B0V Garrison94 lists the B0V anchor as Ups Ori (= HD 36512). However Sota11 considers Tau Sco as the B0V standard, and Ups Ori as an O9.7V star. Unfortunately there have been some subtle shifts at the OB boundary: MK43 JM53 Walborn72 MK73 MK78 Keenan85 Walborn90 Garrison94 Garrison96 Sota11 HD93027 ... ... O9.5V ... ... ... O9.5V ... ... O9.5IV Sig_Ori O9.5V O9.5V ... O9.5V ... ... ... ... ... ... Ups_Ori ... B0V B0V B0V ... ... B0V B0V ... O9.7V Tau_Sco B0V B0V B0.2V B0V B0V B0V B0.2V ... B0V B0V HD2083 ... ... ... ... ... ... ... ... ... B0.2V HD36960 ... ... B0.5V ... ... ... B0.5V ... ... B0.5V Bet_Sco B0.5V B0.5V ... ... ... ... ... ... B0.5V ... MK43 standard: tau Sco - B0V (with 139 Tau as "B0" standard) JM53 standards: tau Sco - B0V ups Ori - B0V del Sco - B0V HD 206183 - B0V HD 207538 - B0V Lesh68 standard: ups Ori - B0V tau Sco - B0V Garrison67 standard: HD 46106 - B0V [from Morgan65 "NGC 2244 Main Seq."] Abt68 standard: HD 46106 - B0V Hiltner69 standard: tau Sco - B0V Walborn72 standard: ups Ori - B0V (with Tau Sco as B0.2V) Houk75 standard: tau Sco - B0V (primary standard) Garrison77 standard: tau Sco - B0V MK78 standard: tau Sco - B0V Garrison79 standard: tau Sco - B0V Keenan85 standard: tau Sco - B0V Walborn90 standard: ups Ori - B0V (with Tau Sco as B0.2V) Garrison94 anchor: ups Ori - B0V GrayNstars standards: tau Sco & ups Ori - B0V Sota11 standard: tau Sco - B0V Garcia89 lists 4 B0V MK standards: HD 36512, 149438, 206183, 207538. Skiff08 lists two B0V standards: Hd 36512 (MK73) & HD 149438 (MK78). All UBV dereddenings in this file have been updated using a revised Q-method calibration (10/9/2011). B-V(B0V) = -0.32 ; JohnsonMorgan53 (with parentheses, i.e. uncertain) B-V(O9.7V) = -0.310 ; EEM dereddened ups Ori (was B0V, now O9.7V standard) B-V(B0V) = -0.301 ; from (U-B)o=-1.07 - trend with Q B-V(B0V) = -0.30 ; Garrison67,Fitzgerald70,Morgan71,SchmidtKaler82,KenyonHartmann95 B-V(B0V) = -0.30 ; Morgan53, Johnson63, JohnsonBorgman63,Johnson66 B-V(B0V) = -0.300 ; EEM dereddened N=5 B0V HIP stars (Q-method, E(B-V)<0.3) B-V(B0.2V) = -0.300 ; EEM dereddened B0.2V standard HD 2083 via Q-method B-V(B0.2V) = -0.297 ; EEM dereddened B0.2V non-standard tet Car via Q-method B-V(B0V) = -0.296 ; EEM dereddened primary standard Tau Sco* => adopt (B-V)(B0V) = -0.301 [updated 2/7/2020] The bluest B-V I can find for a B0V star is HIP 25923 (B-V = -0.261), so <(B-V)o> is likely to be bluer than that. U-B(B0V) = -1.055 ; EEM dereddened primary standard tau Sco (using Q-method)* U-B(B0.2V) = -1.057 ; EEM dereddened B0.2V non-standard tet Car via Q-method U-B(B0V) = -1.066 ; EEM dereddened primary stan. tau Sco (using logN_HI)* U-B(B0V) = -1.067 ; EEM dereddened N=5 B0V HIP stars (Q-method, E(B-V)<0.3)* U-B(B0.2V) = -1.068 ; EEM dereddened B0.2V standard HD 2083 via