M3V GJ 752A appears to be the best M3V standard. Unfortunately, it is a bit hotter and bluer than the rest of the M3V standards and M3V-classified field stars. Note that some standards are classified as "M3-V", and following KeenanMcNeil76, "M3-V" should be translated as "M2.75V". Jao18 reports a gap in the color-mag diagram for M dwarfs using the GaiaDR2 data ("the gap progresses from M_G~ 10.09 in the G_BP−G_RP=2.35–2.40 bin to ∼10.24 in the 2.55–2.60 bin." If one looks at the cumulative distribution of absolute magnitudes M_G for stars within the 10 pc in the Gaia-CNS catalog, the gap is sizeable (~0.29 mag) and bounded by: M_G = 10.13 (GJ 251 M3V standard; Teff=3448+-60K, R=0.358+-0.013Rsun, M=0.352+-0.035Msun; Mann15) and M_G = 10.42 (GJ 581 M2.5V standard; Teff=3395+-60K, R=0.311+-0.012Rsun, M=0.292+-0.029Msun; Mann15). JaoFeiden20 tags the gap at M_G ~ 10.3 and shows its color dependence (brighter at blue end, stretching approximately from (Bp-Rp=2.3,M_G=10.0) to (Bp-Rp=2.7,M_G=10.3). This 0.29 mag empty gap in M_G stands out among the 10pc sample as the 0.1 mag M_G bins brighter (10.03-10.13) and fainter (10.42-10.52) than those limits contain 10 and 4 stars, respectively. Note that Rabus19 points out a discontinuity in the region Teff=3200K-3340K where M dwarf radii 0.18 to 0.42 Rsun. M3V (mean Teff ~ 3440K) is just hotward of this region, although some of the cooler M3Vs may be in this overlap region. As seen below, the measured radii for the M3V standards and exemplars span ~0.32-0.47 Rsun. I adopt the Mann15 [Fe/H]=0.0 radius for M_K=6.5 to guide estimation of the mean HRD point. Mode of absolute magnitude distribution [7/12/2022]: Among the SIMBAD stars within 20pc with default Gaia G mags & parallaxes, the mode of the distribution of absolute G magnitudes (M_G) appears to be near ~M3-M3.5V. The densest absolute magnitude range is peaked at M_G=10.5145 (with LP_783-1 = LHS 1935 appearing at the peak). There are 23 stars with M_G between 10.50-10.53 within 20 pc! Boeshaar76 standard: GJ 752A - M3V KeenanMcNeil76 standard: G 5-43 - M3V Keenan80 standard: GJ 752A (=HD 180617) - M3-V Keenan83 standard: GJ 752A (=HD 180617) - M3-V Boeshaar85 standard: GJ 725A (=HD 180617) - M3V Keenan85 standard: GJ 752A (=HD 180617) - M3-V Keenan88 standard: GJ 752A (=HD 180617) - M3-V Keenan89 standard: GJ 752A (=HD 180617) - M3-V Kirkpatrick91 standard: GJ 352AB - M3V (primary stan.) GJ 436 - M3V (primary stan.) GJ 251 - M3V (primary stan.) GJ 752A - M3V (primary stan.) GJ 725A - M3V (primary stan.) GJ 22B - M3V (secondary stan.) GJ 569A - M3V (secondary stan.) Kirkpatrick94 standard: GJ 725A (=HD 173739) - M3V GJ 22B (BD+66 34B) - M3V Hawley02 standard: GJ 251 - M3V Henry02 standards: GJ 22B - M3.0V (cites McCarthy91) GJ 109 - M3.0V (cites Henry94) GJ 251 - M3.0V (cites Kirkpatrick91) GJ 352AB - M3.0VJ (cites Kirkpatrick91) GJ 436 - M3.0V (cites Kirkpatrick91) GJ 628 - M3.0V (cites Henry94) GJ 661AB - M3.0VJ (cites Henry94) GJ 687 - M3.0V (cites Henry94) GJ 725A - M3.0V (cites Kirkpatrick91) GJ 752A - M3.0V (cites Kirkpatrick91) GJ 860A - M3.0V (cites Henry94) Kirkpatrick(in GrayCorbally09): GJ 752A - M3V Kirkpatrick10 GJ 752A - M3V (optical,near-IR) Pecaut13 standard: GJ 752A - M3-V Kirkpatrick16 standard: GJ 436 (=Ross 905) - M3V Boeshaar76 and Kirkpatrick91 agree on M3V for two: GJ 436 & 752A GJ 752A is probably the best, although JM53 called it M3.5V and Keenan88 called it M3-V. I give more weight than the others as it is only one that both Joy, Boeshaar, & Kirkpatrick all called M3V, and Keenan had it within 0.25 type (M3-V). Note that it is bluer and brighter than the other M3V "standards", so it could be considered "M3-V" compared to the swarm. Adams26 (1926ApJ....64..225A) classified 7 dwarfs with types "M3", but only one is considered a M3V standard in recent literature - GJ 860A (Kruger 60A = HD 239960 = BD+56 2783) - while the rest have M0V through M2.5V modern classifications. There is general agreement between Kirkpatrick/Henry & Hawley/Reid for M3V types for GJ 102 and GJ 860A plus a few unresolved binaries, but also some differences with other authors also. Skiff08 does not flag any stars as M3V MK standards. RECONS list shows GJ 725A (J1842+5937; B-V=1.504; HIP) as the nearest M3.0V star, followed by GJ 860A (B-V=1.613; HIP, unresolved), GJ 687 (B-V=1.505; HIP), GJ 251 (B-V=1.58+-0.04; HIP), GJ 693 (B-V=1.660; HIP), GJ 581 (B-V=1.600; HIP), and GJ 661 A (B-V=1.485; HIP) -- (all within the nearest 100 stars). Be careful not to get some of these Gliese standards confused. Kirkpatrick(GrayCorbally09) lists Gl 752A as the M3V standard, Gl 725B as the M3.5V standard, and Gl 752B (=vB 10) as the M8V standard. I'm a bit picky here -- I advocate GJ 752A clearly as the primary standard (following Kirkpatrick), but I'm not quite content with any of the other M3V standards. For the time being, I'll stick with GJ 752A. (M3V) = 1.464 ; pri. stan. GJ 752A (M3V) = 1.47 ; Fitzgerald70 (B-V)(M3V) = 1.480 ; deprecated standard GJ 569A (B-V)(M3V) = 1.485 ; GJ 661A ; M3.0V in RECONS list of nearest 100 *s (B-V)(M3V) = 1.49 ; Vyssotsky63 (B-V)(M3V) = 1.49 ; JohnsonMorgan53 (B-V)(M3V) = 1.493 ; sec. stan. GJ 436 (B-V)(M3V) = 1.504 ; sec. stan. GJ 725A (B-V)(M3V) = 1.505 ; ter. stan. GJ 687 (B-V)(M3V) = 1.51 ; SchmidtKaler82 (B-V)(M3V) = 1.525 ; median SIMBAD M3V d<25pc (N=177) (B-V)(M3V) = 1.527 (+-0.008 sem,+-0.053 stdev); med. for 25 ARICNS M3V stars (B-V)(M3V) = 1.54 ; median among M3V stars among 100 nearest (see below) (B-V)(M3V) = 1.543 ; Koen10 d<25pc median M3V (M3V) = 1.55 ; Johnson66 (B-V)(M3V) = 1.55 ; KenyonHartmann95 (B-V)(M3V) = 1.55 ; Bessell91 "old disk" (B-V)(M3V) = 1.55 ; Leggett92 "young disk" (B-V)(M3V) = 1.550 ; ter. stan. GJ 109 (M3V) = 1.557 ; 8 Gray03/06 M3Vs (+-0.021 sem, +-0.070 stdev) (M3V) = 1.577 ; ShayaOlling11 (B-V)(M3V) = 1.58 ; GJ 251 ; M3.0V in RECONS list (B-V)(M3V) = 1.582 ; exemplar GJ 3459 = LHS 1935 = LP 783-1 (B-V)(M3V) = 1.600 ; GJ 581 ; M3.0V in RECONS list (B-V)(M3V) = 1.613 ; GJ 860A ; M3.0V in RECONS list (but B-V unresolved) (B-V)(M3V) = 1.660 ; GJ 693 ; M3.0V in RECONS list => adopt (B-V)(M3V) = 1.53 [updated 7/5/2020] (M3V) = 1.15 ; Johnson66 (U-B)(M3V) = 1.10 ; JohnsonMorgan53 (M3V) = 1.60 ; Johnson66 (V-R)(M3V) = 1.10 ; Bessell91 "old disk" (R-I)(M3V) = 1.37 ; Bessell91 "old disk" (G-J)(M3V) = 2.564 ; Bentley18 (G-Ks)(M3V) = 3.416 ; Bentley18 (Ks-W2)(M3V) = 0.294 ; Bentley18 (W1-W2)(M3V) = 0.146 ; Bentley18 (Ks-W1)(M3V) = 0.159 ; fit to Winters15 data for V-Ks=4.60 (Ks-W1)(M3V) = 0.148 ; Bentley18 (Ks-W1)(M3V) = 0.140 ; Avenhaus12 for V-Ks=4.60 (Ks-W1)(M3V) = 0.130 ; Best18 => adopt (Ks-W1)(M3V) = 0.15 [updated 12/29/2019] (M3V) = 2.32 ; GJ 752A pri. stan. (V-I)(M3V) = 2.40 ; Leggett92 "young disk" (M3V) = 2.449 (+-0.128 sem, +-0.399 stdev; Gray01/03/06 N=8) (V-I)(M3V) = 2.47 ; Bessell91 "old disk" (V-I)(M3V) = 2.483 ; exemplar GJ 3459 = LHS 1935 = LP 783-1 (V-I)(M3V) = 2.5 ; Hawley96 (M3V) = 2.94 ; Johnson66 (M3V) = 3.537 ; GJ 752A pri. stan. (M3V) = 3.66 ; Johnson66 (M3V) = 3.91 (+-0.28 stdev) ; Lepine12 (V-Ks)(M3V) = 4.38 ; deprecated standard GJ 569A (V-Ks)(M3V) = 4.447 ; pri. stan. GJ 752A (V-Ks)(M3V) = 4.472 ; sec. stan. GJ 725A (V-Ks)(M3V) = 4.56 ; deprecated standard GJ 352 A (V-K)(M3V) = 4.57 ; Johnson66 (V-Ks)(M3V) = 4.58 ; mean of pri. stan. and 3 sec. standards (+-0.055 s.e.m, +-0.12 st.dev) (V-Ks)(M3V) = 4.597 ; sec. stan. GJ 436 (V-K_CIT)(M3V) = 4.60 ; Beuermann06 (V-K_CIT)(M3V) = 4.60 ; Leggett92 "young disk" (V-Ks)(M3V) = 4.62 ; ter. stan. GJ 687 (V-Ks)(M3V) = 4.634 ; ter. stan. GJ 109 (V-Ks)(M3V) = 4.649 ; exemplar GJ 3459 = LHS 1935 = LP 783-1 (V-K)(M3V) = 4.65 ; Bessell91 "old disk" (V-K)(M3V) = 4.7 ; Hawley96 (V-Ks)(M3V) = 4.735 ; exemplar GJ 581 = Wolf 562 (V-Ks)(M3V) = 4.745 ; sec. stan. GJ 251 (V-Ks)(M3V) = 5.025 ; deprecated standard GJ 628 (V-Ks)(M3V) = 6.11 ; deprecated standard GJ 22B => adopt (V-Ks)(M3V) = 4.60 *** [EEM 4/27/2017: there seems to be an unusually large scatter in V-Ks colors among M3V "standards". I've simply rounded the mean V-Ks color of the primary and secondary standards (4.58+-0.055) to V-Ks=4.60, and adopted that.] => adopt (U-B)(M3V) = 1.181 => adopt (V-I)(M3V) = 2.420 => adopt (V-R)(M3V) = 1.079 => adopt (R-I)(M3V) = 1.341 => adopt (V-J)(M3V) = 3.769 => adopt (V-H)(M3V) = 4.348 => adopt (H-Ks)(M3V) = 0.252 => adopt (J-H)(M3V) = 0.579 => adopt (K-W1)(M3V) = 0.122 => adopt (J-Ks)(M3V) = 0.831 => adopt (I-Ks)(M3V) = 2.180 (M3V) = 0.85 ; Beuermann06 (M3V) = 0.23 ; Beuermann06 (Bp-Rp)(M3V) = 2.1965 ; HD_225213 M3V (Bp-Rp)(M3V) = 2.2911 ; BD+16_2708 M3V (Bp-Rp)(M3V) = 2.3201 ; CD-45_5378 M3V (Bp-Rp)(M3V) = 2.3634 ; Ross_695 M3V (Bp-Rp)(M3V) = 2.3816 ; GJ_752A pri. stan. (Bp-Rp)(M3V) = 2.4008 ; BD-18_359 M3V (Bp-Rp)(M3V) = 2.4551 ; GJ_725A sec. stan. (Bp-Rp)(M3V) = 2.4574 ; GJ_436 sec. stan. (Bp-Rp)(M3V) = 2.46 ; Kiman19 (Bp-Rp)(M3V) = 2.4646 ; Ross_318 M3V (Bp-Rp)(M3V) = 2.4657 ; CD-46_11540 M3V (Bp-Rp)(M3V) = 2.4902 ; G_262-15 M3V (Bp-Rp)(M3V) = 2.4931 ; CD-37_10765A M3V (Bp-Rp)(M3V) = 2.4980 ; CD-51_6859 M3V(e) (Bp-Rp)(M3V) = 2.5041 ; GJ_109 ter. stan. (Bp-Rp)(M3V) = 2.5259 ; GJ_687 sec. stan. (Bp-Rp)(M3V) = 2.5421 ; CD-40_5404 M3V (Bp-Rp)(M3V) = 2.5466 ; BD-05_5715 M3V (Bp-Rp)(M3V) = 2.5493 ; CD-30_731 M3V (Bp-Rp)(M3V) = 2.565 ; median d<10pc N=27 (Bp-Rp)(M3V) = 2.5646 ; GJ_251 sec. stan. (Bp-Rp)(M3V) = 2.5684 ; GJ_581 exemplar (Bp-Rp)(M3V) = 2.5749 ; BD+20_2465 M3Ve (Bp-Rp)(M3V) = 2.6029 ; LP_776-46 M3V (Bp-Rp)(M3V) = 2.6109 ; L_768-119 M3V (Bp-Rp)(M3V) = 2.6245 ; BD+66_34B M3V (Bp-Rp)(M3V) = 2.6317 ; CD-44_3045B M3.0V (Bp-Rp)(M3V) = 2.6755 ; LP_399-68 M3V (Bp-Rp)(M3V) = 2.7176 ; CD-44_3045B M3.0V (Bp-Rp)(M3V) = 2.7390 ; BD-12_4523 M3V => adopt (Bp-Rp)(M3V) = 2.50 [updated 7/10/2020] (G-Rp)(M3V) = 1.1037 ; GJ_752A sec. stan. (G-Rp)(M3V) = 1.1116 ; GJ_436 sec. stan. (G-Rp)(M3V) = 1.1148 ; GJ_725A pri. stan. (G-Rp)(M3V) = 1.1227 ; GJ_109 ter. stan. (G-Rp)(M3V) = 1.140 ; d<10pc median (N=28) (G-Rp)(M3V) = 1.1416 ; GJ_687 sec. stan. (G-Rp)(M3V) = 1.1418 ; GJ_251 sec. stan. (G-Rp)(M3V) = 1.1434 ; GJ_581 exemplar (G-Rp)(M3V) = 1.144 ; color trend M0V-M9V (G-Rp)(M3V) = 1.16 ; Kiman19 => adopt (G-Rp)(M3V) = 1.13 [updated 11/18/2020] => adopt (Bp-G)(M3V) = 1.37 [updated 11/18/2020; Bp-Rp=2.50, G-Rp=1.13] (Bp-G)(M3V) = 1.31 ; Kiman19 M_G(M3V) = 9.239 ; GJ_752A pri. stan. M_G(M3V) = 9.61295 ; L 49-19 M_G(M3V) = 9.81435 ; HD 155876 M_G(M3V) = 9.8386 ; CD-37 10765A M_G(M3V) = 9.88473 ; G 262-15 M_G(M3V) = 9.97 ; Kiman19 M_G(M3V) = 10.0339 ; V* VX Ari M_G(M3V) = 10.0411 ; CD-46 11540 M_G(M3V) = 10.05 ; Mv=11.15, G-V=-1.10 