M1.5V Kirkpatrick(in GrayCorbally09) call Gl 205 the M1.5V primary standard. This is agreement among many sources (Keenan, Kirkpatrick, Hawley, Reid, Houk) as a M1.5V. Both the primary and secondary standards appear to be metal-rich, with radii larger and absolute magnitudes tenths of a magnitude brighter than average for the type. KeenanMcNeil76 standard: GJ 49 - M1.5V Keenan80 standard: GJ 205 (=HD 36395) - M1.5V Keenan83 standard: GJ 205 (=HD 36395) - M1.5V GJ 570B (=HD 131976) - M1.5V Turnshek85 standard: GJ 205 (=HD 36395) - dM1.5 Keenan85 standard: GJ 205 (=HD 36395) - M1.5V Corbally86 standard: GJ 205 (=HD 36395) - M1.5V Keenan88 standard: GJ 205 (= HD36395) - M1.5V GJ 570B - M1.5V Keenan89 standard: GJ 205 (= HD 36395) - M1.5V GJ 570B (=HD 131976) - M1.5V Kirkpatrick91 standard: GJ 205 (=HD 36395) - M1.5V Henry02 standards: GJ 15A - M1.5V (from Henry94) GJ 205 - M1.5V (from Kirkpatrick91) GJ 526 - M1.5V (from Henry94) GJ 625 - M1.5V (from Henry94) GJ 880 - M1.5V (from Henry94) GrayAtlas standard: BD+43_44A - M1.5V GrayNstars standard: GJ 570B (=HD 131976) - M1.5V Kirkpatrick(in GrayCorbally09): GJ 205 - M1.5V GJ 570B - M1.5V Joy74 M1.5V stars appear to be approximately M1-V (~M0.75+-1 subtype) on the Kirkpatrick91 system. (B-V)(M1.5V) = 1.415 ; exemplar GJ 366 = Ross 434 (B-V)(M1.5V) = 1.448 ; deprecated stan. GJ 526 (B-V)(M1.5V) = 1.464 ; exemplar GJ 908 = LHS 550 (B-V)(M1.5V) = 1.474 ; pri. stan. GJ 205 (Landolt83) (B-V)(M1.5V) = 1.512 ; sec. stan. GJ 880 (Mermilliod91) (B-V)(M1.5V) = 1.567 ; deprecated stan. GJ 15A (V-I)(M1.5V) = 2.15 ; Hawley96 (V-I)(M1.5V) = 2.076 ; pri. stan. GJ 205 (Landolt83) (M1.5V) = 3.36 (+-0.23 stdev) ; Lepine12 (V-Ks)(M1.5V) = 4.156 ; pri. stan. GJ 205 (estimated from V-R color) (V-K)(M1.5V) = 4.15 ; Hawley96 (V-Ks)(M1.5V) = 4.149 ; sec. stan. GJ 880 (V-Ks)(M1.5V) = 4.116 ; exemplar GJ 134 = HD 275122 (V-Ks)(M1.5V) = 4.104 ; pri. stan. GJ 205 (from synthetic Ks mag from Mann15) (V-Ks)(M1.5V) = 4.102 ; pri. stan. GJ 205 (estimated from V-I color) (V-Ks)(M1.5V) = 4.045 ; ter. stan. GJ 526 (V-Ks)(M1.5V) = 4.014 ; pri. stan. GJ 205 (estimated from B-V color) (V-Ks)(M1.5V) = 3.986 ; exemplar GJ 366 = Ross 434 (V-Ks)(M1.5V) = 3.940 ; exemplar GJ 908 = LHS 550 => adopt (V-Ks)(M1.5V) = 4.10 [last updated 11/1/2019] => adopt (U-B)(M1.5V) = 1.171 => adopt (B-V)(M1.5V) = 1.484 => adopt (V-I)(M1.5V) = 2.075 => adopt (V-R)(M1.5V) = 0.974 => adopt (R-I)(M1.5V) = 1.101 => adopt (V-J)(M1.5V) = 3.265 => adopt (V-H)(M1.5V) = 3.873 => adopt (H-Ks)(M1.5V) = 0.227 => adopt (J-H)(M1.5V) = 0.608 => adopt (I-Ks)(M1.5V) = 2.031**fix => adopt (K-W1)(M1.5V) = 0.140 (G-J)(M1.5V) = 2.312 ; Bentley18/interp (G-Ks)(M1.5V) = 3.162 ; Bentley18/interp (Ks-W2)(M1.5V) = 0.226 ; Bentley18/interp (W1-W2)(M1.5V) = 0.080 ; Bentley18/interp (Ks-W1)(M1.5V) = 0.147 ; Bentley18/interp (Ks-W1)(M1.5V) = 0.140 ; fit to Winters15 data for V-Ks=4.10 (Ks-W1)(M1.5V) = 0.110 ; Best18 (Ks-W1)(M1.5V) = 0.099 ; Avenhaus12 for V-Ks=4.10 => adopt (Ks-W1)(M1.5V) = 0.135 [updated 12/29/2019] (Bp-Rp)(M1.5V) = 2.1174 ; BD+18_3421 (Bp-Rp)(M1.5V) = 2.1130 ; GJ_526 ter. stan. (Bp-Rp)(M1.5V) = 2.1257 ; GJ_205 pri. stna. (Bp-Rp)(M1.5V) = 2.1553 ; GJ_880 sec. stan. (Bp-Rp)(M1.5V) = 2.1649 ; MCC_135 (Bp-Rp)(M1.5V) = 2.1731 ; V*_GX_And (Bp-Rp)(M1.5V) = 2.1805 ; BD+61_195 (Bp-Rp)(M1.5V) = 2.2773 ; CD-48_11837 (Bp-Rp)(M1.5V) = 2.3033 ; HD_156384C => adopt (Bp-Rp)(M1.5V) = 2.14 [updated 3/1/2019] (G-Rp)(M1.5V) = 1.0165 BD+18_3421 M1.5V (G-Rp)(M1.5V) = 1.0174 ; GJ_205 pri. stan. (G-Rp)(M1.5V) = 1.0205 ; GJ_526 ter. stan. (G-Rp)(M1.5V) = 1.0278 MCC_135 M1.5V (G-Rp)(M1.5V) = 1.0291 ; GJ_880 sec. stan. (G-Rp)(M1.5V) = 1.0309 BD+61_195 M1.5V (G-Rp)(M1.5V) = 1.0340 V*_GX_And M1.5V (G-Rp)(M1.5V) = 1.0643 CD-48_11837 M1.5V (G-Rp)(M1.5V) = 1.0690 HD_156384C M1.5V => adopt (G-Rp)(M1.5V) = 1.03 [updated 3/1/2019] => adopt (Bp-G)(M1.5V) = 1.11 [updated 3/1/2019; Bp-Rp=2.14, G-Rp=1.03] (Bp-G)(M1.5V) = 1.0925 ; GJ_526 (Bp-G)(M1.5V) = 1.1084 ; GJ_205 (Bp-G)(M1.5V) = 1.1262 ; GJ_880 (G-V)(M1.5V) = -0.8695 ; GJ_205 (G-V)(M1.5V) = -0.8532 ; GJ_526 (G-V)(M1.5V) = -0.8449 ; GJ_880 => adopt (G-V)(M1.5V) = -0.85 [updated 12/10/2018] => adopt (G-Ks)(M1.5V) = 4.12 + -0.85 = 3.27 [updated 11/1/2019] => adopt M_G(M1.5V) = 9.05 = Mv + (G-V) = 9.90 + -0.85 [updated 4/9/2020] Teff(M1.5V) = 3533 K ; Morrell19 for stars w/i +-0.05 mag of M_Ks=5.82 Teff(M1.5V) = 3535 +- 14 K ; Pecaut13 (deprecated stan. GJ 15A) Teff(M1.5V) = 3564 +- 44 K ; Lepine12 Teff(M1.5V) = 3563 +- 11 K ; deprecated standard GJ 15A (Boyajian12) Teff(M1.5V) = 3596 +- 25 K ; Pecaut13 (GJ 880) Teff(M1.5V) = 3600 K ; Rajpurohit13 (N=2; LHS 14A, LHS 65A) Teff(M1.5V) = 3610 K ; Rad=0.4743Rsun for Mann15 calib for M_Ks=5.8, [Fe/H]=0.0 Teff(M1.5V) = 3640 K ; empirical L-R relation, logL=-1.464 Teff(M1.5V) = 3650 K ; ter. stan. GJ 526 Teff(M1.5V) = 3674 +- 10 K ; Boyajian12b (N=4) Teff(M1.5V) = 3683 K ; smooth Teff(SpT) trend Teff(M1.5V) = 3703 +- 36 K ; Pecaut13 (GJ 205) Teff(M1.5V) = 3750 K ; sec. stan. GJ 880 (median Teff, but metal-rich) Teff(M1.5V) = 3760 K ; pri. stan. GJ 205 (median Teff, but metal-rich) => adopt Teff (M1.5V) = 3610 K (logT = 3.561) [updated 4/9/2020] BCv(M1.5V) = -1.529 +- 0.022 ; deprecated standard GJ 15A (Pecaut13) BCv(M1.5V) = -1.523 +- 0.019 ; pri. stan. GJ 205 (Pecaut13) BCv(M1.5V) = -1.50 ; BC_Ks=2.60, V-Ks=4.10 BCv(M1.5V) = -1.494 +- 0.024 ; sec. stan. GJ 880 (Pecaut13) BCv(M1.5V) = -1.432 +- 0.019 ; non-standard GJ 526 (Pecaut13) => adopt BCv(M1.5V) = -1.50 [updated 11/3/2019; BC_K=2.60, V-K=4.10] BC_K(M1.5V) = 2.541 ; smoothed trend over M0V-M9V for M1V BC_Ks(M1.5V)= 2.596 ; Mann15 for V-J=3.265 BC_Ks(M1.5V)= 2.603 ; Morrell19 trend for G-Ks=3.27 BC_K(M1.5V) = 2.613 +- 0.021 ; non-stan GJ 526 (Pecaut13) BC_K(M1.5V) = 2.655 +- 0.026 ; sec. stan. GJ 880 (Pecaut13) => adopt BC_K(M1.5V) = 2.60 [updated 11/3/2019] Mv(M1.5V) = 9.14 ; Kirkpatrick94 Mv(M1.5V) = 9.19 ; pri. stan. GJ 205 (metal-rich) Mv(M1.5V) = 9.26 ; exemplar GJ 134 = HD 275122 Mv(M1.5V) = 9.49 ; sec. stan. GJ 880 = HD 216899 (metal-rich) Mv(M1.5V) = 9.62 ; exemplar GJ 366 = Ross 434 Mv(M1.5V) = 9.78 ; EEM fit to Jao16 data for V-Ks=4.10 Mv(M1.5V) = 9.89 ; Finch14 calibration for V-Ks=4.10 Mv(M1.5V) = 9.91 ; JohnsonApps09 calibration for V-Ks=4.10 Mv(M1.5V) = 9.94 ; Dieterich14 calibration for V-Ks=4.12 Mv(M1.5V) = 10.02 ; Henry04 calibration for V-Ks=4.10 => adopt Mv(M1.5V) = 9.90 [updated 11/3/2019; V-Ks=4.10, M_Ks=5.80] M_Ks(M1.5V) = 5.82 ; Dieterich14 calibration for V-Ks=4.12 M_Ks(M1.5V) = 5.82 ; EEM calib for Winters15 data for V-Ks=4.12 M_Ks(M1.5V) = 5.81 ; JohnsonApps09 calibration for V-Ks=4.10 M_Ks(M1.5V) = 5.79 ; Finch14 calibration for V-Ks=4.10 M_Ks(M1.5V) = 5.68 ; Jao16 calibration for V-Ks=4.10 M_Ks(M1.5V) = 5.64 ; exemplar GJ 366 = Ross 434 M_Ks(M1.5V) = 5.34 ; sec. stan. GJ 880 = HD 216899 M_Ks(M1.5V) = 5.15 ; exemplar GJ 134 = HD 275122 => adopt M_Ks(M1.5V) = 5.80 [updated 11/3/2019; V-Ks=4.10, Mv=9.90] logL(M1.5V) = -1.473 ; Morrell19 trend for logL for M_Ks=5.82 logL(M1.5V) = -1.464 ; M_Ks=5.80, BC_Ks=2.60, MBbol = 8.40 => adopt logL(M1.5V) = -1.464 [updated 11/3/2019] => adopt Mbol(M1.5V) = 8.400 [updated 11/3/2019] Rad(M1.5V) = 0.566+-0.002 Rsun ; pri. stan. GJ 205 = HD 36395 (Rabus19) [metal rich] Rad(M1.5V) = 0.574+-0.004 Rsun ; pri. stan. GJ 205 = HD 36395 (Yee17) [metal rich] Rad(M1.5V) = 0.549 Rsun ; sec. stan. GJ 880 = HD 216899 [metal-rich] Rad(M1.5V) = 0.548+-0.005 Rsun ; sec. stan. GJ 880 = HD 216899 (Yee17) [metal-rich] Rad(M1.5V) = 0.4979+-0.0026 Rsun ; Boyajian12b (N=4) Rad(M1.5V) = 0.483 Rsun ; Rabus19 trend for Teff=3640K Rad(M1.5V) = 0.4743 Rsun ; Mann15 trend M_Ks=5.80, [Fe/H]=0.0 Rad(M1.5V) = 0.4738 Rsun ; logL=-1.464, Teff=3610K