B2V Garrison94 does not list a B2V anchor standard, but MK73 lists 22 Sco (HD 144218 as the B2V dagger standard. For some reason, rho Oph - the only B2V standard in MK43, was dropped in favor of several new standards for JM53. MK43 standard: rho Oph - B2V JM53 standard: bet^2 Sco ("bet Sco(ft)") - B2V 22 Sco - B2V zet Cas - B2V xi Cas - B2V o Cas - B2V HD 191746 - B2V HD 208947 - B2V HD 218440 - B2V Garrison67 standard: Cl* NGC 2244 JOHN 14 - B2IV-V [Morgan65, but "V"=>"IV-V"] Cl* NGC 2244 JOHN 16 - B2V [Morgan65] Cl* NGC 2244 JOHN 15 - B2V [Morgan65] Lesh68 standards: 22 Sco - B2V (prim. stan.) 51 Cyg - B2V (prim. stan.) HD 36430 - B2V (sec. stan.) HD 43955 - B2V (sec. stan.) Hiltner69 standard: 22 Sco - B2V Walborn71 standard: HD 42401 - B2V Cowley72 standard: sig Sgr - B2V MK73 dagger standard: 22 Sco - B2V Houk75 standard: 22 Sco - B2V (primary standard) Garrison77 standard: 22 Sco - B2V MK78 standards: bet^2 Sco ("bet Sco(ft)") - B2V HR 1890 - B2Vh HR 1851 - B2Vh mu Cen - B2V:e Garrison79 standards: 22 Sco - B2V 13 Sco - B2V bet Sco B - B2IV-V Keenan85 standard: bet Sco B - B2V Walborn90 standard: HD 42401 - B2V WiegertGarrison98 stan: bet Sco C - B2V 22 Sco - B2V GrayAtlas standard: 22 Sco - B2V GrayNStars standards: 22 Sco - B2V Garcia89 lists 8 B2V standards: HD 3901, 4180, 144218, 147934, 148605, 191746, 208947, 218440 Skiff08 lists 6 stars as B2V standards (and variants): HD 148605 (B2V; MK73), HD 175191 (B2V; MK73), HD 120324 (B2V:e; MK78), HD 144218 (B2V; MK78), HD 36485 (B2Vh; MK78), HD 37017 (B2Vh; MK78). All Q-method calculations in this file have been reevaluated using the newest calibration (10/9/2011). B-V(B2V) = -0.197 ; EEM dereddened sec. stan. HD 42401 (via Q-method) B-V(B2V) = -0.210 ; EEM dereddened N=56 HIP B2V (E(B-V)<0.1, Q-method) B-V(B2V) = -0.213 ; EEM dereddened sec. stan. 13 Sco (via Q-method) B-V(B2V) = -0.215 ; U-B=-0.79, trend Q-method B-V(B2V) = -0.216 ; EEM dereddened weak stan. 22 Sco (via Q-method) B-V(B2V) = -0.22 ; KenyonHartmann95 B-V(B2V) = -0.229 ; EEM dereddened prim. stan. bet^2 Sco (via Q-method) B-V(B2V) = -0.23 ; Garrison67 B-V(B2V) = -0.231 ; EEM dereddened weak stan. HD 191746 (via Q-method) B-V(B2V) = -0.24 ; JohnsonMorgan53,Morgan53,Johnson63,JohnsonBorgman63,Johnson66 B-V(B2V) = -0.24 ; Fitzgerald70, Morgan71, SchmidtKaler82 => adopt (B-V)(B2V) = -0.215 [updated 2/7/2020] U-B(B2V) = -0.731 ; EEM dereddened sec. stan. HD 42401 (via Q-method) U-B(B2V) = -0.775 ; EEM dereddened N=56 HIP B2V stars (E(B-V)<0.1, Q-method) U-B(B2V) = -0.784 ; EEM dereddened sec. stan. 13 Sco (via Q-method) U-B(B2V) = -0.793 ; EEM dereddened weak stan. 22 Sco (via Q-method) U-B(B2V) = -0.81 ; Fitzgerald70 U-B(B2V) = -0.838 ; EEM dereddened prim. stan. bet^2 Sco (via Q-method) U-B(B2V) = -0.84 ; Schmidt-Kaler82 U-B(B2V) = -0.844 ; EEM dereddened weak stan. HD 191746 (via Q-method) U-B(B2V) = -0.85 ; Bessell98 U-B(B2V) = -0.86 ; Johnson63, Johnson66 => adopt (U-B)(B2V) = -0.79 *** [updated 2/7/2020] => adopt Q(B2V) = -0.636 [updated 2/7/2020] => adopt (V-I)(B2V) = -0.229 => adopt (V-R)(B2V) = -0.094 => adopt (R-I)(B2V) = -0.135 (V-Ks)(B2V)= -0.437 ; HIP_35083_ B2V d= 208.812pc, (B-V)=0.007 (dereddened from Kervella19) (V-Ks)(B2V)= -0.513 ; HIP_38455_ B2V d= 240.906pc, (B-V)=0.012 (dereddened from Kervella19) (V-Ks)(B2V)= -0.562 ; HIP_38593_ B2V d= 242.66pc, (B-V)=0.011 (dereddened from Kervella19) (V-Ks)(B2V)= -0.564 ; HIP_91918_ B2V d= 145.285pc, (B-V)=0.020 (dereddened from Kervella19) (V-Ks)(B2V)= -0.567 ; HIP_70300_ B2V d= 119.589pc, (B-V)=0.012 (dereddened from Kervella19) (V-Ks)(B2V)= -0.601 ; HIP_28756_ B2V d= 286.862pc, (B-V)=0.008 (dereddened from Kervella19) (V-Ks)(B2V)= -0.602 ; from intrinsic color trend for (U-B)=-0.79 (V-Ks)(B2V)= -0.634 ; HIP_60823_ B2V d= 125.723pc, (B-V)=0.014 (dereddened from Kervella19) (V-Ks)(B2V)= -0.637 ; HIP_68862_ B2V d= 153.351pc, (B-V)=0.013 (dereddened from Kervella19) (V-Ks)(B2V)= -0.751 ; HIP_38500_ B2V d= 244.26pc, (B-V)=0.029 (dereddened from Kervella19) => adopt (V-Ks)(B2V) = -0.602 [updated 4/8/2022] => adopt (V-J)(B2V) = -0.458 [updated 4/8/2022] => adopt (V-H)(B2V) = -0.570 [updated 4/8/2022] => adopt (H-Ks)(B2V) = -0.032 [updated 4/8/2022] => adopt (J-H)(B2V) = -0.113 [updated 4/8/2022] (Ks-W1)(B2V) = 0.023 ; EEM trend for d<30pc for B-V=-0.210 => adopt (Ks-W1)(B2V) = 0.023 [updated 12/29/2019] (Bp-Rp)(B2V) = -0.318 ; Evans18 trend for V-I=-0.229 (g-r)(B2V) = -0.475 ; Covey07 (G-V)(B2V) = -0.008 ; fit for B dwarfs from Kervella19 corrected for E(B-V), eval for (V-Ks)=-0.602 => adopt (G-V)(B2V) = -0.008 [updated 4/8/2022] Teff(B2V) = 22400 K ; Theodossiou90 Teff(B2V) = 22000 K ; Crowther97/Fig.3 Teff(B2V) = 22000 K ; Schmidt-Kaler82 Teff(B2V) = 22000 K ; Bertone04[ATLAS] Teff(B2V) = 21700 K ; non-standard HD 36285 (Nieva14) Teff(B2V) = 21618 K ; B-V=-0.216 => Teff(Bessell98,logg=4.3) Teff(B2V) = 21500 K ; Bohm-Vitense81 Teff(B2V) = 21400 K ; Chavez95 (+400-200K) Teff(B2V) = 21380 K ; Bessell98 Teff(B2V) = 20800 K ; non-standard HD 122980 (Nieva14) Teff(B2V) = 20700 K ; non-standard HD 35708 (Nieva14) Teff(B2V) = 20693 K ; sec. stan. 13 Sco ; EEM median 3 Teffs Teff(B2V) = 20600 K ; median for Braganca12 B2V stars (N=48) Teff(B2V) = 20592 K ; prim. stan. beta2 Sco (median Teff) Teff(B2V) = 20500 K ; deprecated stan. HD 42401 (Teff from Williams09) Teff(B2V) = 20324 K ; Q=-0.639 => Nieva13 calibration Teff(B2V) = 20010 K ; B-V=-0.216 => Teff(Napiwotzki93) Teff(B2V) = 19679 K ; EEM N=180 Teffs Teff(B2V) = 19500 K ; GrayCorbally09 Teff(B2V) = 19500 K ; GrayCorbally94 Teff(B2V) = 19490 K ; U-B=-0.79 => Bessell98(Teff) Teff(B2V) = 19055 K ; Simon-Diaz17 for B2V (N=15) Teff(B2V) = 18858 K ; Flower96 Teff for B-V = -0.22 => adopt Teff(B2V) = 20600 K (logT = 4.314) [updated 9/16/2019] Mv(B2V) = -2.7 mag ; Wegner07 Mv(B2V) = -2.5 mag ; GrayCorbally09 Mv(B2V) = -2.47 mag ; Russeil03 Mv(B2V) = -2.4 mag ; Schmidt-Kaler82 Mv(B2V) = -2.28 mag ; Bowen08 Mv(B2V) = -1.8 mag ; HD 147934 (Jaschek98) Mv(B2V) = -1.78 mag ; Upper Sco main sequence (B-V=-0.216; rms=+-0.39 mag) Mv(B2V) = -1.72 mag ; ONC main sequence (B-V=-0.216; rms=+-0.48 mag) Mv(B2V) = -1.66 mag ; median Mv for B2V calc using Kervella19 HIP & Gaia DR2 Mv(B2V) = -1.43 mag ; sec. stan. 13 Sco (see below) Mv(B2V) = -1.2 mag ; pri. stan. bet^2 Sco (see below) Mv(B2V) = -0.6 mag ; HD 148605 (Jaschek98; but deprecated B2V => now B2.5V by Walborn) => adopt Mv(B2V) = -1.80 mag [updated 9/20/2019] => adopt M_Ks(B2V) = -1.198 mag = Mv - (V-Ks) = -1.80 - -0.602 [updated 12/30/2020] BCv(B2V) = -2.22 mag ; Schmidt-Kaler82(BCv=-2.35 + 0.13 offset) BCv(B2V) = -2.095 mag ; Code76(Teff=20600K, set so BCv(5772K)=-0.085) BCv(B2V) = -2.052 mag ; Flower96(Teff=20600K, set so BCv(5772K)=-0.085 BCv(B2V) = -2.036 mag ; Nieva13(Teff=20600K) BCv(B2V) = -2.033 mag ; LanzHubeny07(Teff=20600K,logg=4.0,Z/Zsun=1) BCv(B2V) = -2.031 mag ; Bessell98(ATLAS9,logg=4.0,Teff=20600K, set so BCv(5772K)=-0.085 BCv(B2V) = -2.014 mag ; Balona94(Teff=20600K, set so BCv(5772K)=-0.085 BCv(B2V) = -1.956 mag ; Bertone04[ATLAS,Teff=20600K) => adopt BCv(B2V) = -2.03 [updated 9/16/2019] logL(B2V) = 3.428 ; Mv=-1.8, BCv=-2.03 => Mbol = -3.830 logL(B2V) = 3.40 ; sec. stan. 13 Sco logL from Hohle10 logL(B2V) = 3.374 ; logL/Teff trend for OB dwarf EBs (Torres10; Teff=20600) => adopt logL(B2V) = 3.428 dex [updated 9/26/2019] => adopt Mbol(B2V) = -3.830 mag [updated 9/26/2019] Mass(B2V) ~ 6.5 Msun ; pri. stan. bet2 Sco Mass(B2V) = 6.70 Msun ; EEM Mv vs. Mass fit for binaries (Mv=-1.8) Mass(B2V) = 6.84 Msun ; Ekers15 ML calibration for logL=3.38 Mass(B2V) = 7.17 Msun ; EEM Teff vs. Mass fit for binaries (Teff=20600K) Mass(B2V) = 7.23 Msun ; EEM logL vs. Mass fit for binaries (logL=4.38) Mass(B2V) = 7.28 Msun ; MIST/Choi16 solar tracks logT=4.314, logL=3.428 Mass(B2V) = 7.29 Msun ; Bertelli09 tracks (Z=0.017,Y=0.27) for Teff=20300K,logL=3.38 Mass(B2V) = 7.42 Msun ; mass for deprecated B2V standard HD 42401 (eclipsing binary) Mass(B2V) = 8.46+-0.12 Msun ; Eclipsing binary QX Car B (Torres10) Mass(B2V) = 8.50+-0.62 Msun ; Hohle10 Mass(B2V) = 8.62 Msun ; Harmanec88 Mass(B2V) = 9.25+-0.12 Msun ; Eclipsing binary QX Car A (Torres10) Mass(B2V) = 10.262+-0.084 Msun ; Eclipsing binary V578 Mon B (Torres10) => adopt Mass(B2V) = 7.3 Msun (wide dispersion) [updated 4/16/2022] Rad(B2V) = 5.60 Rsun ; radius for deprecated B2V standard HD 42401 (eclipsing binary) Rad(B2V) = 4.143 Rsun ; pri. stan. bet2 Sco Kervella04 Rad(B2V) = 4.064 Rsun ; Teff=20600K, logL=3.428 => adopt Rad(B2V) = 4.064 Rsun [updated 9/26/2019] # Primary Standards HD 144218 = bet^2 Sco = 8 Sco B = bet Sco B = HR 5985 *B2V: JM53,Bertiau58,Slettebak63,Levato75,MK78,Abt81,Gahm83,Keenan85,Garcia89,Houk B2IV-V: Lesh68,Garrison79(stan) B2IV/V: Garrison67 B3V: Morris61 Companion to B0.5V star bet^1 Sco (A). Jaschek64: majority say B2V, with one B3V. Mermilliod91 photometry: V=4.903+-0.014, B-V=-0.024+-0.008, U-B=-0.690+-0.014 => updated Q-method (10/8/2011) => (B-V)o=-0.229, (U-B)o=-0.838, E(B-V)= 0.205, Av=0.666. VanLeeuwen07 plx = 8.19+-1.17 mas => D = 122+-18 pc. Mv = -1.20 +- 0.31 mag. Teffs: 19657K(EEM,Hauck97 phot.=>Napiwotzki93 calibration), 20150K(Glagolevskij19), 20160K(Philip80), 20417K(deGeus89), 20766K(U-Bo=>Bessell98), 20866K(EEM,Hauck97 beta phot.=>BalonaShobbrook84 calibration), 21042K(EEM,Hauck97 phot.=>Balona94 calibration) => median Teff = 20592K. Rad=3.00Rsun(Glagolevskij19), 4.143+-0.207 Rsun (Kervella04). M=4.498+-0.225Msun(Kervella19), 6.54Msun(Tokovinin20), 7.59Msun(Glagolevskij19) ~> ~ 6.5 Msun. # Secondary Standard 13 Sco = HD 145482 = HR 6028 = HIP 79404 *B2V: Jaschek78(Garrison67),Slettebak68,Hiltner69,Garrison79(stan),Houk82(Garrison) B2.5Vn: Bertiau58 B3Vn: deVaucoleur57 B3: Cannon Jaschek64 shows 5 different types published for 13 Sco (B2/3V/Vn), but consistent use by Hiltner & Garrison. Mermilliod91: V=4.580+-0.007, B-V=-0.159+-0.006, U-B=-0.746+-0.012 => updated Q-method calibration (10/9/2011) => (B-V)o = -0.213, E(B-V) = 0.054, (U-B)o = -0.784, Av=0.175. VanLeeuwen07 plx = 6.81+-0.16 mas => D = 147+-3 pc. Mv = -1.43+-0.05 mag. Hauck97 photometry dereddened using Castelli91: (b-y)o=-0.111, c0=0.181, E(b-y)=0.042, Av=0.184. Teffs: 19223K(EEM,Hauck97 phot.=>Napitwotski93 calibration), 19339K(U-Bo=>Bessell98), 19385K(Philip80), 19941K(EEM,Hauck97 phot.=>Balona94 calibration), 20004K(EEM,Hauck97 phot.=>BalonaShobbrook84 beta calibration), 22000K(Snow94) => median Teff = 20693 K. # Variant Standard mu Cen = HD 120324 = HR 5193 B2V:e: MK78 *B2Vnep: Levenhagen06,Bertiau58(B2V:nep) B2IV-Ve: Houk78(Hiltner69),Slettebak82 B2p: Cannon B2: Mendoza58 B3Ve: deVaucouleurs57 MK78 shows this as a prototypical Be star classified as "B2V:e". Jaschek64 lists 5 different classifications, but all B2-B3Ve UCL Member. Could be considered a "B2Ve" standard? # Deprecated Standards HD 42401 = V1388 Ori = BD+12_1049 *B2V: Kennedy83(Walborn71),Walborn90 B2.5IV-V+B3V: Williams09(based on Teff and logg) B5: Cannon Few classifications, but considered a standard by Walborn90. Unfortunately the star is an eclipsing binary with period 2.187 days (Williams09), and a dip of ~0.35 mag in Hp band (Malkov06). Williams09 demonstrates the variability (radial velocity shifts) of the He I lines M91: V=7.442+-0.073, B-V=-0.042+-0.015, U-B=-0.620+-? => updated Q-method calibration (10/9/2011) => (B-V)o=-0.197, (U-B)o=-0.731, E(B-V)= 0.155, Av=0.505. Insufficient Hauck97 ubvy photometry. VanLeeuwen07 plx = 1.06+-0.58 mas (i.e. low S/N). Williams09 derives a distance of 832+-89 pc and age of >~25 Myr, and individual Teffs of 20500+-500K(A) and 18500+-500K(B). 