M_G(M3V) = 10.06 ; trend d<20pc SIMBAD for V-Ks=4.60 M_G(M3V) = 10.1152 ; HD 173739 M_G(M3V) = 10.1212 ; HD 265866 M_G(M3V) = 10.231 ; trend d<10pc SIMBAD M_G(M3V) = 10.4146 ; BD-07 4003 M_G(M3V) = 10.4465 ; G 207-16 M_G(M3V) = 10.5145 ; exemplar GJ 3459 = LHS 1935 = LP 783-1 M_G(M3V) = 10.6234 ; BD-12 4523 M_G(M3V) = 10.6254 ; HD 239960A M_G(M3V) = 10.8428 ; CD-44 3045B M_G(M3V) = 10.8871 ; CD-44 3045A M_G(M3V) = 11.4505 ; LP 399-68 (G-V)(M3V) = -1.1585 ; GJ_436 (G-V)(M3V) = -1.1225 ; GJ_687 (G-V)(M3V) = -1.111 ; polynomial fit to SIMBAD d<25pc M dwarfs (G-V)(M3V) = -1.1025 ; GJ_109 (G-V)(M3V) = -1.095 ; G-V trend for M3V for V-Ks=4.6 (SIMBAD d<20pc) (G-V)(M3V) = -1.0828 ; GJ_251 (G-V)(M3V) = -1.0546 ; GJ_725A (G-V)(M3V) = -1.0174 ; GJ_752A => adopt (G-V)(M3V) = -1.10 [updated 11/1/2020] => adopt (G-Ks)(M3V) = 4.60 + -1.10 = 3.50 [updated 11/1/2020] (g-r)(M3V) = 1.46 ; Covey07 (r-i)(M3V) = 1.21 (+-0.16 rms) ; West08 (r-i)(M3V) = 1.212 (+-0.05 rms) ; West05 fit for (V-Ic)=2.42 => adopt (r-i)(M3V) = 1.21 [updated 12/27/2021] (i-z)(M3V) = 0.65 (+-0.08; rms) ; West08 (z-J)(M3V) = 1.37 (+-0.17 rms) ; West08 (z-J)(M3V) = 1.456 (+-0.028 rms) ; poly fit to d<100pc GCNS for G-Ks=3.50 Mv(M3V) = 10.23 ; deprecated stan. GJ 569A Mv(M3V) = 10.28 ; pri. stan. GJ 752A Mv(M3V) = 10.32 ; Wegner07 Mv(M3V) = 10.4 ; Schmidt-Kaler82 Mv(M3V) = 10.46 ; deprecated stan. GJ 22B Mv(M3V) = 10.64 ; sec. stan. GJ 436 Mv(M3V) = 10.69 ; EEM fit to Winters+2015 data Mv(M3V) = 10.71 ; deprecated stan. GJ 352 A Mv(M3V) = 10.71 ; Koen10 d<25pc median M3V Mv(M3V) = 10.84 ; Kirkpatrick94 Mv(M3V) = 10.87 ; ter. stan. GJ 687 Mv(M3V) = 10.89 ; EEM fit to Jao2016 data for V-K=4.60 Mv(M3V) = 11.15 ; M_Ks=6.55, V-K=4.60 Mv(M3V) = 11.15 ; M_G=10.05, G-V=-1.10 Mv(M3V) = 11.16 ; sec. stan. GJ 725A Mv(M3V) = 11.17 ; JohnsonApps09 calibration for V-K=4.60 Mv(M3V) = 11.18 ; median SIMBAD M3V d<25pc (N=177) Mv(M3V) = 11.22 ; tert. stan. GJ 109 Mv(M3V) = 11.23 ; Henry04 calirbation for V-K=4.60 Mv(M3V) = 11.28 ; sec. stan. GJ 251 Mv(M3V) = 11.5 ; Reid04 Mv(M3V) = 11.66 ; Henry94 Mv(M3V) = 11.94 ; deprecated stan. GJ 628 => adopt Mv(M3V) = 11.15 mag [updated 11/15/2021] (M_Ks=6.55, V-Ks=4.60) => adopt M_G(M3V) = 10.05 mag [updated 11/15/2021] (Mv=11.15, G-V=-1.10) => adopt M_Ks(M3V) = 6.55 mag [updated 11/15/2021] (Mv=11.15, V-Ks=4.60) M_Ks(M3V) = 5.83 ; pri. standard GJ 752A M_Ks(M3V) = 5.85 ; deprecated standard GJ 569A M_Ks(M3V) = 6.043 ; sec. standard GJ 436 M_Ks(M3V) = 6.15 ; deprecated standard GJ 352A M_Ks(M3V) = 6.27 ; ter. standard GJ 687 M_Ks(M3V) = 6.29 ; EEM fit to Jao+2016 data for V-Ks=4.60 M_Ks(M3V) = 6.36 ; deprecated standard GJ 22B M_Ks(M3V) = 6.50 ; V-K=4.60 => EEM fit to Winters+2015 data M_Ks(M3V) = 6.51 ; V-K=4.60 => Finch14 M_Ks(M3V) = 6.54 ; sec. standard GJ 251 M_Ks(M3V) = 6.55 ; Mv=11.15, V-Ks=4.60 M_Ks(M3V) = 6.57 ; V-K=4.60 => JohnsonApps2009 calibration [Fe/H]=0.00 M_Ks(M3V) = 6.58 ; ter. standard GJ 109 M_Ks(M3V) = 6.63 ; V-K=4.60 => Henry04 calibration M_Ks(M3V) = 6.69 ; sec. standard GJ 725A M_Ks(M3V) = 6.91 ; deprecated standard GJ 628 M_Ks(M3V) = 6.97 ; exemplar GJ 3459 = LHS 1935 = LP 783-1 Teff(M3V) = 3231 K ; mean photometric Teff Teff(M3V) = 3276 K ; median Teff for 48 Teffs for M3V stars (EEM) Teff(M3V) = 3300 K ; Rajpurohit13 (N=9) Teff(M3V) = 3300 K ; Johnson66 Teff(M3V) = 3316 +- 12 K ; Pecaut13 (pri. stan. GJ 752A) Teff(M3V) = 3320 +- 14 K ; Pecaut13 (ter. stan. GJ 687) Teff(M3V) = 3332 K ; Morrell19 for stars w/i +-0.05 mag of M_Ks=6.50 Teff(M3V) = 3350 K ; Bessell91 "old disk" Teff(M3V) = 3373 K ; RojasAyala12(mean N=29 M3V stars) Teff(M3V) = 3377 +- 18 K ; Pecaut13 (sec. stan. GJ 436) Teff(M3V) = 3382 K ; Rajpurohit18(mean for N=38 M3Vs) Teff(M3V) = 3390 K ; ter. stan. GJ 109 Teff(M3V) = 3402 K ; exemplar GJ 3459 = LHS 1935 = LP 783-1 (peak M_G) Teff(M3V) = 3405 K ; sec. stan. GJ 251 Teff(M3V) = 3410 K ; Rad=0.367Rsun using Mann15 calib for M_Ks=6.55, [Fe/H]=0.0 Teff(M3V) = 3412 +- 54 K ; Boyajian12b (N=3) Teff(M3V) = 3415 K ; smooth Teff(SpT) trend Teff(M3V) = 3416 +- 54 K ; non-standard GJ 436 (vonBraun12) Teff(M3V) = 3423 +- 62 K ; Lepine12 Teff(M3V) = 3427 K ; empirical L-R relation, for logL=-1.788 Teff(M3V) = 3451 K ; sec. stan. GJ 725A Teff(M3V) = 3456 K ; Passegger18 median Teff for CARMENES M3.0Vs(N=48) Teff(M3V) = 3470 K ; Schmidt-Kaler82 Teff(M3V) = 3473 K ; Boyajian12 calibration V-K=4.60, [Fe/H]=0.0 Teff(M3V) = 3477 K ; sec. stan. GJ 436 Teff(M3V) = 3489 K ; ter. stan. GJ 687 Teff(M3V) = 3493 K ; deprecated standard GJ 860A median Teff Teff(M3V) = 3558 K ; pri. stan. GJ 752A Teff(M3V) = 3636 K ; deprecated standard GJ 569A median Teff => adopt Teff(M3V) = 3430 K (logT = 3.535) [updated 7/17/2020] BCv(M3V) = -1.686 mag ; EEM fit to Casagrande08 data for Teff=3400K BCv(M3V) = -1.847 mag ; deprecated standard GJ 569A (see notes) BCv(M3V) = -1.872 mag ; non-standard GJ 436 (Pecaut13) BCv(M3V) = -1.886 mag ; Pecaut13(V-K=4.60) BCv(M3V) = -1.897 +- 0.019 mag ; pri. stan. GJ 725A (Pecaut13) BCv(M3V) = -1.930 mag ; Mann15(V-J=3.769) BCv(M3V) = -1.949 mag ; ter. stan. GJ 687 (Pecaut13) BCv(M3V) = -1.962 mag ; pri. stan. GJ 752A (see notes) BCv(M3V) = -1.93 mag ; BC_K = 2.67, V-Ks = 4.60 BCv(M3V) = -1.983 mag ; Casagrande18(Teff=3420K,logg=4.5) BCv(M3V) = -2.012 mag ; deprecated standard