Q-method U-B(B0V) = -1.07 ; Bessell98 U-B(B0V) = -1.08 ; Johnson63, Johnson66, Fitzgerald70, Schmidt-Kaler82 U-B(B0V) = -1.10 ; JohnsonBorgman63 U-B(O9.7V) = -1.100 ; EEM dereddened O9.7V ups Ori (using Q-method) U-B(O9.7V) = -1.102 ; EEM dereddened O9.7V ups Ori using Lyalpha=>E(B-V)=>E(U-B) U-B(B0V) = -1.13 ; JohnsonMorgan53 (with parentheses, i.e. uncertain) => adopt (U-B)(B0V) = -1.07 *** [updated 2/7/2020] => adopt Q(B0V) = -0.854 [updated 2/7/2020] => adopt (V-Ks)(B0V) = -0.958 => adopt (V-J)(B0V) = -0.732 => adopt (V-H)(B0V) = -0.891 => adopt (H-K)(B0V) = -0.067 => adopt (J-H)(B0V) = -0.159 => adopt (V-I)(B0V) = -0.354 (Ks-W1)(B0V) = 0.016 ; EEM trend for d<30pc for B-V=-0.307 => adopt (Ks-W1)(B0V) = 0.016 [updated 12/29/2019] (Bp-Rp)(B0V) = -0.491 ; Evans18 trend for V-I=-0.354 (g-r)(B0V) = -0.59 ; Covey07 Teff(B0V) = 29000 K ; GrayCorbally09 Teff(B0V) = 29230 K ; Theodossiou90 Teff(B0V) = 29500 K ; Bohm-Vitense81 Teff(B0V) = 29800 K ; Bessell98 Teff(B0V) = 29800 K ; Blackwell80 Teff(B0V) = 30000 K ; Crowther97/Fig.3 Teff(B0V) = 30000 K ; Massey05(Milky Way) Teff(B0V) = 30000 K ; Schmidt-Kaler82 Teff(B0V) = 30300 K ; Chavez95 (+800-300K) Teff(B0V) = 30333 K ; U-B=-1.07 => Teff(Bessell98) Teff(B0V) = 30430 K ; Bertone04[ATLAS models] Teff(B0V) = 30705 K ; deprecated stan. HD 46106 (median Teff)* Teff(B0V) = 31125 K ; deprecated stan. HD 207538 (median Teff) Teff(B0V) = 31400 K ; pri. stan. tau Sco (median Teff) Teff(B0V) = 31480 K ; EEM N=33 Teffs* Teff(B0V) = 31783 K ; Q=-0.845 => Nieva13 calibration Teff(B0V) = 32000 K ; deprecated standard Ups Ori (median Teff) [now O9.7V]* Teff(B0V) = 32125 K ; deprecated standard HD 207538 (single Teff)* Teff(B0V) = 32359 K ; Simon-Diaz17 for B0V (N=1; HD 149438) Teff(B0V) = 33340 K ; Vacca96 Teff(B0V) = 33400 K ; deprecated standard HD 36512 (Nieva14) => adopt Teff(B0V) = 31400 K (logT = 4.497) [updated 1/20/2020] Mv(B0.5V) = -3.6 mag ; adopted Mv(B0V) = -3.13 mag ; pri. stan. tau Sco (see below) Mv(O9.7V) = -3.54 mag ; weak stan. ups Ori (see below) Mv(B0V) = -3.76 mag ; mean for 3 standards (tau Sco, ups Ori, HD 46106) Mv(B0V) = -3.85 mag ; Bowen08 Mv(B0V) = -3.9 mag ; Russeil03 Mv(B0V) = -3.95 mag ; Wegner07 Mv(B0V) = -3.97 mag ; logL/Teff trend for OB dwarfs (Teff=31500K,BCv=-3.00) Mv(B0V) = -4.0 mag ; Schmidt-Kaler82 Mv(B0V) = -4.1 mag ; GrayCorbally09 Mv(O9.5V) = -4.1 mag ; adopted Mv(B0V) = -4.21 mag ; Vacca96 Mv(B0V) = -4.62 mag ; weak stan. HD 46106 (see below) => adopt Mv(B0V) = -3.90 mag [updated 2/7/2020] => adopt M_Ks(B0V) = -2.942 mag = Mv - (V-Ks) = -3.90 - -0.958 [updated 12/30/2020] BCv(B0V) = -3.24 mag ; Vacca96 BCv(B0V) = -3.129 mag ; Flower96(Teff=31400K) BCv(B0V) = -3.03 mag ; Schmidt-Kaler82(BCv=-3.16 + 0.13 mag) BCv(B0V) = -3.026 mag ; Code76(Teff=31400K, set so BCv(5772K)=-0.085) BCv(B0V) = -3.014 