22 Sco = HD 148605 = HR 6141 = i Sco B2V: Jaschek64(all),Thacheray67(B2Vn),Lesh68(stan),Slettebak68,Hiltner69(stan),MK73,Houk,Garrison77(stan),Jaschek78(Garrison67),Garrison79(stan),Kennedy83(all),GrayAtlas *B2.5V: Walborn90 B3V: Houk88 B3: Cannon Long, rich history as B2V standard, but Walborn90 calls it B2.5V. I've decided to deprecate this star as a standard due to this recent classification by Walborn. Mermilliod91: V=4.782+-0.007, B-V=-0.125+-0.020, U-B=-0.728+-0.026 => updated Q-method calibration (10/9/2011) => (B-V)o=-0.216, (U-B)o=-0.793, E(B-V)= 0.091, Av=0.294. HD 191746 = HIP 99400 B2V: JM53,Garcia89 B2IV: Jaschek78(Guetter68),Kennedy83(Guetter68) B2III/IV: Claussen79 B3: Cannon Good agreement on B2 temperature type, but only JM53 calls it dwarf. No use as standard after JM53? Mediocre standard. M91: V=7.170+-?, B-V=0.010+-?, U-B=-0.670+-? => revised Q-method calibration (10/9/2011) => (B-V)o=-0.231, (U-B)o=-0.844, E(B-V)= 0.241, Av=0.782. HD 218440 = HR 8803 B2V: JM53,Guetter68,Garcia89 B2.5IV: Jaschek78(Lesh68) B3III/V: Maury1897(in Skiff12) Spectroscopic binary. Lesh adopted later type and subgiant instead of dwarf luminosity class. Doesn't seem to have been used much as a standard after JM53. M91: V=6.391+-0.010, B-V=-0.011+-0.010, U-B=-0.636+-0.005 => updated Q-method (10/9/2011) => (B-V)o=-0.212, (U-B)o=-0.780, E(B-V)= 0.201, Av=0.652. HD 3901 = ksi Cas = 19 Cas = HR 179 B2V: JM53,Garcia89,Hoffleit91 B2.5V: Jaschek78(Lesh68),Kennedy83 B3: Cannon Jaschek64: vast majority list B2V (one B3IV). Basically the only two good classifications are JM53 and Lesh68. HD 208947 = HR 8384 *B2V: JM53,Lesh68,Garcia89 B3V: Abt84,Ahmad52 B3: Cannon,Petrie67(B3+B3) I'll adopt the Morgan & Lesh B2V type, but probably a mediocre standard, given the disagreement among other expert classifiers. M91: V=6.430+-0.030, B-V=-0.055+-0.005, U-B=-0.685+-0.005 => updated Q-method calibration (10/9/2011) => (B-V)o=-0.218, (U-B)o=-0.802, E(B-V)= 0.163, Av=0.530. HD 147933 = rho Oph B2V: MK43,Bertiau58,Hiltner69,Abt83,Abt86,Garcia89 B2IV/V: Murphy69 *B2IV+B2V: Garrison67,Racine68 B2/3V: Houk88 B3IV: Morris61 B1.5V: Buscombe69 B5: Cannon Jaschek64 lists B2V, B3IV, and B5N: ~3" binary. Probably not the best standard as it is tight binary. M91(combined): V=4.600+-0.016, B-V=0.230+-0.007, U-B=-0.568+-0.011 => updated Q-method calibration (10/9/2011) => (B-V)o=-0.254, (U-B)o=-0.917, E(B-V)= 0.484, Av=1.572. HD 3360 = zet Cas = 17 Cas = HR 153 B2V: Ahmad52,JM53 *B2IV: MK43,Underhill57,MK73,Lesh68,Jaschek78(Lesh68),Garcia89,Hoffleit91 B3: Cannon Jaschek64 shows mostly B2V with a few B2IV and B2.5IV. Johnson66: V=3.66, B-V=-0.19, U-B=-0.89 => updated Q-method calibration (10/9/2011) => (B-V)o =-0.262, (U-B)o = -0.943, E(B-V) = 0.072, Av=0.232. The consensus and MK73 suggest B2IV - little doubt about temperature type (B2). ome Cas = HD 4180 = 46 Cas = HR 548 B2V: JM53 B2.5Ve: Steele99 B2.5V: Schmidt-Kaler82 B3: Mendoza58 B3IV: Miczaika53 B3V: Cucchiaro82 B3III/V: Maury1897 B4ne: Merrill33 B5III: Williams36, Chalonge52, Lesh68 B5IVe: Slettebak82 "\omicron Cas" is definitely listed in JM53 (p. 321). Some of the early types are from the Skiff compendium, and not necessarily reported as written. Obviously a huge dispersion in subtypes from B2 to B5 (could this be reflecting real variability?). Not a good standard. HD 35468 = gam Ori B2V: MK43 *B2III: Morgan55,Lesh68,MK73,Jaschek78(M55),Garcia89,Walborn90 B2: Cannon Jaschek64: split of B2III and B2IV. So this star turned from B2V => B2III and stuck. Not a dwarf. HD 175191 = sig Sgr = HR 7121 = HIP 92855 *B2.5V: MK73,Garrison79(stan),Houk82 B2V: Cowley72(stan) B3IV: Hiltner69 B3: Cannon B4IV: Buscombe60,Morris61,Buscombe69 Jaschek64 shows B3IV-V,B3V,B4IV,B4V, however most classifications predate MK73 (and post-MK73 consider it B2.5V). Having 3 "B4IV" classifications scares me a bit regarding considering this an authoritative B2.5V standard. Parallax = 14.32+-0.29 mas (van Leeuwen07), hence it can be considered most likely unreddened. Q-method (10/9/2011): M91: V=2.078+-0.034, (B-V)=-0.213+-0.017, (U-B)=-0.749+-0.011 => (B-V)o = -0.221, (U-B)o = -0.812, E(B-V)=0.000. Hauck97 photometry dereddened following Castelli91 => (b-y)o=-0.110, c0=0.217, E(b-y)=0.019, Av=0.082. Teffs: 18606K(EEM, Hauck97 phot.=>Napiwotzki93 calibration), 18890+-1150K(Zorec09), 19171K(EEM, Hauck97 phot.=>BalonaShobbrook84 beta calibration), 19125K(EEM, Hauck97 phot.=>Balona94 calibration), 20400K(Snow94) => median Teff = 19171K. HD 36485 = HR 1851 = del Ori C (companion ("ft")) (V=6.9) *B2V: Morgan55,Murphy69,MK78(B2Vh),Houk99(Warren) B2IV-V: Lesh68 B2.5V: Levato75 B3V: Berger58 B4IV: Abt83 B6: Wilson50 "h" is helium? V=6.9 star 52" North comp to V=2.5 O9 star HD 36486. Some dispersion in the published types. MK78 lsts "B2Vh" standard of "del Ori(ft) = HR 1851". HD 37017 = HR 1890 B2V: Morgan52,MK78(B2Vh;stan),Levato75, B2IV: Schild71 B1.5V: Sharpless52,Jaschek78(Lesh68),Abt77(B1.5Vp) B0: Cannon B2/3V: Houk99(q=3) He strong according to Abt77 & 1996VA......8...83M. Types vary a bit in the literature, probably lousy standard. HD 197511 = 51 Cyg B2V: Slettebak55,Lesh68(standard; in Jaschek64) B3: Cannon B3III: Cucchiaro80 Only Lesh68 considered this a standard, but that's probably not enough to put this on par with the other standards that have been much more heavily used over the decades. Few classifications. 