Rad(M1.5V) = 0.3874+-0.0023 Rsun ; deprecated standard GJ 15A (Boyajian12) => adopt Rad(M1.5V) = 0.474 Rsun [updated 4/9/2020] Mass(M1.5V) = 0.405+-0.008 Msun ; pri. of GJ22AC, unresolved SpT=M1.5V (Benedict16) Mass(M1.5V) = 0.462 Msun ; Benedict16 calib. for Mv=9.94 Mass(M1.5V) = 0.471 Msun ; Mann18 calib. for M_Ks=5.80 Mass(M1.5V) = 0.490 Msun ; Delfosse00 calib. for M_Ks=5.80 Mass(M1.5V) = 0.531 Msun ; Benedict16 calib. for M_Ks=5.80 Mass(M1.5V) = 0.586+-0.007 Msun ; GJ570B (Benedict16) Mass(M1.5V) = 0.600+-0.006 Msun ; GU Boo B (Benedict16) Mass(M1.5V) = 0.610 Msun ; Torres10 calib. for Mv=9.94 => adopt Mass(M1.5V) = 0.47 Msun [updated 11/3/2019] # No Standard Boeshaar85 does not list an M1.5V standard. # Primary Standard GJ 205 = HD 36395 = LHS 30 M1V: JM53(non-stan.,"dM1") *M1.5Ve: Boeshaar76,KeenanMcNeil76(stan),Keenan85,Corbally86(stan,Keenan80),Keenan88,Kirkpatrick91(pri),Hawley97,Keenan99,Houk99,Henry02,Reid04,Mann15 M2.33: Terrien15 Excellent recent agreement on type, and has interferometric diameter and Teff estimates. Appears to be metal-rich [Fe/H] ~ +0.4. Segransan03 VLTI study reports: M = 0.631+-0.031 Msun, R=0.702+-0.063 Rsun, Teff = 3520+-170 K, logg=4.54+-0.06 dex. KeenanMcNeil76 do not list Gl 205 as a standard in their Table 3, however they do show it as a M2 dwarf in their Plate 19. V=7.966+-0.011(Mermilliod91), V=7.960(Landolt83), B-V=1.474+-0.009(Mermilliod91), B-V=1.474(Landolt83), U-B=1.213+-0.024(Mermilliod91), U-B=1.231(Landolt83), V-R=0.985(Landolt83), R-I=1.095(Landolt83), V-I=2.076(Landolt83). Unfortunately all 2MASS photometry is saturated, but Mann15 fits synthetic 2MASS magnitudes: J=4.796+-0.017, H=4.123+-0.017, Ks=3.856+-0.019. Teffs: 3520+-170K(Segransan03), 3708K(Prugniel07#2), 3719K(Prugniel07#1), 3732+-56K(Ramirez05), 3737K(Alonso96), 3760K(Wolff05), 3801+-60K(Mann15), 3835+-69K(Rabus19), 3850+-22K(Newton15#1), 3872K(Newton15#2), 4012+-106K(Rojas-Ayala12) => = 3760K. R=0.5735+-0.044Rsun(Newton14), R=0.581+-0.019Rsun(Mann15), logL=-1.1905+-0.0094(Newton14), M=0.633+-0.063Msun(Mann15), [Fe/H]=0.49+-0.08(Mann15). plx=175.4287+-0.0672mas(GaiaDR2). Mv=9.19+-0.01(Mermilliod91,GaiaDR2). Boyajian12 reports tetLD=0.943+-0.004mas. Boyajian12+GaiaDR2 => Rad = 0.578Rsun. Rabus19: tetLD=0.924+-0.003mas, fbol=(6.140+-0.400)e-8, Rad=0.566+-0.002Rsun, Teff=3835+-69K. [Fe/H] = 0.35+-0.17(RoyasAyala12), 0.43+-0.08(Gaidos14), 0.69(Terrien15, seems too high!), 0.49+-0.08(Mann15). # Secondary Standard GJ 880 = HD 216899 = BD+15_4733 = Ross 671 M1.43: Terrien15(epoch#1) *M1.5V: Henry94,Hawley97,Henry02(stan),Reid04,Kirkpatrick12(KirkpatrickPhD),Lepine13,Mann15 M1.78: Terrien15(epoch#2) M2: Vyssotsky56,Bidelman85 M2.5V: Joy74 V=8.672+-0.013(Mermilliod91), V=8.66(Weis93), B-V=1.512+-0.006(Mermilliod91), B-V=1.50(Weis93), V-R=1.06(Weis93), R-I=0.87(Weis93), U-B=1.175+-0.010(Mermilliod91), J=5.360+-0.020(2MASS), Ks=4.523+-0.016(2MASS), V-Ks=8.672-4.523=4.149+-0.021(Mermilliod91,2MASS). 