GJ 352 A BCv(M3V) = -2.02 mag ; Schmidt-Kaler82(BCv=-2.15 + 0.13 offset) BCv(M3V) = -2.03 mag ; Bessell91("old disk"; BCv = (V-I)-BC_I) BCv(M3V) = -2.033 mag ; exemplar GJ 581 = Wolf 562 BCv(M3V) = -2.039 mag ; sec. stan. GJ 725A (see notes below) BCv(M3V) = -2.108 mag ; ter. stan. GJ 109 (see notes below) BCv(M3V) = -2.248 mag ; sec. stan. GJ 251 (see notes below) BCv(M3V) = -2.509 mag ; deprecated stan. GJ 628 (see notes below) BCv(M3V) = -2.672 mag ; Flower96(Teff=3400K) => adopt BCv(M3V) = -1.93 mag [updated 11/3/2019, BC_K=2.67, V-K=4.60] BC_K(M3V) = 2.433 ; sec. stan. GJ 725A BC_K(M3V) = 2.485 ; pri. stan. GJ 752A BC_K(M3V) = 2.497 ; sec. stan. GJ 251 BC_K(M3V) = 2.499 ; ter. stan. GJ 687 BC_K(M3V) = 2.516 ; deprecated standard GJ 628 BC_K(M3V) = 2.526 ; tert. stan. GJ 109 BC_K(M3V) = 2.533 ; deprecated standard GJ 569A BC_K(M3V) = 2.543 ; deprecated standard GJ 352A BC_K(M3V) = 2.550 ; sec. stan. GJ 436 BC_K(M3V) = 2.575 +- 0.024 ; sec. stan. GJ 725A (Pecaut13) [mbol = 7.007+-0.014, Ks=4.432+-0.020] BC_K(M3V) = 2.617 ; Casagrande18(BCv=-1.983,Teff=3420K) w/V-Ks=4.60 BC_K(M3V) = 2.625 ; Leggett01 polynomial for J-K=0.831 BC_K(M3V) = 2.654 ; Leggett01 polynomial for I-K=2.180 BC_Ks(M3V)= 2.664 ; Morrell19 trend for G-Ks=3.50 BC_K(M3V) = 2.678 ; Mann15(V-J=3.769) BC_K(M3V) = 2.683 +- 0.023 ; ter. stan. GJ 687 (Pecaut13) [mbol = 7.231+-0.010, Ks=4.548+-0.021] BC_Ks(M3V)= 2.702 ; exemplar GJ 581 = Wolf 562 BC_K(M3V) = 2.705 +- 0.019 ; non-standard GJ 436 (Pecaut13) [mbol = 8.778+-0.011, Ks=6.073+-0.016] BC_K(M3V) = 2.714 ; Pecaut13(V-K=4.60) => adopt BC_K(M3V) = 2.66 [updated 11/15/2021] logL(M3V) = -1.43 dex ; pri. stan. GJ 752A logL(M3V) = -1.46 dex ; deprecated stan. GJ 569A logL(M3V) = -1.54 dex ; sec. stan. GJ 436 logL(M3V) = -1.58 dex ; ter. stan. GJ 687 logL(M3V) = -1.75 dex ; sec. stan. GJ 725A logL(M3V) = -1.76 dex ; ter. stan. GJ 109 logL(M3V) = -1.770 dex ; Morrell19 trend for logL for M_Ks=6.50 logL(M3V) = -1.788 dex ; M_Ks=6.55 & BC_Ks=2.66 => Mbol=9.210 logL(M3V) = -1.88 dex ; deprecated stan. GJ 628 => adopt logL(M3V) = -1.788 dex [updated 11/15/2021] => adopt Mbol(M3V) = 9.210 mag [updated 11/15/2021] Mass(M3V) = 0.214+-0.001 Msun ; GJ747A (Benedict16) Mass(M3V) = 0.268+-0.020 Msun ; GJ860A (Benedict16) Mass(M3V) = 0.305 Msun ; exemplar GJ 3459 = LHS 1935 = LP 783-1 Mass(M3V) = 0.31 Msun ; deprecated standard GJ 22B (MSC) Mass(M3V) = 0.330 Msun ; Benedict16 calib. for Mv=11.10 Mass(M3V) = 0.35 Msun ; Mv=11.16 => HenryMcCarthy93 calibration Mass(M3V) = 0.355 Msun ; M_Ks=6.55 => Mann18 calibration Mass(M3V) = 0.390 Msun ; M_Ks=6.55 => Benedict16 calibration Mass(M3V) = 0.398 Msun ; Eker18 calibration for logL=-1.788 Mass(M3V) = 0.43 Msun ; EEM logL vs. Mass fit for binaries (logL=-1.77) Mass(M3V) = 0.432 Msun ; Eker15 calibration for logL=-1.788 Mass(M3V) = 0.507+0.071-0.062 ; non-stan. GJ 436 (vonBraun12) Mass(M3V) = 0.54 Msun ; EEM Mv vs. Mass fit for binaries (Mv=11.17) => adopt Mass(M3V) = 0.36 Msun [updated 7/17/2020] Rad(M3V) = 0.322+-0.005 Rsun ; exemplar GJ 581 = Wolf 562 Rad(M3V) = 0.356+-0.004 Rsun ; sec. stan. GJ 725A = LHS 58 (Yee17) Rad(M3V) = 0.358+-0.013 Rsun ; sec. stan. GJ 251 = HD 265866 (Yee17) Rad(M3V) = 0.36146 Rsun ; logL=-1.788, Teff=3430K Rad(M3V) = 0.364+-0.014 Rsun ; ter. stan. GJ 109 = LHS 1439 (Yee17) Rad(M3V) = 0.367 Rsun ; Mann15 trend M_Ks=6.55, [Fe/H]=0.0 Rad(M3V) = 0.392 Rsun ; Rabus19 trend for Teff=3440K Rad(M3V) = 0.4097+-0.0075 Rsun ; Boyajian12b (N=3) Rad(M3V) = 0.418+-0.007 Rsun ; sec. stan. GJ 687 = HIP 86162 (Yee17) Rad(M3V) = 0.455+-0.018 Rsun ; sec. stan. GJ 436 (Yee17) Rad(M3V) = 0.474+-0.016 Rsun ; pri. stan. GJ 752A (Yee17) => adopt Rad(M3V) = 0.361 Rsun [updated 12/28/2020] # No Standards Houk75 and Keenan85 do not list a M3V standard. Houk75 lists no standards later than M2V. # Primary Standards GJ 752A = HD 180617 = LHS 473 = Wolf 1055 = V1428 Aql = HIP 94761 (J1916+0510) M1V: Newton14(near-IR for GJ752AB) M2III: Houk99(q=3) M2.5V: Hawley97,Lepine13 M2.6V: Mann15 M3-V: Keenan85,Keenan88 *M3V: Lee47(M3),Joy74,Boeshaar76(stan),Boeshaar85(dM3),Kirkpatrick91(pri),Kirkpatrick94,Henry94,Boeshaar94,Henry02,Kirkpatrick(GrayCorbally09),Kirkpatrick10(opt.,near-IR),Gaidos14(M3) M3.5V: JM53 Continuity as M3V standard from Boeshaar, Kirkpatrick, & Henry, and Kirkpatrick considers this the primary standard. Unfortunately 3 expert classifiers have it +-0.5 subtype different from M3V (e.g. JohnsonMorgan53, Keenan88, Hawley97), and Newton15 considers it M1V(!) in the near-IR, but it appears to be the best available. It is also a bit bluer and brighter than all the other M3V "standards", so it might be best considered M3-V? Companion GJ 752B (M8V standard) is ~75" away (Lepine07). V=9.12(HIP), V=9.115(Koen10), B-V=1.464+-0.005(HIP), B-V=1.515(Koen10), U-B=1.138(Koen10), V-Ic=2.333(Koen10), V-I=2.32+-0.00(HIP), V-Rc=1.039(Koen10), R-I=1.29(Delfosse98), J=5.583+-0.030(2MASS), H=4.929+-0.027, Ks=4.673+-0.020(2MASS), V-J=3.537(HIP & 2MASS), (V-Ks)=4.447(HIP & 2MASS). mbol = 7.158+-0.022 using 2MASS JHKs and Casagrande08 calibration => BCv = mbol - V = 7.158 - 9.12 = -1.962, BC_Ks = 2.485. Plx = 170.36+-1.00 mas => Mv = 10.28, M_Ks = 5.83+-0.02, Mbol = 8.32+-0.03, logL = -1.43+-0.01. Teffs: 3425K(Stelzer13), 3510K(Houdebine16), 3500K(Rajopurohit18), 