J)(M0.5V) = 1.312 ; poly fit to d<100pc GCNS for G-Ks=3.08 (rms=0.028) Teff(M0.5V) = 3646 +- 48 K ; Lepine12 Teff(M0.5V) = 3684 +- 9 K ; Boyajian12b (N=2) Teff(M0.5V) = 3734 K ; Morrell19 for stars w/i +-0.1 mag of M_Ks=5.36 Teff(M0.5V) = 3769 K ; smooth Teff(SpT) trend Teff(M0.5V) = 3770 K ; Rad=0.5459Rsun and Mann15 calib for M_Ks=5.36 & [Fe/H]=0.0 Teff(M0.5V) = 3785 K ; halfway between M0V(3870K) and M1V(3700K) Teff(M0.5V) = 3800 K ; Rajpurohit13 (N=1; LHS 3833a) Teff(M0.5V) = 3810 K ; empirical L-R relation for logL=-1.268 Teff(M0.5V) = 3810 K ; pri. stan. GJ 846 Teff(M0.5V) = 3840 K ; sec. stan. GJ 96 Teff(M0.5V) = 3913 K ; Passegger18 median Teff for CARMENES M0.5Vs(N=14) => adopt Teff(M0.5V) = 3770 K (logT = 3.576) [updated 4/9/2020] Mv(M0.5V) = 8.67 ; ter. stan. GJ 4B Mv(M0.5V) = 8.79 ; deprecated stan. GJ 2155 = LHS 3947 Mv(M0.5V) = 8.88 ; deprecated stan. GJ 720 A Mv(M0.5V) = 8.89 ; Kirkpatrick94 Mv(M0.5V) = 9.02 ; sec. stan. GJ 96 Mv(M0.5V) = 9.12 ; pri. stan. GJ 846 Mv(M0.5V) = 9.14 ; V-Ks=3.84 => fit to Reid CNS3 data Mv(M0.5V) = 9.20 ; M_G=8.44, G-V=-0.76 Mv(M0.5V) = 9.22 ; V-Ks=3.84 => fit to Jao16 Mv(M0.5V) = 9.28 ; V-Ks=3.84 => JohnsonApps09 polynomial Mv(M0.5V) = 9.30 ; V-Ks=3.84 => BurgasserMamajek17 polynomial => adopt Mv(M0.5V) = 9.20 mag [updated 11/3/2019] => adopt M_G(M0.5V) = 8.44 mag [updated 12/10/2020] (Mv=9.20, G-V=-0.76) => adopt M_Ks(M0.5V) = 5.36 mag [updated 11/3/2019] (Mv=9.20, V-Ks=3.84) M_G(M0.5V) = 7.42327 ; * alf Gem C M_G(M0.5V) = 7.44597 ; HD 28343 M_G(M0.5V) = 7.83935 ; BD+67 552 M_G(M0.5V) = 7.96687 ; HD 232979 M_G(M0.5V) = 7.9971 ; HD 38B M_G(M0.5V) = 8.100 ; deprecated stan. GJ 2155 = LHS 3947 M_G(M0.5V) = 8.11625 ; BD+63 869 M_G(M0.5V) = 8.14437 ; BD+45 2743 M_G(M0.5V) = 8.26373 ; GJ 3942 M_G(M0.5V) = 8.28467 ; HD 209290 M_G(M0.5V) = 8.28922 ; CD-36 6589 M_G(M0.5V) = 8.32299 ; HD 216133 M_G(M0.5V) = 8.44 ; Mv=9.20, G-V=-0.76 M_G(M0.5V) = 8.455 ; SIMBAD d<20pc trend for V-Ks=3.84 M_G(M0.5V) = 8.50518 ; BD+52 911 M_G(M0.5V) = 8.529 ; trend d<10pc SIMBAD M_G(M0.5V) = 8.58211 ; HD 331161A M_G(M0.5V) = 8.66183 ; HD 115404B M_G(M0.5V) = 8.82648 ; BD+19 3268 BC_Ks(M0.5V)= 2.551 ; Morrell19 trend for G-Ks=3.1 BC_Ks(M0.5V)= 2.549 ; Mann15 trend for V-J=3.012 BC_K(M0.5V) = 2.545 ; smoothed trend over M0V-M9V for M0.5V BC_K(M0.5V) = 2.544 ; interp M0V (3870K,BC_Ks=2.52) and M1V (3700K,BC_Ks=2.58) for T=3800K => adopt BC_Ks(M0.5V)= 2.55 [updated 11/3/2019] => adopt BCv(M0.5V) = -1.29 [updated 11/3/2019; BC_Ks=2.55, V-Ks=3.84] logL(M0.5V) = -1.272 ; Morrell19 trend for logL for M_Ks=5.36 logL(M0.5V) = -1.268 ; M_Ks=5.36, BC_Ks=2.55, Mbol=7.91 => adopt logL(M0.5V) = -1.268 [updated 11/3/2019] => adopt Mbol(M0.5V) = 7.910 [updated 11/3/2019] Rad(M0.5V) = 0.599+-0.021 Rsun ; sec. stan. GJ 96 (Yee17) Rad(M0.5V) = 0.560 Rsun ; Rabus19 trend for Teff=3810K Rad(M0.5V) = 0.546+-0.019 Rsun ; pri. stan. GJ 846 (Yee17) Rad(M0.5V) = 0.5459 Rsun ; Mann15 trend M_Ks=5.36, [Fe/H]=0.0 Rad(M0.5V) = 0.5445 Rsun ; logL=-1.268, Teff=3770K Rad(M0.5V) = 