2MASS H-band is flagged 'E'. mbol=7.178+-0.020(Pecaut13). BC_Ks = mbol - Ks = 7.178 - 4.523 = 2.655+-0.026. BCv = mbol - V = 7.178 - 8.672 = -1.494+-0.024. Teff = 3520K(Lepine13), 3720+-60K(Mann15#1), 3731+-16K(Newton15#2), 3749+-76K(Newton15#2), 3759K(Alonso96), 3760+-35K(Mann15#2), 3808+-70K(Ramirez05) => =3750K. R=0.5490+-0.0180Rsun(Mann15), R=0.5477+-0.0048Rsun(Newton15), R=0.548+-0.005Rsun(Therrien15), M=0.5740+-0.0570Msun(Mann15), [Fe/H]=0.21+-0.08 (more Mann15 numbers), logL=-1.2856+-0.0049(Newton15). Boyajian12 reports tetLD=0.744+-0.004mas. plx=145.6107+-0.0388mas(GaiaDR2). Boyajian12+GaiaDR2 => Rad =0.549Rsun. Rad=0.548+-0.005Rsun(Yee17). Metallicities are all over the place, but the star has a large radius and is probably metal-rich, as some recent results have been indicating - probably [Fe/H] ~ +0.1.: [Fe/H]= -1.50(Alonso96), -0.01+-0.09(Maldonado19), +0.026+-0.080(Hojjatpanah19), +0.06+-0.10(Yee17), +0.07(Neves13), +0.12+-0.16(Schweitzer19), +0.18+-0.11(Gaidos14), +0.20+-0.05(Lindgren17). Mv=9.488+-0.013(Mermilliod91,GaiaDR2), M_Ks=5.339+-0.016(2MASS,GaiaDR2). # Tertiary Standard GJ 526 = HD 119850 = StKM 2-980 = LHS 47 M1: Gaidos14 M1.4: Mann15 *M1.5V: Bidelman85(M1.5),Henry94,Hawley97,Henry02(stan) M2V: Keenan85,Keenan88,Keenan89,GrayNstars,Newton14(near-IR) M3V: Joy74,Stephenson86 Reasonable agreement between Henry, Hawley, and Mann, although notably Keenan and Newton place the type 0.5 later. Colors and Teffs consistent with the other M1.5V standards. (B-V)=1.448+-0.017(Mermilliod91), V=8.460+-0.014(Mermilliod91), (U-B)=1.099+-0.023(Mermilliod91). 2MASS photometry, only K band is flagged as A quality: Ks=4.415+-0.017(2MASS). V-Ks = 8.460 - 4.415 = 4.045. mbol=7.028+-0.013(Pecaut13). BC_Ks = mbol - Ks = 7.028 - 4.415 = 2.613+-0.021. Teffs: 3570+-16K(Pecaut13), 3618K(Boyajian12), 3623K(Prugniel07), 3646+-34K(Newton14), 3650K(Woolf05), 3664+-153K(vanBelle09), 3680K(Prugniel07#2), 3716+-125K(Newton14#2), 3792+-92K(Gaidos14) => = 3650K. [Fe/H]=-0.31+-0.08(Mann15), -0.18+-0.09(Gaidos14), [Fe/H]=-0.10, -0.33(Prugniel07, 2 values), [Fe/H] = -0.10+-0.07(Woolf05). Star is apparently somewhat metal poor. # Deprecated Standards GJ 15A = BD+43_44A = GX And = HD 1326A M1V: JM53(non-standard),Hawley97,Reid04 *M1.5V: GrayAtlas,Boeshaar94,Kirkpatrick94,Henry94(not standard),Henry02 M2V: Keenan85,Keenan88,Keenan99,Sozetti02 Keenan repeatedly classified GJ 15A as M2, but everyone else considers it M1 or M1.5. V=8.089+-0.017(Mermilliod91), B-V=1.567+-0.014(Mermilliod91), U-B=1.222+-0.026(Mermilliod91). Segranson03 VLTI study: M=0.414+-0.021 Msun, R=0.383+-0.02 Rsun, Teff = 3698+-95 K, logg=4.89+-0.06 dex. fbol = (5.420+-0.044)e-8 erg/cm/s^2 (Boyajian12), L = 0.02173+-0.00021 Lsun (Boyajian12), Teff=3563+-11 K (Boyajian12), R = 0.3874+-0.0023 Rsun (Boyajian12). [Fe/H]=-0.36 (Neves11). 2MASS photometry poor. GJ 570B = HD 131976 M1.5V: Keenan85,Keenan88,GrayNstars *M1.0VJ: Henry02 GJ 570BC = LHS 386 = HD 131976 = BD-20 4123 = Lalande 27173BC M0.5: Bidelman85 M1.0V: Walker83,Henry94(Kirkpatrick12),Hawley97,Henry02("joint"),Geballe02,Houdebine12(dM1) *M1V+M3:V: Kirkpatrick12 M1.0V+M1.0V: Reid04 M1.5V: Keenan85,Keenan89(stan),Gray06 M1.5V+M3V: Pourbaix/SB9 M2V: Vyssotsky56,Cowley67,Joy74,Stephenson86,Gaidos14,Newton14 M2III: Houdebine10(prob. because of poor parallax) Unfortunately Keenan considered M1.5, but Henry considers M1. I deprecate the Keenan type as the Henry types have become modern standards. 0.0437" binary according to Tokovinin15, with delta(y)=1.6, and SB orbit from Forvielle99 (Period 308 days). 25" away from primary HR 5568 (HD 131977). Forveille99 splits the BC components, with M_J(B) = 6.213+-0.033, M_J(C) = 7.403+-0.039, and M_K(B) = 5.396+-0.033, M_K(C) = 6.576+-0.039, so delta(K) = 1.18. Given this delta(mag), it likely that the companion is >2 subtypes later, similar to what Pourbaix reports. Forvielle99 section 4 discusses the IR photometry for the pair in more detail. Magnitudes are unresolved unless specifically stated: V=8.065(Koen10), B-V=1.494(Koen10), U-B=1.200(Koen10), V-Rc=0.990(Koen10), V-Ic=2.122(Koen10). Mass=0.586+-0.007Msun(Torres10), R=0.52+-0.05Rsun(Gaidos14). Teffs: 3454+-50K(Houdebine12), 3500+-100K(Torres10), 3506K(Cenarro01,Sanchez-Blazquez06,Cenarro07), 3650K(Stelzer13), 3788+-88K(Gaidos14) => 3506K. [Fe/H]=0.10+-0.13, 0.12+-0.02(Newton14). Note that GJ 570A appears to roughly solar metallicity. Forvielle99 derives dynamical masses of M(B) = 0.586+-0.007 Msun, M(C) = 0.390+-0.005. GJ 49 = G 243-052 = LHS 1179 = HIP 4872 M1.5V: KeenanMcNeil76(stan),Garcia89,Hawley97 M2V: Gunn83,Joy74,Vyossotsky43 *M2+V: Gray03 M1: Bidelman85(Kuiper) K5V: LjunggrenOja61(Jaschek64,Jaschek78),Sjogren64 M3: Lee47 Not sure why this star not used as an M1.5V