B4V Garrison94 does not list a B4V anchor standard, nor does MK73 list a B4V dagger standard. Unfortunately "B4V" is in this no-man's land between the very hot dwarfs (O-B3 stars) covered by e.g. Walborn and others, and the late Bs (B7-A0 stars) covered in more detail by Gray and collaborators. The only B4V standard I've seen in the literature: Lesh68 standard: 90 Leo - B4V # No Standard MK43, JM53, Garrison67, Hiltner69, Cowley72, MK73, Houk75, Garrison77, MK78, Garrison79, Keenan85, Garcia89, GrayAtlas, GrayNstars do not list a B4V standard. Johnson66 omits listing colors for B4V stars. Skiff08 did not flag any stars as B4V standards. All Q-method dereddening calculations in this file have been updated with the revised calibration (10/9/2011). B-V(B4V) = -0.18 ; Morgan53, Johnson63 (interp. by EEM B3V-B5V) B-V(B4V) = -0.18 ; Fitzgerald70, Morgan71(halfway_B3_B5) B-V(B4V) = -0.175 ; dereddened weak standard 90 Leo B-V(B4V) = -0.17 ; halfway between B3V (-0.18) and B5V (-0.16) B-V(B4V) = -0.166 ; EEM dereddened 35 HIP B4V stars (Q-method, E(B-V)<0.1) B-V(B4V) = -0.16 ; KenyonHartmann95 B-V(B4V) = -0.150 ; EEM dereddened nearest B4V star HD 103079 The bluest B4V star that I can find is HIP 30788 (B-V = -0.169+-0.007), so <(B-V)o> is probably near this value. U-B(B4V) = -0.558 ; EEM dereddened nearest B4V star HD 103079 U-B(B4V) = -0.619 ; EEM dereddened 35 HIP B4V stars (Q-method, E(B-V)<0.1) U-B(B4V) = -0.63 ; Fitzgerald70 U-B(B4V) = -0.645 ; Schmidt-Kaler82 halfway (B3V-B5V) U-B(B4V) = -0.651 ; EEM dereddened weak standard 90 Leo U-B(B4V) = -0.66 ; Bessell98 => adopt (U-B)(B4V) = -0.619 *** => adopt (B-V)(B4V) = -0.165 => adopt Q(B4V) = -0.500 (=(U-B)-0.72*(B-V) = -0.619 - 0.72*-0.165) => adopt (V-I)(B4V) = -0.175 => adopt (V-R)(B4V) = -0.074 => adopt (R-I)(B4V) = -0.101 (V-Ks)(B4V) = -0.354 ; HIP_60000_ B4V d= 93.2575pc, (B-V)=0.007 (dereddened from Kervella19) (V-Ks)(B4V) = -0.398 ; HIP_63945_ B4V d= 122.175pc, (B-V)=0.013 (dereddened from Kervella19) (V-Ks)(B4V) = -0.403 ; HIP_35202_ B4V d= 278.629pc, (B-V)=0.016 (dereddened from Kervella19) (V-Ks)(B4V) = -0.428 ; HIP_39238_ B4V d= 234.907pc, (B-V)=0.019 (dereddened from Kervella19) (V-Ks)(B4V) = -0.445 ; HIP_30700_ B4V d= 327.654pc, (B-V)=0.028 (dereddened from Kervella19) (V-Ks)(B4V) = -0.447 ; from intrinsic color sequence for (U-B)o=-0.619 (V-Ks)(B4V) = -0.462 ; HIP_30788_ B4V d= 134.716pc, (B-V)=0.002 (dereddened from Kervella19) (V-Ks)(B4V) = -0.467 ; HIP_52736_ B4V d= 150.173pc, (B-V)=0.020 (dereddened from Kervella19) (V-Ks)(B4V) = -0.479 ; HIP_39138_ B4V d= 142.857pc, (B-V)=0.005 (dereddened from Kervella19) (V-Ks)(B4V) = -0.527 ; HIP_58326_ B4V d= 166.806pc, (B-V)=0.029 (dereddened from Kervella19) => adopt (V-Ks)(B4V) = -0.447 [updated 4/8/2022] => adopt (V-J)(B4V) = -0.338 [updated 4/8/2022] => adopt (V-H)(B4V) = -0.431 [updated 4/8/2022] => adopt (H-Ks)(B4V) = -0.016 [updated 4/8/2022] => adopt (J-H)(B4V) = -0.092 [updated 4/8/2022] (Ks-W1)(B4V) = 0.028 ; EEM trend for d<30pc for B-V=-0.165 => adopt (Ks-W1)(B4V) = 0.028 [updated 12/29/2019] (Bp-Rp)(B4V) = -0.245 ; Evans18 trend for V-I=-0.175 (g-r)(B4V) = -0.437 ; Covey07 interp B3V -0.46 to B5/7V -0.39 (G-V)(B4V) = 0.004 ; fit for B dwarfs from Kervella19 corrected for E(B-V), eval for (V-Ks)=-0.447 => adopt (G-V)(B4V) = 0.004 [updated 4/8/2022] Teff(B4V) = 17111 K ; deprecated standards 90 Leo (median Teff) Teff(B4V) = 17100 K ; Theodossiou90 Teff(B4V) = 17050 K ; Schmidt-Kaler82 halfway B3V-B5V Teff(B4V) = 17000 K ; Bohm-Vitense81 Teff(B4V) = 16866 K ; Bessell98 Teff(B4V) = 16813 K ; B-V=-0.166 => Teff(Bessell98,logg=4.3) Teff(B4V) = 16780 K ; median for Braganca12 B4V stars (N=41) Teff(B4V) = 16737 K ; EEM N=66 Teffs Teff(B4V) = 16700 K ; Chavez95 (+-100K) Teff(B4V) = 16490 K ; Bertone04[ATLAS] Teff(B4V) = 16400 K ; interp B-V vs. Teff B3V-B4V for B-V=-0.165 Teff(B4V) = 16000 K ; Crowther97/Fig.3 Teff(B4V) = 15750 K ; interp. (B3V-B5V) GrayCorbally09 Teff(B4V) = 15727 K ; U-B=-0.619 => Teff(Bessell98) Teff(B4V) = 15488 K ; Simon-Diaz17 for B4V (N=1; HD 21278) Teff(B4V) = 15421 K ; B-V=-0.166 => Teff(Napiwotzki93) Teff(B4V) = 14787 K ; Flower96 Teff for B-V = -0.17 Teff(B4V) = 14654 K ; non-standard HD 103079 (photometric Teff) => adopt Teff(B4V) = 16400 K (logT = 4.215) [updated 4/4/2020] Mv(B4V) = -0.54 mag ; Upper Sco main sequence (B-V=-0.166, rms=+-0.39 mag) Mv(B4V) = -0.76 mag ; ONC main sequence (B-V=-0.166, rms=+-0.48 mag) Mv(B4V) = -1.0 mag ; interp B3V (Mv=-1.1) & B5V (Mv=-0.7) Mv(B4V) - -1.12 mag ; median Mv for B4V calc using Kervella19 HIP & Gaia DR2 Mv(B4V) = -1.28 mag ; Wegner07 Mv(B4V) = -1.4 mag ; GrayCorbally09 Mv(B4V) = -1.4 mag ; Schmidt-Kaler82(halfway B3V-B5V) => adopt Mv(B4V) = -1.00 mag [adopted 4/4/2020] => adopt M_Ks(B4V) = -0.553 mag = Mv - (V-Ks) = -1.0 - -0.447 [updated 12/30/2020] BCv(B4V) = -1.589 mag ; Code76(Teff=16400K, set so BCv(5772K)=-0.085) BCv(B4V) = -1.57 mag ; Schmidt-Kaler82(BCv=-1.70+0.13 offset) BCv(B4V) = -1.539 mag ; Flower96(Teff=16400K, set so BCv(5772K)=-0.085 BCv(B4V) = -1.549 mag ; Nieva13(Teff=16700K) BCv(B4V) = -1.494 mag ; Bessell98(ATLAS9,logg=4.0,Teff=16400K, set so BCv(5772K)=-0.085 BCv(B4V) = -1.455 mag ; LanzHubeny07(Teff=16400K,logg=4.0,Z/Zsun=1) BCv(B4V) = -1.427 mag ; Balona94(Teff=16400K, set so BCv(5772K)=-0.085 BCv(B4V) = -1.383 mag ; Bertone04[ATLAS,Teff=16400K, set so BCv(5772K)=-0.085 => adopt BCv(B4V) = -1.49 [updated 4/4/2020, adjusted so that BCv(5772K)=-0.085] logL(B4V) = 2.892 dex ; Mv=-1.0, BCv=-1.49 mag => Mbol = -2.49 logL(B4V) = 2.802 dex ; logL/Teff trend for OB dwarf EBs (Torres10; Teff=16400K) => adopt logL(B4V) = 2.892 dex [updated 4/4/2020] => adopt Mbol(B4V) = -2.490 mag [updated 4/4/2020] Mass(B4V) = 5.75+-0.64 Msun ; Hohle10 Mass(B4V) = 5.314+-0.060 Msun ; Eclipsing binary V539 Ara B (Torres10) Mass(B4V) = 5.24 Msun ; Bertelli09 solar tracks Teff=16700K,logL=2.896 Mass(B4V) = 5.12 Msun ; Harmanec88 Mass(B4V) = 5.10 Msun ; EEM Teff vs. Mass fit for binaries (Teff=16700K) Mass(B4V) = 5.10 Msun ; EEM logL vs. Mass fit for binaries (logL=2.896) Mass(B4V) = 5.09 Msun ; Ekers18 ML calibration for logL=2.896 Mass(B4V) = 5.09 Msun ; MIST/Choi16 solar tracks logT=4.215,logL=2.892 Mass(B4V) = 4.969+-0.090 Msun ; Eclipsing binary V760 Sco A (Torres10) Mass(B4V) = 4.609+-0.073 Msun ; Eclipsing binary V760 Sco B (Torres10) Mass(B4V) = 4.47 