0.5092+-0.0013 Rsun ; Boyajian12b (N=2) => adopt Rad(M0.5V) = 0.544 Rsun [updated 4/9/2020] Mass(M0.5V) = 0.650 Msun ; Mv=9.20 => Torres10 binary calibration Mass(M0.5V) = 0.599 Msun ; M_Ks=5.36 => Benedict16 calibration Mass(M0.5V) = 0.581 Msun ; M_Ks=5.36 => Delfosse00 calibration Mass(M0.5V) = 0.569 Msun ; Mv=9.20 => Benedict16 calibration Mass(M0.5V) = 0.554 Msun ; logL=-1.266 => Eker15 calibration Mass(M0.5V) = 0.538 Msun ; M_Ks=5.36 => Mann18 calib. => adopt Mass(M0.5V) = 0.54 Msun [updated 11/3/2019] # Primary Standard GJ 846 = HD 209290 = BD+00_4810 *M0.5V: Boeshaar76,KeenanMcNeil76(stan),Keenan80,Cowley82,Boeshaar85(dM0.5),Keenan89,Kirkpatrick91(pri),Henry02,Kirkpatrick(GrayCorbally09)(pri),Lepine13,GrayNstars M0.6: Mann15 M0V: Vyssotsky52(M0Vp),Joy74,Bidelman85,Hawley97 M1: Gaidos14 M2/3V: Houk99(q=3) M3: Lee47 Ironically, the M0.5V subtype has a stronger pedigree standard star than the M0V type. Multiple metallicity estimates suggest that the star is near ~solar composition. V=9.17(HIP), B-V=1.453+-0.010(HIP), V-I=1.90+-0.01(HIP), J=6.196+-0.023(2MASS), H=5.562+-0.051(2MASS), Ks=5.322+-0.023(2MASS), V-Ks = 3.848. plx=97.61+-1.53mas(vanLeeuwen07) => Mv = 9.12. Teffs: 3580K(Alonso96), 3640K(Lepine13), 3715+-121K(Casagrande08), 3780K(Morales08), 3848+-60K(Mann15#1), 3875+-40K(Mann15#2), 3882+-97K(Gaidos14), 3898+-73K(Gaidos14) => = 3810K. [Fe/H]=0.03+-0.08(Gaido14), [Fe/H]=0.02+-0.08(Mann15), R=0.590+-0.059Rsun(Mann15), mass=0.60+-0.07Msun(Gaidos14), 0.571+-0.015Msun(Mann15). # Secondary Standards GJ 96 = BD+47_612 = StKM 2-205 = CNS 427 M0V: Stephenson86 *M0.5V: Boeshaar76(stan),Hawley97,Lepine13 M0.7: Mann15 M1: Lee47 M1.5V: Joy74 M2V: Vyssotsky46, Gaidos14(M2) V=9.40(HIP), V=9.387+-0.033(Mermilliod91), B-V=1.466+-0.031(HIP), B-V=1.497+-0.009(Mermilliod91), U-B=1.180(Mermilliod91), V-I=1.88+-0.14(HIP), J=6.377+-0.019(2MASS), H=5.770+-0.038(2MASS), Ks=5.554+-0.026(2MASS), V-Ks= 9.40 - 5.554 = 3.846. plx=83.75+-1.14mas(vanLeeuwen07) => Mv = 9.02. Teff=3650K(Lepine13), 3770K(Morales08), 3785+-62K(Mann15#1), 3892+-38K(Mann15#2), 4058+-73K(Gaidos14) => Teff = 3840K. [Fe/H]=0.14+-0.08(Mann15). # Tertiary Standard GJ 4B = HD 38B M0V: Adams35,Woolley70(M0),Anosova87 *M0.5V: Joy74,Keenan80,Keenan89,Gliese91,Keenan99,Tamazian06 M2: Lee47 K7: Hawley97(Neves13) plx = 88.44+-1.56mas(vanLeeuwen07). B-V=1.50(Glebocki80), V=8.94(Tycho), Ks=5.284+-0.023(2MASS). B-V=1.379+-0.038(Tycho). plx=88.44+-1.56mas(vanLeeuwen07) => Mv = 8.67. Teffs: 3900K(Morales08). Surprisingly poorly studied star for having been an Keenan standard. I've set it as a tertiary standard as it has only appeared in one major M dwarf over the past two decades, and that survey quotes it as K7 (Hawley97). Note that B appears to be nearly identical to A: Ks(B)=5.284, Ks(A)=5.262, V(A)=8.85, V(B)=8.94, V-Ks(A)=3.588, V-Ks(B)=3.656, hence the stars should be nearly identical spectral types. # Deprecated Standards GJ 172 = HD 232979 = BD+52_857 K6: Abt72(#1) K7: Abt72(#2) K8V(e): Cowley67 *M0V: Keenan85,Gray03 M0.5V: Keenan89 M1V: Joy74,Adams35 Probably not good for a standard given that Keenan moved it from M0V to M0.5V, and not good agreement among authors. Not listed as a Henry02 standard. GJ 720 A = BD+45 2743 = StKM 2-1384 = LHS 3394 = NLTT 46716 K7/M0V: Stephenson86 M0: Vyssotsky46,Bidelman85 *M0.5V: Kirkpatrick91,Alonso-Floriano15 M1: Lepine13,Gaidos14 M2V: Adams35,Joy74 M3: Lee47 Would prefer to see better agreement on spectral type among surveys for a standard star. V=9.84(HIP), B-V=1.415+-0.013(HIP), plx = 64.32+-0.95mas(vanLeeuwen07) => Mv = 8.88. GJ 839 = LHS 3727 = G 215-20 = MCC 72 = K7: Bidelman85 *M0V: Vyssotsky43,Lee47(M0),Stephenson86,Hawley97(M0),Lepine13(M0.0),Gaidos14(M0) M0.5V: Kirkpatrick91(sec.stan.) M1V: Joy74 Surprisingly no other reference classifies the star as M0.5V besides Kirkpatrick91, so I deprecated it as a standard. However, it has a half-dozen independent classifications as M0V. GJ 2155 = LHS 3947 = G 29-33 = HIP 115680 K7V: Stephenson86(Gliese91),Reid95,Hawley97 dKp7.5: Zhong19 M0: Lepine13(M0.0),Gaidos14,Jeffers18,Lu19 *M0.5V: Kirkpatrick91(sec.stan) M1.5+-0.4: Sebastrian21 Msd: vanAltena95(Bidelman) Does not seem to be good agreement on subtype, ranging from K7 to M1.5, even with Kirkpatrick91 calling it a standard. Appears to be labeled "sdM" in some references, but not primary classifications (HIP,Bobylev06). However Gaidos14 reports [Fe/H]=-0.07+-0.12. Teff: 3700K(Lepine13), 3901+-94K(Gaidos14). V=10.54(GCTP), V=10.551+-0.011(Mermilliod91), V=10.56(HIP), B-V=1.50(GCTP), B-V=1.461+-0.016(HIP), B-V=1.436+-0.040(Mermilliod91), V-I=1.86+-0.07(HIP), U-B=1.20(GCTP), J=7.763+-0.023(2MASS), H=7.070+-0.034(2MASS), Ks=6.923+-0.011(2MASS). G=9.865685, Bp-Rp=1.856887(GaiaEDR3), Bp-G=0.916925(GaiaEDR3), G-Rp=0.939962(GaiaEDR3). V-Ks = 3.628 = 10.551 - 6.923. plx=44.3565+-0.0299mas(GaiaEDR3) => Mv=8.786, M_G=8.100, M_Ks=5.158. # Other Stars GJ 825 = HD 202560 = AX Mic = Lacaille 8760 = UGP 518 = LHS 66 (J2117-3852) K7.0: Hawley97(Kirkpatrick12) K9.0V: Isaacson17 M0V: Evans57(M0Ve),Upgren72,Bidelman85(M0),Torres06 *M0.5V: Walker83 M1V: Adams26,Joy74,Keenan89(non-stan),Gaidos14(M1) M1/2V: Houk82 Brightest southern M dwarf (V=6.7), and the one "pure" M1V in Keenan89 (although not a standard, although there are two M1V variants). Not really good enough agreement to consider a standard. Note that Joy74's M1V corresponds roughly to M0.5(+-1.0) on the Kirkpatrick91 system (see notes in M0V.txt), and Teff (below) is most similar to M0.5V-ish. Teffs: 3592K(Alonso96), 3599+-52K(Ramirez05), 3776+-80K(Gaidos14), 3796+-18K(Koleva12), 3912K(Moro-Martin15), 3930K(Morales08) => = 3786K. [Fe/H]=-0.62+-0.07(Koleva12), logg=4.55+-0.08(Kovleva12). GJ 572 = G 201-30 = MCC 314 = Ci 18 1996 = Ci 20 904 = G 179-6 = BD+45 2247 = StKM 2-1106 K7: Bidelman85,Reid95 M0V: Vyssotsky52,Joy74,Stephenson86 *M0.5: Lepine13 M1: Gaidos14 Bright and nearby. V=9.2, plx = 85.3753 +- 0.0367 mas (GaiaDR2). # Variant YY Gem = HD 60179 M0.5Ve Fe-2 : Keenan99(not in Keenan88)