standard after KeenanMcNeil76. vanLeeuwen07 plx = 100.40+-1.52 mas. V=9.552+-0.015 (Mermilliod91), B-V=1.503+-0.005(Mermilliod91), U-B=1.21+-0.058(Mermilliod91). J=6.230+-0.021(2MASS), H=5.582+-0.024(Mermilliod91), Ks=5.371+-0.020(2MASS). # Exemplars GJ 908 = LHS 550 = BR Psc = HIP 117473 = Lal 46650 M0V: Newton14(near-IR) M1V: Stephenson86,Henry94,Hawley97,Henry02 M1V Fe-1: Keenan89 M1.4: Mann15 *M1.5V: Bidelman85(M1.5),Lepine13 M2V: Vyssotsky43,JM53(non-stan),Cowley82(M2Ve),Torres06,Gaidos14 M2.5Ve: Joy74 M3: Lee47 Type has mostly oscillated between ~M1 and ~M2 over the years. : [Fe/H]=-0.95+-0.19, as does Mann15 [Fe/H]=-0.45+-0.08. V=8.983+-0.012(Mermilliod91), B-V=1.464+-0.028(Mermilliod91), U-B=1.104+-0.025(Mermilliod91), J=5.827+-0.023(2MASS), H=5.282+-0.031(2MASS), Ks=5.043+-0.020(2MASS). V-Ks=3.940(Mermilliod91,2MASS). mbol = 7.503+-0.025 (JHK => Casagrande08 calib.) => BCv = -1.48, BC_K = 2.46. Plx = 167.29+-1.23 mas. Mv=10.10+-0.02(Mermilliod91, vanLeeuwen07), M_Ks=6.16+-0.03(2MASS,vanLeeuwen07). This star was also modeled by Leggett96: flux = 2.50e-11 W/m^2, logL=-1.59, mbol=7.53, Mbol=8.74, BCv=-1.45, BC_K=2.48. Teffs: 3646+-60K(Mann15#1), 3700+-150K(Leggett96), 3704+-29K(Mann15), 3712+-85K(Gaidos14) => adopt Teff=3700K. Nice to see the Leggett96 and Casagrande08-derived mbol agree at the +-0.03 mag level! GJ 134 = HD 275122 = Wolf 1325 = LHS 1528 = HIP 15366 = 2MASS J03180742+3815081 = G 95-25 = G 78-31 = LTT 11082 K7: Cannon49 *M1.5V: Joy74,Bidelman85(M1.5),Reid95/Hawley97(M1.5),Lurie13(M1.5),Mann15(M1.5) M2V: Vyssotsky46,Gaidos14(M2) M3: Lee47,Stephenson86(M3:) V=10.280(Mermilliod91), B-V=1.475(Mermilliod91), U-B=1.205(Mermilliod91). Ks=6.164+-0.020(2MASS), V-Ks = 10.280 - 6.164 = 4.116. plx=62.5647+-0.0720mas(GaiaDR2). Mv=9.26(Mermilliod91,GaiaDR2). M_Ks=5.146+-0.020(2MASS,GaiaDR2). GJ 366 = Ross 434 = LHS 2188 = HIP 47981 = G 252-44 = G 253-30 = LTT 12585 = NLTT 222468 = 2MASS J09464844+7602388 M1: Lee47 *M1.5V: Joy74,Bidelman85(M1.5),Reid95(M1.5),Lurie13(M1.5) M2V: Vyssotsky46,Gaidos14(M2) V=10.615+-0.015(Mermilliod91), V=10.64(Weis93), B-V=1.415+-0.015(Mermilliod91), B-V=1.40(Weis93), V-R=1.02(Weis93), R-I=0.87(Weis93), U-B=1.09+0.01(Mermilliod91), Ks=6.629+-0.024(2MASS), V-Ks=10.615 - 6.629 = 3.986. plx=63.3142+-0.0302mas. Mv = 9.623+-0.015 , M_Ks= 5.637+-0.024. LHS 2429 LHS 1828 G 242-48 BD+61 195 GJ 3098 GJ 87 tet Per B 2MASS J08175130+3107455 2MASS J14562809+1648342 GJ 625 # Other Stars RECONS list shows GJ 887 (J2305-3551) as the nearest M1.5V star, followed by GJ 15A (J0018+4401), & GJ 191 (J0511-4501).