Msun ; EEM Mv vs. Mass fit for binaries (Mv=-1.0) => adopt Mass(B4V) = 5.1 Msun [updated 4/16/2022] Rad(B4V) = 3.459 Rsun ; Teff=16400K, logL=2.892 => adopt Rad(B4V) = 3.459 Rsun [updated 4/4/2020] # Deprecated Standard 90 Leo = HD 100600 B3: Cannon B3V: Ahmed52 *B4V: Lesh68(stan, in Jaschek78) B5V: Johnson50 B6.6(IV): Kopylov58 Only listed as a B4V standard by Lesh68, but it appears to be nearly as hot and as blue as typical B3V standards. For this reason (and since only Lesh68 considered it a B4V standard), I listed it as a deprecated standard rather than a primary standard (even though it is the only B4V standard in the literature!). VanLeeuwen07 plx = 1.72+-1.15 mas, i.e. not well-constrained. Jaschek64 lists two B3Vs and a B5V. Weak pedigree. 3.5" sep par. A is ~B4V (V=6.3) and B is ~B8 (V=7.3). Mermilliod91: V=5.945, B-V=-0.155+-0.007, U-B=-0.638+-0.011 => updated Q-method (10/9/2011) => (B-V)o=-0.175, (U-B)o=-0.651, E(B-V)= 0.020, Av=0.064. Hauck97 photometry dereddened using Castelli91: (b-y)0=-0.110, c0=0.314, E(b-y)=0.042, Av=0.185. Teffs: 16347K(U-Bo=>Bessell98), 16628K(EEM, Hauck97 phot.=>Napiwotzki93 calibration), 16800K(Philip80), 17111K(EEM, Hauck97 phot.=>Balona94 calibration), 17115K(EEM, Hauck97 phot.=>BalonaShobbrook84 beta calibration), 18230K(Zorec09#2,Soubiran10), 18280K(Zorec09#1) => median Teff = 17111K. # Other Stars HD 103079 = HR 4549 *B4V: Jaschek78(Hiltner69),Houk75,Kennedy83 B4IV: deVaucoleurs57 B5: Cannon Jaschek64 lists 2 B4IV and 1 B5V. Pretty good agreement on B4 type by three expert classifiers (deVaucoloeurs, Hiltner, Houk). 1.5" binary. Johnson66 lists B-V=-0.11, U-B=-0.53. Neckel lists Av=0.24. Updated Q-method (10/9/2011) => (B-V)o = -0.150, E(B-V)=0.040, Av=0.143, (U-B)o = -0.558. Closest B4V star among stars in Skiff compendium with muliple (and majority) B4V classifications. Teffs: 14654K(U-Bo=>Bessell98). HD 91465 = HR 4140 = p Car B4Ve: Slettebak82 B4Vne: Hiltner69,Garrison96 B5Vnep: Jaschek65 Jaschek78 is a mess with 6 different types between B3V and B5III. Not standard material. HD 72436 = HR 3373 (J0831-3903) B4V: Hiltner69(B4Vp:),Garrison77,Corbally84(B4Vn) B5V: Feast55(B5Vn),Houk82 Decent agreement on B4V type by three expert classifiers: Hiltner, Garrison, Corbally. Companion B is 4.4" away (B7V; Corbally84), and C is 30" (F0:V:) Corbally84. # Stars with majority of classifications being B4V Although Garrison77 does not list a B4V standard, they classify 5 stars as B4V (or variant). The brightest are HD 72436 (V=6.5; B4V) and HD 153294 (V=8.3; B4V). HD 19736 = HR 950 HD 48383 = HR 2475 HD 56733 = HR 2769 ; Hiltner69, Thackeray73 HR 2871 ; HIltner69, Corbally84 (fainter of 9" cpm pair) HD 72436 = HR 3373 ; Hiltner69, Garrison77, Corbally84 HD 75112 = HR 3490 ; Hiltner69, Thackeray73 HD 103079 = HR 4549 ; Hiltner69, Houk75, deVaucouleurs57(B4IV) [Sco-Cen; 1.8" binary] HD 124367 = HR 5336 ; Hiltner69 (B4Vne), Slettebak82(B4Ve), Jaschek92(B4Ve) HD 137432 = HR 5736 ; deVaucouleurs57, Hiltner69 (B4Vp), Slettebak82 (B4V(e)), Jaschek92(B4V) HD 161573 = IC 4665 62 ; Gray02,Abt67,Abt64 None of these stars is within 100 pc. The closest is HD 103079 (plx=9.0+-0.5 mas; see above).