mag ; Nieva13(Teff=31400K) BCv(B0V) = -2.995 mag ; Balona94(Teff=31400K, set so BCv(5772K)=-0.085) BCv(B0V) = -2.992 mag ; Bessell98(ATLAS9,logg=4.0,Teff=31400K, set so BCv(5772K)=-0.085) BCv(B0V) = -2.99 mag ; Bertone04[ATLAS models,their B0V Teff=30430K] BCv(B0V) = -2.975 mag ; LanzHubeny03/07(Teff=31400K,Z/Zsun=1,logg=4.0) => adopt BCv(B0V) = -2.99 [updated 1/20/2020] logL(B0V) = 4.31 ; pri. stan. tau Sco (see below) logL(O9.7V) = 4.47 ; weak stan. ups Ori (see below) logL(B0V) = 4.558 ; logL/Teff trend for OB dwarf EBs (Torres10; Teff=31400) logL(B0V) = 4.652 ; adopt Mv=-3.9, BCv=-2.99 => Mbol = -6.890 logL(B0V) = 4.683 ; logL/Teff trend for OB dwarfs (Teff=31500K) logL(B0V) = 4.91 ; weak stan. HD 46106 (see below) => adopt logL(B0V) = 4.652 dex [updated 2/8/2020] => adopt Mbol(B0V) = -6.890 mag [updated 2/8/2020] Mass(B0V) = 14.57 Msun ; Harmanec88 Mass(B0V) = 15.00+-2.83 Msun ; Hohle10 Mass(B0V) = 16.55 Msun ; EEM Teff vs. Mass fit for binaries (Teff=31500K) Mass(B0V) = 17.68 Msun ; EEM logL vs. Mass fit for binaries (logL=4.70) Mass(B0V) = 17.7 Msun ; MIST/Choi16 solar tracks for logT=4.497,logL=4.652 Mass(B0V) = 18.63 Msun ; EEM fit Mv vs. Mass to Torres10 binaries (Mv=-4.0) Mass(B0V) = 18.7 Msun ; Ekers15 ML calibration for logL=4.70 => adopt Mass(B0V) = 17.7 Msun [updated 4/16/2022] Rad(B0V) = 7.1580 Rsun ; logL=4.652, Teff=31400K => adopt Rad(B0V) = 7.158 Rsun [updated 2/8/2020] # No standard GrayAtlas does not list a B0V standard # Primary Standard HD 149438 = tau Sco = HR 6165 *B0V: Cannon(B0),MK43,Lesh68(stan),Jaschek78(JM53),Bertiau58,Jaschek64(all),Garrison67,Hiltner69(stan),MK73,Garrison77(stan),MK78,Garrison79(stan),Houk82,Keenan85,Garcia89,Garrison96,Sota11(stan) B0.2V: Walborn71,Walborn90 Tau Sco was considered B0V by most until Walborn71 called it B0.2V, but now it is considered B0V standard again by Sota11. The only B0V in Garrison96's table "The Brightest Stars". Hauck97 ubvy photometry => dereddened following Castelli91 => (b-y)o = -0.114, co = -0.094, e(b-y) = 0.021, T(Balona94) = 31048K, T(Napiwotski93) = 32689 K. Mermilliod91 photometry: V=2.825+-0.009, B-V=-0.252+-0.007, U-B=-1.023+-0.013 => Q-method(1/2020) => (B-V)o=-0.296, (U-B)o=-1.055, E(B-V)= 0.044, Av=0.143. VanLeeuwen07 lists plx = 6.88+-0.53 mas => 145+-11 pc (comensurate with its membership to Upper Sco OB association with d = 145 pc; de Zeeuw et al. 1999). Hence, Mv = -3.13+-0.17 mag, logL = 4.31+-0.07 dex. All Teff estimates: 28060K(Sokolov95), 28590+-526K(Fremat05#2), 28959K(Fremat05#1), 29374K(U-Bo=>Bessell98), 29640K(Zorec09#2), 29860K(Braganca12), 29920K(Malagnini,from Zorec09) 30000K(Snow94), 30000K(Glagolevskij19), 30400K(Smith10), 31000+-1000K(Martins11), 31048K(EEM via Balona94), 31400K(Kilian94), 31440+-2150K(Zorec09#3), 31500K(Hubrig08, cited in Lefever10), 