3500K(Lepine13), 3557K(Gaidos14), 3558+-60K(Mann15#1), 3559K(Muirhead18), 3619+-34K(Mann15#2), 3680+-70K(Gaidos14), 3789K(RojasAyala12) => median Teff = 3558 K. R=0.457+-0.010Rsun(Mann15#2), R=0.474+-0.016Rsun(Mann15#1), M=0.475+-0.047Msun(Mann15#1), M=0.488+-0.011Msun(Mann15#2), [Fe/H]=0.10+-0.08(Mann15), [Fe/H]=0.06+-0.12(Newton14). Rad=0.474+-0.016Rsun(Yee17). GaiaDR2: plx=169.1590+-0.0520, M_G=8.0976+-0.0011, E(BR/RP)=1.403, Bp-Rp=2.3816, Bp-G=1.2779, G-Rp=1.1037. M_G=9.239+-0.001, M_Ks=5.814+-0.020, Mv=10.26. # Secondary Standards GJ 251 = HD 265866 = Wolf 294 = G 087-012 = LHS 1879 = HIP 33226 *M3V: Lee47(M3),Kirkpatrick91(pri),Henry94,Hawley97,Henry02,Hawley02(stan),Gaidos14(M3),Newton14(near-IR) M3.2: Mann15 M3.5V: Joy74,Boeshaar76(stan) M4V: Stephenson86,Jenkins09 M5: Roth51,Vyssotsky56 Nice agreement as M3V by Kirkpatrick, Henry, & Hawley, however I knock it down to secondary due to Boeshaar's M3.5V classification. B=11.609+-0.02(UCAC4), V=9.89(HIP), V=9.938(Hauck90), V=9.938+-0.063(Mermilliod91), V=10.01(Gliese91), V=10.02(Weis93), V=10.03(Reid02), V=10.034+-0.08(UCAC4), V=10.170+-0.08(Droege07) B-V=1.57(Weis93), B-V=1.585+-0.013(Mermilliod91), B-V=1.580+-0.040(HIP), U-B=1.218+-0.015(Mermilliod91), U-B=1.21(Weis93), V-R=1.29(Weis93), R-I=1.11(Weis93), V-I=2.56+-0.09(HIP), J=6.104+-0.024(2MASS), H=5.526+-0.016(2MASS), Ks=5.275+-0.023(2MASS). Using Casagrande08 calibrations and 2MASS JHK photometry, mbol = 7.772+-0.014. Hence BCv = mbol - V = 7.772 - 10.02 = -2.248, BC_K = mbol - Ks = 7.772 - 5.275 = 2.497. Adopting Vmag from Weis93 (close to median of published values), V-Ks = 10.02 - 5.275 = 4.745. Plx = 179.01 +- 1.60 mas (vanLeeuwen07) => Mv = 11.28, M_Ks = 6.54, Mbol = 9.04, logL=-1.72. Mass = 0.372+-0.002 Msun(Jenkins09). Teffs: 3318K(Stelzer13), 3389+-68K(Gaidos14), 3400K(Frasca09), 3400K(Rajopurohit18) 3401K(Gaidos14), 3410+-100K(Houdebine16), 3448+-60K(Mann15#1), 3477+-11K(Wu11), 3487+-31K(Mann15#2), 3500K(Rojas-Ayala12) => adopt Teff = 3405K. [Fe/H]=-0.02+-0.08(Mann15). R=0.349+-0.008Rsun(Mann15), M=0.365+-0.009Msun(Mann15). Rad=0.358+-0.013Rsun(Yee17). GJ 436 = Ross 905 = HIP 57087 = DO 14469 = G 120-068 = LHS 310 = NLTT 28288 M0: Lee47 M2V: Vyssotsky56,Stephenson86 M2.5V: Hawley97,Reid04,Terrien15,Alonso-Floriano15 *M3V: Boeshaar76,Bidelman85,Kirkpatrick91(pri),Henry02,RojasAyala12,Lepine13,Newton14,Gaidos14,Mann15 M3.5V: Joy74 Has hot Neptune transiting companion GJ 436b. B=12.179+-0.01(UCAC4), V=10.613+-0.01(UCAC4), V=10.65(Weis93), V=10.67(HIP)*, V=10.68(vanAltena95), V=10.730+-0.090(Mermilliod91), B-V=1.467+-0.094(Mermilliod91), B-V=1.52(vanAltena95), B-V=1.493+-0.022(HIP), U-B=1.01(vanAltena95), U-B=1.230(Mermilliod91), V-I=2.02+-0.13(HIP), J=6.900+-0.024(2MASS), H=6.319+-0.023(2MASS), Ks=6.073+-0.016(2MASS). Adopting HIP Vmag: V-Ks = 10.67 - 6.073 = 4.597. mbol = 8.623+-0.011 calculated using 2MASS JHKs and Casagrande08 calibration. Plx = 98.61+-2.33(vanLeeuwen07) => Mv = 10.64, M_Ks = 6.043, Mbol = 8.593+-0.052, logL = -1.54+-0.02. BCv = mbol - V = 8.623 - 10.67 = -2.047, BC_Ks = mbol - Ks = 8.623 - 6.073 = Teffs: 3253K(V-K=>Casagrande08 calib.), 3410K(Morales08), 3416+-53K(Boyajian12), 3469+-17K(RojasAyala12), 3477+-81K(Newton15#2), 3479+-60K(Mann15#1), 3520+-66K(Newton15#1), 3584+-39K(Mann15#2), 4002K(Butler06,using Flower96 B-V calib.) => adopt Teff = 3477K. Sozetti06 lists probability 89% thin disk, 11% thick disk star. logL=-1.59+-0.05(Newton15). [Fe/H]=0.00(Newton15#1), [Fe/H]=-0.04(Newton15#2). M=0.447+-0.015Msun(Mann15), R=0.420+-0.014Rsun(Mann15). GJ 725A = LHS 58 = HD 173739 = DO 36465 = ADS 11632 A = BD+59_1915A = G 227-46 = G 229-13 = HIP 91768 M2V: Newton14(near-IR) M2/5V: Vyssotsky46 *M3V: Turnshek85,Bidelman85,Anosova87,Kirkpatrick91(pri),Henry94,Hawley97,Henry02,Geballe02,Henry(RECONS),Mann15(M3.0) M4V: Lee47,Joy74 Kirkpatrick, Henry, Hawley agree on M3V. Kirkpatrick in DwarfArchives lists the GJ 725 system as M3V+M3.5V and cites Kirkpatrick91. AB have separation 13". V=8.904+-0.013(Mermilliod91), V=8.94(HIP), B-V=1.537+-0.009(Mermilliod91), B-V=1.504+-0.008(HIP), U-B=1.104+-0.025(Mermilliod91), J=5.189+-0.017(2MASS,Qflg='E'), H=4.741+-0.036(2MASS,Qflg='E'), Ks = 4.432+-0.020(2MASS). Using Casagrande08 relations with JHKs photometry: mbol = 6.865+-0.056 (note: mbol = 6.857 just from Ks magnitude, so it should be OK). BCv = mbol - V = 6.865 - 8.904 = -2.039, BC_Ks = mbol - Ks = 6.865 - 4.432 = 2.433. (V-Ks) = 8.904 - 4.432 = 4.472. vanLeeuwen07 derives parallaxes for GJ 725 A and B: plx(A)=280.18+-2.18mas, plx(B)=289.48+-3.21 => weighted mean parallax = 283.12 +- 1.80 mas => D = 3.53+-0.02 pc. Mv(A) = 11.16+-0.02, M_Ks(A) = 6.69 +- 0.02, Mbol(A) = 9.10+-0.06, logL = -1.75. Teffs: 3276K(Jenkins09), 3318K(Stelzer13), 3375+-81K(Newton15#2), 3400K(Frasca09), 3417+-17K(Newton15#1), 3441K(Mann15#1), 3450K(Kirkpatrick93), 3451K(Cenarro01), 3481+-10K(Wu11), 3517+-22K(Mann15#2), 3620K(Zboril98), 3680K(RojasAyala12) => median Teff = 3445K. R=0.351+-0.013Rsun(Mann15#1), R=0.334+-0.006Rsun(Mann15#2), R=0.352+-0.030Rsun(Newton15#2), R=0.356+-0.004Rsun(Newton15#1), M=0.334+-0.033Msun(Mann15#1), M=0.349+-0.008Msun(Mann15#2), logL=-1.82+-0.05(Newton15#2), logL=-1.8033+-0.0052(Newton15#1), [Fe/H]=-0.23+-0.08(Mann15), [Fe/H]=-0.60+-0.15(Newton14). Boyajian12 lists