3.1" binary in WDS (V1=5.38, V2=12.40). HD 36430 = Parenago 679 = ALS 16198 B2V: Sharpless52,Lesh68(sec. standard) B2.5Vsn: Abt77 B3V: Houk99(q=1) B3: Cannon Only Lesh68 considered this a standard, but Abt & Houk say >B2V. HD 43955 = HR 2266 B2V: Slettebak55,Lesh68(sec. standard, in Jaschek78) B2/3V: Houk88 B3: Cannon Only Lesh68 considered this a standard. Few classifications. HD 37129 = Parenago 2314 = SAO 132345 B2V: Jaschek64(only; "B2Vp"),Abt68,Jaschek78(Sharpless52;"B2Vp") B2.5Vsn: AbtLevato77 B3III/IV: Houk99 B5: Cannon Abt68's B2V standard, but called "B2.5Vsn" in Abt77. vsini=65 km/s (Houk). Insufficient agreement and use to be considered a standard. Cl* NGC 2244 JOHN 14 B2IV-V: Garrison67(stan) B2V: Morgan65, Perez87 B3V: Johnson62 B3: Hayford63 B1.5V: Massey95 B0V: Voroshilov85 Garrison67 adopts from Morgan65, but switches "V"=>"IV-V". Cl* NGC 2244 JOHN 16 B2V: Morgan65,Garrison67(stan) Cl* NGC 2244 JOHN 15 B2V: Morgan65,Garrison67(stan) # Other Stars HD 35912 = HR 1820 = HIP 25582 (J0528+0117; V=6.4) B2V: Sharpless52(B2),Lesh68,Cuchiaro76,Abt77 Kap Cen B2V: Garrison96 One of 4 B2V (or variant) stars in Garrison96's table "The Brightest Stars". Not considered a standard anywhere. Alf Ara B2Vne: Garrison96 One of 4 B2V (or variant) stars in Garrison96's table "The Brightest Stars". Not considered a standard anywhere. Sig Cen = HD 108483 = HIP 60823 = HR 4743 *B2V: Bertiau58,Hiltner69,Cucchiaro80(UV) B3Vn: deVaucoleurs57 V=3.91(Johnson66), V=3.909+-0.007 (Mermilliod91), B-V=-0.19(Johnson66), B-V=-0.195+-0.006 (Mermilliod91), U-B=-0.77(Johnson66), U-B=-0.775+-0.015 (Mermilliod91). logN_HI = 19.32 cm^-2 (Crawford91; Na I). This translates to E(B-V)=0.004 from Savage & Mathis 1979. So (B-V)o = -0.199, (U-B)o = -0.778, Q = -0.635. HD 36166 = HR 1833 (J0529+0147) *B2V: Lesh68, Abt77, 1976A&AS...26..241C B1.5V: Sharpless52 V=5.779+-0.003(Mermilliod91), V=5.780+-0.007(Cousins71), B-V=-0.202+-0.004(Mermilliod91), B-V=-0.195+-0.005(Cousins71), B-V=-0.20(Johnson66), U-B=-0.843+-0.006(Mermilliod91), U-B=-0.85(Cousins71), U-B=-0.84(Johnson66). Cousins71 standard. logN_HI = 20.32+-0.22 (Bohlin83). Using Savage & Mathis 1979 relation, this suggests E(B-V) = 0.044 mag. Hence Q=0.698, (B-V)o = -0.246, (U-B)o=-0.874. Garrison96 lists 4 B2V (or variant) stars in their table "The Brightest Stars": bet Mus A, kap Cen, pi Sco A, alf Ara. ### IR MAGNITUDES FOR NEARBY B2Vs ID 2MASS_J Jmag eJmag Hmag eHmag Ksmag eKsmag Vmag B-V U-B E(B-V) Av plx eplx W1 eW1 Vo Jo Ko HD 142184 15535586-2358410 5.437 0.030 5.418 0.044 5.365 0.023 AAA 5.412 -0.033 -0.615 0.165 0.536 7.0774 0.1450 5.289 0.060 HD 172910 18441936-3538311 5.231 0.021 5.387 0.026 5.343 0.023 AAA 4.857 -0.183 -0.729 0.017 0.055 6.9525 0.2898 5.172 0.042 V* V1003 Sco 16382629-4323543 5.864 0.024 5.909 0.034 5.933 0.023 AAA 5.825 -0.022 -0.609 0.176 0.574 5.883 0.045 1978rmsa.book.....M HD 36485 +B2Vh 1978rmsa.book.....M HD 37017 +B2Vh 1978rmsa.book.....M HD 120324 +B2V:e 1978rmsa.book.....M HD 144218 +B2V 1973ARA&A..11...29M HD 148605 +B2V 1973ARA&A..11...29M HD 175191 +B2V