31500K(Philip80), 31500K(Rauw12), 31800K(Remie82), 31900K(Mokiem05, cited in Lefever10), 32000K(Lefever10), 32000+-300K(Przybilla08), 32000+-300K(Nieva12), 32359K(SimonDiaz17), 32689K(EEM via Napiwotski93), 32710+-1690K(Zorec16), 33000K(Schonberner88) => median Teff = 31400K. Log(g) estimates: 4.05(Hubrig08, cited in Lefever10), 4.15(Mokiem05, cited in Lefever10), 4.2(Lefever10), 4.24(Kilian94), 4.3(Przybilla08, cited in Lefever10), 4.3(Przybilla08, cited in Lefever10). LogN_HI = 20.43+-0.10 (Shull85), 20.49+-0.04 (Bohlin78), 20.05 (Hobbs78). Adopting logN_HI = 20.46, and the Savage & Mathis (1979) logNH/E(B-V) = 4.8e21 atoms/cm^2/mag, then E(B-V) = 0.060. Then (B-V)o = (B-V) - E(B-V) = -0.252 - 0.060 = -0.312, and (U-B)o = (U-B) - 0.72*E(B-V) = -1.023 - 0.72*0.06 = -1.066. # Deprecated Standards Cl Trumpler 37 1588 = ALS 12008 *O9.7IV: Sota11 O9.7V: Mathys89 O9.5V: Conti71,Conti73,Conti74,Garrison76 O9III: Bisiachhi82, B0V: Morgan53,JM53,Morgan55,Hiltner56,Jaschek64(all),Simonson68,Garcia89 B3: Cannon Similar to HD 206183 -- Morgan called B0V, but others later moved to O9.5 or O9.7. OB2. M91: V=7.305+-0.014, B-V=0.324+-0.008, U-B=-0.640+-0.000 => updated Q-method (10/9/2011) => (B-V)o=-0.308, (U-B)o=-1.094, E(B-V)= 0.632, Av=2.047. Teffs: 32059K(U-Bo=>Bessell98), 32190K(Daflon03,Daflon07) => median Teff = 32125K. logg=4.32(Daflon07). vsini=39+-2 km/s (Daflon07). HD 36512 = ups Ori = HR 1855 *O9.7V: Sota11(standard) B0V: Jaschek78(JM53),Jaschek64(all but one),Lesh68(stan),Walborn71,Walborn72,MK73,Abt77(B0Vs),Garcia89,Walborn90,Garrison94,Houk99(Garrison),Russeil07 B0.5V: Lesh68(stan) B3: Cannon Considered B0V standard in many publications and by Walborn90 and Garrison94, but now considered O9.7V standard by Sota11 (Walborn is coauthor) [this is the only reason I've deprecated this now as a B0V standard]. Teffs: 31500K(Philip80), 31500K(Kilian94), 31560K(Cunha94), 31622K(Brown94), 31812K(Paunzen05), 32200K(LeBorgne03), 32340+-2200K(Zorec09), 32533K(U-Bo=>Bessell98), 32900K(Sokolov95) => median Teff ~ 32000K. logg=4.13(LeBorgne03), [Fe/H]=0.25(LeBorgne03). Ups Ori has the third bluest B-V in Johnson66's compilation of UBV photometry, and the 2nd bluest U-B, so it could be useful for defining the sequence of intrinsic UBV colors of hot stars. M91: V=4.618+-0.013, B-V=-0.264+-0.007, U-B=-1.068+-0.008. V=4.62 (Johnson66), V=4.618+-0.013 (Mermilliod91), B-V=-0.26 (Johnson66), B-V=-0.264+-0.007 (Mermilliod91), U-B=-1.07 (Johnson66), U-B=-1.068+-0.008 (Mermilliod91). logN_HI[cm^-2] = 20.35+-0.10 (Shull85; from Lyman alpha absorption). Adopting the Savage & Mathis (1979) logNH/E(B-V) = 4.8e21 atoms/cm^2/mag, the Shull85 logN_HI value translates to E(B-V) = 0.047. So (B-V)o = (B-V)obs - E(B-V) = -0.264 - 0.047 = -0.311. Then E(U-B) = 0.72*E(B-V) = 0.72*0.047 = 0.034 mag. So (U-B)o = (U-B)obs - E(U-B) = -1.068 - 0.034 = -1.102 mag. 10/8/2011: Using revised Q-method calibration on Mermilliod91 colors (B-V=-0.264+-0.007, U-B=-1.068+-0.008) => (B-V)o = -0.310, (U-B)o = -1.100, E(B-V) = 0.046, Av=0.146 mag. Vanleeuwen07 plx = 1.14+-0.25 mas => 877+-202 pc. I adopt D = 400 pc as typical distance to Ori OB1. The star is out of the plane and not particularly fast moving, so it is doubtful that it is much beyond Ori OB1, and is likely ~300-500 pc. Star seems to be associated with Ori OB1, but it is not among the belt or sword stars - it is a couple degrees SW of the Orion Nebula Cluster (ONC), but it does not share the motion of the hot stars near it. It could be a "slow" runaway star from the belt or sword region of Ori OB1. Its U and W motion are discrepent compared to the ONC (deltaU ~ +13 km/s, deltaW ~ -4 km/s). More work would be needed to test this idea. Adopting d=400 pc, then Mv ~ -3.54, logL ~ 4.47 dex. HD 46106 = HIP 31106 = Cl* NGC 2244 JOHN 5 (J0631+0501) O9.4(III): 1990AISAO..32..106P O9.7III(n): Sota14 O9.7II-III: Sota11 *B0V: Morgan65,Garrison67(stan),Abt68,Walborn71 B0.2V: Massey95,Wolff07 B0.5V: Morgan53,Johnson62 B1V: JM53 B1III: Voroshilov85 B2IIIn: Parthasarathy12 B8: Cannon Too much disagreement on type to be useful as a standard. Abt68 uses as B0V standard. Garrison67 adopts "NGC 2244 Main Sequence" from Morgan65 for B0-B2V standards, including Johnson #5, which includes HD 46106 as "B0V". Too much disagreement to consider a useful standard. Mermilliod91 lists V=7.927+-0.012, BV=0.145+-0.006, U-B=-0.755+-0.011 => revised Q-method (10/8/2011) => (B-V)o = -0.303, (U-B)o = -1.077, E(B-V)=0.448, Av=1.449 mag. VanLeeuwen07 plx = -1.92+-1.18 mas. NGC 2244 is the ionizing cluster of the Rosette nebula. Dias01 catalog lists D=1660 pc to this cluster. Hence, Mv ~ -4.62, logL ~ 4.91 dex. Teffs: 29150K(Daflon07), 30705+-539K(Fitzpatrick07), 30811K(U-Bo=>Bessell98) => median Teff = 30705K. logg=3.77+-0.16(Fitzpatrick07). HD 206183 = Cl Trumpler 37 171 = ALS 11933 *O9.5V: Cruz-Gonazalez74,Garrison76,Garmany82 B0V: JM53,Morgan55,Hiltner56,Simonson68,Garcia89 B9: Cannon (wow?!) It is not in the Maiz-Appelaniz O-star catalog. Post-1970 refs all agree on O9.5V. M91: V=7.419+-0.011, B-V=0.126+-0.012, U-B=-0.787+-0.005 => updated Q-method (10/9/2011) => (B-V)o=-0.309, (U-B)o=-1.100, E(B-V)= 0.435, Av=1.407. HD 143275 = del Sco = HR 5953 *B0.3IV: MK73,Houk88,Garcia89 B0V: JM53,Jaschek64(most),Slettebak68,Thackeray66(B0Vnk),Morris61,Bertiau58 B0: Cannon B0.5IV: Hiltner69,Jaschek78(Garrison67) B1V: Wilson50 B0IV: MK43. Originally B0V, but has been B0.3-0.5 since ~1970 I'm assuming the most authoritative classification is B0.3IV (MK73). Teff = 29760 K (Blackwell80). # Other Stars Lesh68 classified two stars as B0V: HD 202214 & HD 36512.