tetLD=0.937+-0.008mas. Boyajian12+HIP2(wt.mean) => Rad=0.356Rsun. Rad=0.356+-0.004Rsun(Yee17). # Tertiary Standard GJ 687 = HIP 86162 = BD+68_946 = DO 35853 = G 240-063 = LFT 1364 = LHS 450 M2: Lee47 *M3V: Adams35,Luyten79,Bidelman85,Kirkpatrick94,Henry94,Hawley97,Henry02,Dieterich12,Reiners12,Lepine13,Gaidos14,Newton14(near-IR),Alonso-Floriano15 M3.5V: JM53(non-stan.) M4V: Adams26,Joy74 M5V: Vyssotsky52 WDS lists BC component at separation 302" away, however it is not clear whether it is physical. V=9.15(HIP), V=9.17(Weis93), B-V=1.505+-0.013(HIP), B-V=1.47(Weis93), V-R=1.26(Weis93), R-I=1.11(Weis93), V-I=2.11+-0.10(HIP). J=5.335+-0.021(2MASS), H = 4.766+-0.033(2MASS,flag='E'), Ks = 4.548+-0.021(2MASS). Hence V-Ks = 9.15 - 4.548 = 4.602. Using Casagrande08 relations, the 2MASS JHK photometry is consistent with mbol = 6.967 +- 0.020, hence BCv = mbol - V = 6.967 - 9.15 = -2.183, BC_Ks = mbol - Ks = 2.419. Plx = 220.84+-0.94 mas(van Leeuwen07) => Mv = 10.87, M_Ks = 6.27, Mbol = 8.69+-0.02, logL = -1.58+-0.01. Teffs: 3237K(Jenkins09), 3395K(RojasAyalas12), 3583K(Soubiran08), 3748K(Masana06) => median Teff = 3489 K. Radius = 0.372+-0.008 Rsun(Masana06). BC_K = 2.499+-0.054(Masana06). BCv = -2.103+-0.072(Masana06). Nidever02 quotes GJ 687 as being a very stable RV star (rms < 100 m/s over ~3 years), so unlikely to be an unresolved binary star. [Fe/H]=-0.14+-0.12(Newton14). Boyajian12 lists tetLD=0.859+-0.014mas. plx=219.7807+-0.0324mas(GaiaDR2). Boyajian12+GaiaDR2 => Rad=0.420Rsun. GJ 109 = LHS 1439 = NLTT 8817 = LTT 10844 = HIP 12781 = VX Ari = Ross 556 (J0233+2455) M2V: Vyssotsky56,Stephenson86 *M3V: Lee47,Bidelman85,Henry94,Reid15,Henry02,Lurie13(M3),Newton14,Gaidos14(M3),Mann15(M3) M3.5V: Joy74 M4: Luyten45 Not considered a standard in Kirkpatrick91, but has been ubiquitously considered M3V since Henr94. In DwarfArchives, Kirkpatrick cites Henry94. V=10.595+-0.009(Mermilliod91), B-V=1.550+-0.000(Mermilliod91), U-B=1.110(Mermilliod91), J=6.752+-0.018(2MASS), H=6.197+-0.017(2MASS), Ks=5.961+-0.021(2MASS). (V-Ks) = 10.595 - 5.961 = 4.634. Plx = 133.16+-2.26 mas (vanLeeuwen07) => Mv = 11.22+-0.04, M_Ks = 6.58+-0.04. Using Casagrande08 calibration and 2MASS JHK photometry => mbol = 8.487+-0.021 => Mbol = 9.11 => logL = -1.75 => BCv = mbol - V = 8.487 - 10.595 = -2.108, BC_K = mbol - Ks = 2.526. Teffs: 3228K(Jenkins09), 3238K(V-K=>Casagrande08), 3390K(Morales08), 3462K(Koleva12), 3487K(V-K=>Mozurkewich03) => median Teff = 3390K. Rad=0.364+-0.014Rsun(Yee17). # Deprecated Standards GJ 860A = Kruger 60A = HD 239960 = BD+56_2783 = DO Cep (J2227+5741) *M3V: Adams26,Neckel58(M3),Christy69,Bidelman85,Kirkpatrick92PhD,Kirkpatrick94,Henry94,Hawley97,Henry02,Tamazian06,Kirkpatrick12(Kirkpatrick92), Royas-Ayala12(K-band,jointAB) M3.5V: Joy74,KeenanMcNeil76(stan) M5: Nassau54 Close binary (3.5"), may not be best choice of standard? Only one of the Adams26 (1926ApJ....64..225A) "M3" stars that survives as modern M3V standard. KeenanMcNeil76 type differs by 0.5 subtype from most recent classifications by Henry and Hawley. Kirkpatrick12 cites Kirkpatrick92 (PhD thesis) and calls the GJ 860 AB system as M3V + M4V. Binary: 3.4" binary with V=11.30 star GJ 860B (see "M4V" file). V=9.85(Gliese91), V=9.81(Tycho), B-V=1.62(Gliese91), U-B=1.23(Gliese91). HIP V (V(AB)=9.59), B-V, and V-I are for unresolved GJ 860AB, and GJ 860 is unresolved in 2MASS. V(AB)=9.587+-0.015(Mermilliod91). Gliese91 resolves as V(A)=9.85, V(B)=11.30, i.e. del(V)=1.45. Significantly redder in B-V than GJ752A (B-V = 1.62 vs. 1.464, respectively). GaiaDR3 resolves G(A)=8.669386, G(B)=9.980165, del(G)=1.31. HIP CCDM lists Hp(A)=9.795+-0.012, Hp(B)=11.406+-0.050 => delta(Hp)=1.611+-0.051. Adopting delta(V)=1.45 from Gliese91, and adopting V(AB)=9.587+-0.015 from Mermillid91, then V(A)=9.841, V(B)=11.291, i.e. within 0.01 mag of Gliese91. WDS lists mag(A)=9.930, mag(B)=11.41, which looks suspiciously close to V. plx=249.94+-1.87mas(vanLeeuwen07). Teffs: 3152K(Jenkins09), 3464K(RojasAyala12,for AB), 3521K(Wright11), 3620K(Zboril98) =>> median Teff = 3493K. [Fe/H]=-0.25(Zboril98). HRD position: V=9.841, plx=249.94 => Mv=11.83, and adopting BCv=-1.93 => Mbol=9.90, logL=-2.064. GJ 22B = BD+66_34B = LHS 115 = HIP 2552 B = CCDM 00325+6714 B = 2MASS J00322979+6714043 *M3V: McCarthy91,Kirkpatrick91(sec),Kirkpatrick94,Hawley97,Henry02,Royas-Ayala12(K-band) M3.5: Bidelman85 I only demote this standard star based on its close binarity (4"). Few classifications, but agreement among Kirkpatrick, Henry, & Hawley papers. According to WDS the GJ 22 binary was 2.3" separation in 1923, but 4.0" in 2010, and lists mag1=10.62, mag2=12.20 (delta(mag)=1.58). 2MASS photometry is relatively poor. J=7.172+-0.085(2MASS), H=6.538+-0.090(2MASS), Ks=6.377+-0.061(2MASS). Interestingly, the 2MASS delta(J)=0.35, delta(K)=0.34 but ~2 mags at V. Mermilliod91 UBV photometry is unresolved for AB: V(ABC)=10.312+-0.025, B-V(ABC)=1.501+-0.045, U-B(ABC)=1.160. V(AB)=10.27(HIP). Tokovinin MSC: mass(B) = 0.31 Msun. DeltaMagnitudes (band,magA, magB, diff): Lepine05(V, 10.49, 12.19, 1.70), MSC(V, 10.38,12.40, 2.02), Heintz93(V, 10.5, 12.4, 1.9), CCDM(Hp, 10.564+-0.018, 12.197+-0.080, 1.633+-0.082). Adopting delta(V)=2.02 from Tokovinin MSC, and Mermilliod91 photometry, then V(A) = 10.47, V(B)=12.49. Hence, V-Ks = 12.49 - 6.377 = 6.11, and V-J = 12.49 - 7.172 = 5.32. This seems way too red for M3V? 2MASS counterpart confirmed by Stauffer10 (Ks=6.377). Plx = 99.35+-2.17 mas (vanLeeuwen07) => Mv = 10.46, M_Ks = 6.36+-0.08. GJ 352 AB = LHS 2151 = LFT 656 = HIP 46706 M2V: Vyssotsky43 M2.5V: Walker83 *M3V: Bidelman85(M3), Stephenson86, Kirkpatrick91(pri),Hawley97(for A only),Henry02(M3VJ) M3+V: Boeshaar76 Unresolved binary: WDS reports sep 0.6" (epoch 1942) and 0.70" (epoch 2010), mag1=10.74, mag2=10.94. Hipparcos reports delta(Hp)=0.20+-0.04 mag. V(AB) = 10.06(HIP), V(AB) = 10.054+-0.015(Mermilliod91), B-V=1.539+-0.012(Mermilliod91), 1.545+-0.018(HIP), V-I=2.39+-0.01(HIP), U-B=1.156+-0.022(Mermilliod91), J=6.361+-0.020(2MASS), H=5.755+-0.029(2MASS), Ks=5.511+-0.020(2MASS). Worley01 catalog reports observations from Henry93 - delta magnitudes in near-IR: delta(K) = 0.23, delta(H) = 0.26, delta(J) = 0.33. Splitting the 2MASS photometry using these delta(magnitudes), I derive J(A) = 6.961, J(B) = 7.291, H(A) = 6.385, H(B) = 6.645, Ks(A) = 6.155, Ks(B) = 6.385. Assuming delta(V) = 0.20+-0.04, then V(A) = 10.71+-0.02, V(B) = 10.91 +- 0.05. Unresolved V-Ks = 10.054 - 5.511 = 4.543 (Mermilliod91,2MASS). Resolved: V(A) - Ks(A) = 10.71 - 6.155 = 4.56, V(B) - Ks(B) = 10.91 - 6.385 = 4.53 Plx = 99.88+-3.60(vanLeeuwen07) => Mv(A) = 10.71+-0.08, Mv(B) = 10.91+-0.09, M_Ks(A) = 6.15, M_Ks(B) = 6.38. Using resolved JHK photometry for A, and Casagrande08 relations, I derive: mbol(A) = 8.698+-0.015, hence BCv = mbol - V = 8.698 - 10.71 = -2.012, BC_Ks = 8.698 - 6.155 = 2.543. GJ 569A = CE Boo = G 136-28 = NLTT 38745 = HIP 72944 M0V: Vyssotsky46 M1:V: Alonso-Floriano15 M2Ve: Lee47(M2),Joy74,Hawley97,Lepine13,Gaidos14(M2) M2.5V: HenryKirkpatrick90 *M3V: Stephenson86,Henry90,Kirkpatrick91(sec),Newton14(near-IR) Surprisingly wide range of types among modern classifiers (M1-M3 over the past 3 decades). Unfortunately only Kirkpatrick91 considered it a M3V standard, and Hawley called it M2. It seems a bit hotter and bluer than the other M3V standards. Gl 569Bab system is 5.72" away, which is a M8.5V+M9.0V pair. U = 12.86(Koen10), B = 11.686(Koen10), V=10.150(Koen10), V = 10.20(Gliese91, Mermilliod91), B-V=1.480(Mermilliod91, Gliese91), U-B = 1.150(Mermilliod91, Gliese91), R = 9.116(Koen10), I = 7.872(Koen10), J = 6.693(Koen10), J = 6.633+-0.023(2MASS), H = 5.922(Koen10), H=5.990+-0.021(2MASS), K = 5.771(Koen10), Ks = 5.770+-0.018(2MASS). (V-Ks) = 10.15 - 5.77 = 4.38. 2MASS JHKs photometry and Casagrande08 relations yields: mbol = 8.303+-0.008. Hence BCv = mbol - V = 8.303 - 10.15 = -1.847, BC_Ks = mbol - Ks = 8.303 - 5.770 = 2.533. Plx = 103.59 +- 1.72 mas (vanLeeuwen07) => Mv = 10.23, M_Ks = 5.85+-0.04, Mbol = 8.38 +- 0.04, logL = -1.46+-0.02. Mass: 0.48 Msun(Donati08), 0.499+-0.028(Jenkins09). Teffs: 3345K(Jenkins09), 3372+-12K(Rabus19), 3540K(Morales08), 3732K(Wright11), 3780K(Zboril98) => median Teff = 3636K. Madsen02 includes GJ 569 (HIP 72944) in the Ursa Major cluster. Nidever02 finds GJ 569A to be RV stable to <100 m/s over ~4 years. Rabus19 reports: tetLD=0.661+-0.014mas, fbol=(1.882+-0.068)e-8 erg/s/cm2, Rad = 0.306+-0.007Rsun, Teff=3372+-12K. GJ 628 = Wolf 1061 = V2306 Oph = LHS 419 = BD-12_4523 = HIP 80824 *M3.0V: Henry94,Kirkpatrick94,Henry02,Royas-Ayala12(K-band) M3.5V: Hawley97 M4: Gaidos14 M4.5V: Joy74,Walker83 M5V: Adams26 I would prefer to see better agreement among the published types for a standard star, and the star does appear to be redder/cooler than the majority of other M3V standards. The Washington Visual Double Star Catalog lists components "B" through "H", but these appear to be very faint objects with magnitude 18.8 to 21.7 found by Lafreniere, and it does not appear that any are physical companions. V=10.10(HIP), V=10.100+-0.013(Mermilliod91), B-V=1.595+-0.013(Mermilliod91), B-V=1.604+-0.035(HIP), U-B=1.183+-0.020(Mermilliod91), J=5.950+-0.024(2MASS), H = 5.373+-0.040(2MASS), Ks=5.075+-0.024(2MASS). Combining 2MASS JHKs photometry with Casagrande08 relations, I derive mbol = 7.591+-0.024, and hence BCv = mbol - V = 7.591 - 10.100 = -2.509, BC_Ks = 7.591 - 5.075 = 2.516. Plx = 232.98+-1.60mas(VanLeeuwen07) => Mv = 11.94+-0.02, M_Ks = 6.91+-0.03, Mbol = 9.43+-0.03, logL = -1.88+-0.01. Teffs: 3097K(Jenkins09), 3380K(RojasAyala12), 3570K(Zboril98) => median Teff = 3380K. GJ 661 AB = HD 155876 = DO 35634 *M3VJ: Henry94(J),Henry02(J),Gray03(M3V) M3.5V: Hawley97(just for A) M4V: Adams26,Lee47(M4),Joy74 Unresolved binary. G 5-43 = LHS 1554 = Gl 143.3 = CNS3 633 = 2MASS J03314712+1419194 M2: Hawley97,Gaidos14 *M2.5: Lepine13 M3V: KeenanMcNeil76(stan) sdM3: Eggen65 Was the M3V standard according to KeenanMcNeil76, but apparently abandoned after that (Keenan80 and later editions didn't list it as a standard, and Boeshaar, Kirkpatrick, Henry, and others didn't use it as a standard either). Appears to have fallen into disuse as a standard. Gaidos and Lepine subsequently estimated earlier types. Gaidos14 estimates metallicity [Fe/H]=-0.05+-0.12 dex. Hawley estimates space velocity: U,V,W = +45,-52,-19 which suggests an old star. I estimate P(thin) = 79%, P(thick)=21%, P(halo)=0.15%. So this is likely to be a ~solar composition, old thin disk star. V=12.263(Koen10), B-V=1.583(Koen10), U-B=1.279(Koen10), V-Rc=1.053(Koen10), V-Ic=2.310(Koen10). GJ 388 = AD Leo = Gam Leo C = BD+20_2465 = StKM 2-626 M2V: Stephenson86 *M3V: Kirkpatrick94,Henry94,Hawley97,Newton14(stan) M3.5V: Joy74(M3Ve),Bidelman85(M3.5) M4Vae: Keenan85(M4V),Keenan99 M4.5:V: Johnson53 M5Ve: Vyssotsky56 Poor agreement among classifications, anywhere from M2 to M5. Henry94 - using Kirkpatrick91 standards - class it M3V. In Jacoby84 atlas as M4.5eV. Malkov12 lists it as a binary with period 26.5 years, a=0.1109", e=0.60. Leggett96 derives: flux = 3.12e-11 W/m^2, logL=-1.64, mbol=7.29, Mbol=8.85, BCv=-2.03, BC_K=2.68. V=9.421+-0.017(Mermilliod91), B-V=1.544+-0.009(Mermilliod91), U-B=1.075+-0.019(Mermilliod91), J=5.449+-0.027(2MASS), H=4.843+-0.020(2MASS,flag=E), Ks=4.593+-0.017(2MASS). V-Ks=4.828(Mermilliod91,2MASS). # Exemplars GJ 581 = Wolf 562 = BD-7 4003 M2V: Newton14(near-IR) M2.5V: Henry94,Henry02 *M3V: Bidelman85(M3),Stephenson86,Hawley97,Reiners12,Dieterich12,Lurie14 M3.2: Mann15 M3.5V: Walker83 M4V: Joy74 Henry group changed type from M2.5V (Henry94,Henry02) to M3V (Dieterich12,Lurie14), and since others have classified it anywhere between M2 to M3.2, I've dropped it as an M2.5V standard but adopted it as a M3V exemplar. Exoplanet host star. Teff=3395+-60K(Mann15), [Fe/H]=-0.15+-0.08(Mann15), -0.07+-0.12(Newton14). Mermilliod91: V=10.572+-0.009, B-V=1.601+-0.009, U-B=1.205+-0.013. Kmag=5.837+-0.023(2MASS). Rabus19 reports: tetLD=0.476+-0.007mas, fbol=(0.967+-0.039)e-8 erg/s/cm2 (=> mbol = 8.539+-0.044 IAU2015 scale), Rad=0.322+-0.005Rsun, Teff=3366+-28K, BCv = mbol - V = 8.539 - 10.572 = -2.033. BC_Ks = mbol - Ks = 8.539 - 5.837 = 2.702. V-Ks = 10.572 - 5.837 = 4.735. G=9.4110 0.0012, Bp-Rp=2.5684, Bp-G=1.4250, G-Rp=1.1434 GJ 3459 = LHS 1935 = LP 783-1 = L 672-9 = HIP 37217 = NLTT 18223 = 2MASS J07384089-2113276 *M3V: Reid95,Reid04(M3.0),Gaidos14(M3),1983nssl.conf..365M sdM3: Houdebine16 sdM3.3: Houdebine19 M3.1: Mann15 M3.4+-0.7: Sebastian21 M2: Stephenson75 This star stands out as having the absolute G magnitude among SIMBAD stars within 20pc that was in the middle of the tightest concentration of M_G values, and it also has pretty good agreement on M3 subtype. The densest absolute magnitude range is peaked at M_G=10.5145 (with LP_783-1 = LHS 1935 appearing at the peak). There are 23 stars with M_G between 10.50-10.53 within 20 pc (out of 2602 objects)! Koen10 reports: V=11.712, B-V=1.582, U-B=1.222, V-Rc=1.096, V-Ic=2.483. Ks= 7.063+-0.023(2MASS) => V-Ks = 11.712 - 7.063 = 7.649. Teffs: 3236+-52K(Casagrande08), 3300K(Cifuentes21), 3358+-60K(Mann15), 3385+-63K(Muirhed18), 3402+-21K(Houdebine19) 3406+-61K(Gaidos14), 3426+-51K(Schweitzer19), 3446+-19K(Fouque18), 3661(3484-3915)K(GaiaDR2) => = 3402K. Radius: 0.3150+-0.0160Rsun(Mann15), 0.318+-0.013Rsun(Muirhead18), 0.32+-0.04Rsun(Sebastian21), 0.3262+-0.0101Rsun(Cifuentes20). Mass: 0.290+-0.029Msun(Mann15), 0.29+-0.01Msun(Sebastian21), 0.319-0.014Msun(Muirhead18), 0.3201+-0.1043Msun(Cifuentes20) => = 0.305Msun. Metallicities: [Fe/H]=-0.18+-0.08(Mann15). M_G=10.5145, M_Ks=6.967. ### OTHER STARS L 98-59 = TOI-175 = 2MASS J08180763-6818468 = NLTT 19357 = M2: Gaidos14 M2.5V: Henry18 *M3+-1V: Kostov19 M3.4+-0.6: Sebastien21 Low metallicity M3V - now a famous nearby exoplanet host star (Kostov19) with multiple transiting planets. B=13.289+-0.027(APASS/DR9), V=11.71(Henry18), V=11.685+-0.017(APASS/DR9), R=10.61(Henry18), I=9.25(Henry18), J=7.933+-0.027(2MASS), H=7.359+-0.049(2MASS), Ks=7.101+-0.018(2MASS) => V-Ks = 11.71 - 7.101 = 4.609 (basically right near median for M3Vs). plx=94.2664+-0.0155mas(GaiaEDR3), plx=101.81+-2.37mas(Henry18) => Mv = 11.58+-0.01, M_Ks = 6.98+-0.02. Teffs: 3245(3218-3257)K(Anders19), 3308+-105K(Sebastien21), 3367+-150K(Kostov19), 3400+-92K(Kunder17#1), 3412+-49K(Cloutier19), 3415+-135K(Demangeon21) , 3426+-61K(Gaidos14), 3429+-157K(Stassun19), 3469+-68K(Muirhead18), 3477K(Kunder17#2), 3786(3564-4031)K(GaiaDR2), Mass: 0.273+-0.030(Demangeon21), 0.29+-0.01Msun(Sebastien21), 0.30Msun(Kervella22), 0.3007+-0.0123Msun(EEM calc using Ks, plx(GaiaEDR3), [Fe/H](Demangeon21)), 0.311+-0.004Msun(Muirhead18), 0.3124+-0.0032Msun(Cloutier19), 0.313+-0.014Msun(Kostov19), 0.33+-0.06Msun(Gaidos14). fbol=2.99±0.18×10−9 erg s−1 cm−2(Kostov19) => mbol = 9.813+-0.065 mag (IAU2015 scale). Lum: L=0.0113+-0.0006Lsun(Kostov19), L=0.015+-0.005Lsun(Gaidos14), L=0.01128+-0.00042Lsun(Demangeon21) => logL=-1.9477+-0.0162. [Fe/H] = -0.5+-0.5(Kostov19), -0.46+-0.26(Demangeon21). Using VKs calibration for M dwarfs, I find that the star is about 0.39 mag below the solar metallicity sequence: [Fe/H]=-0.27(JohnsonApps09 calibration), -0.48(SchlaufmanLaughlin10 calibration). ### M3Vs among nearest 100 systems GJ_687_ M3V 2002AJ....123.2002H NA NA GJ_752_A_ M3V 1991ApJS...77..417K 1.499 1.146 GJ_661_A_ M3V 2002AJ....123.2002H 1.502 1.010 (unresolved bin.) GJ_661_B_ M3V 2002AJ....123.2002H 1.502 1.010 (unresolved bin.) GJ_570_C_ M3:V 2012ApJ...753..156K 1.519 1.213 GJ_725_A_ M3V 1991ApJS...77..417K 1.537 1.104 GJ_388_ M3V 1994AJ....108.1437H 1.544 1.075 GJ_251_ M3V 1991ApJS...77..417K 1.585 1.218 GJ_628_ M3V 2002AJ....123.2002H 1.595 1.183 GJ_644_B_ M3:V 2012ApJ...753..156K 1.596 1.078 (unresolved bin.) GJ_860_A_ M3V 2002AJ....123.2002H 1.648 1.272 (unresolved bin.) => (B-V)(M3V) = 1.54, (U-B)(M3V)=1.17