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19 64ApJ. . .139.1105T from anunpublishedlistkindlysuppliedbyG. Bakos.Fivesystemswereclassified lished reportsofBerger(1962),Bidelman(1958), and StruveFranklin(1955), servatory DoubleStarProgram.Otherthanthis, thedataweretakenfrompub- . Noattempthasbeenmadetotracethese databacktotheoriginalobserver expressly forthisstudybyA.Heiser,fromspectra takenwiththeKPNO36-inch of thesedatawerereceivedfromA.Slettebak(1963) andarepartofthePerkinsOb- a listofninety-foursystemsforwhichtheabovecriteriaweresatisfiedandwhich, with afewexceptions,goodspectraldatawereavailable forbothcomponents.Many betweenthecomponentsisgreaterthanabout2mag.Forsystemseven from theprimaryhasonmeasuresofsecondary,especiallyifdifferencein proved tobeconvenientforindicatingwhatmodificationstheequipmentand future. Systemswithsecondariesfainterthanabouttenthmagnitudewereexcluded closer than15",themajorproblemswhichwouldarisearemainlythoseassociatedwith the smallerdiaphragmsrequiredandwithguidingseeingdifficulties. It wouldalsobenecessarytoconductafairlycarefulstudyoftheeffectthatlight diaphragm (say,15")andtheobservationswerelimitedtonightsofverygoodseeing. ing theresults,itwouldseementirelyfeasibletoobserve,inaratherconventionalway, observing techniquemightbeneededbeforegoingtosmallerseparations.Afteranalyz- from thisstudy. (if differentfromtheauthorsnotedabove),and readerisreferredtotheindicated gained willmakeitpossibletoobservebinarieswithsmallerseparationsinthenear for theintrinsicseparationsofthesesystems were foundbetweenseparationandabsolutemagnitude.(4)Anupperlimitofabout40000a.uwas visional distances,intrinsicseparations,andperiodsweredeterminedforeachsystem.(3)Nocorrelations data, incombinationwiththespectralclassificationsavailableliterature,ledtoresultswhichcan those binarieswhichare15"ormoreapart,providedusewasmadeofasufficientlysmall only onthosesystemswithseparationsgreaterthan25",itishopedthattheexperience such systems,aphotometricstudyhasbeenundertakenattheDyerObservatorywith equipment andwerefreeofmostguidingseeingproblems.Moreover,thesesystems In ordertoextendthesestudiesandobtainphotoelectricmagnitudescolorsfor between themagnitudesandspectraltypesofcomponentsvisualbinarysystems be summarizedasfollows:(1)Goodconfirmationwasfoundforthetheoriesofcommonoriginandevolu- tion. Eachcomponentapparentlyevolvedasasinglestarwithoutclose-binary-typeinteractions.(2)Pro- the 24-inchSeyferttelescopeanditsassociatedequipment.Whilethispaperreports (Struve andFranklin1955;Bidelman1958;Stephenson1960;seealsoEggen1963). © American Astronomical Society •Provided bytheNASA Astrophysics DataSystem From theliteratureandfromprivatecommunications,ithasbeenpossibletoobtain It wasfoundthatsystemswiderthan25"wereeasilyobservedwiththeavailable In recentyears,severalstudieshavebeenundertakentoinvestigatetherelationship * PresentAddress:KapteynAstronomicalLaboratory,Broerstraat 7,Groningen,TheNetherlands. Ninety-four visualbinarieswithseparationsgreaterthan25"wereobservedinthreecolors.These A UEVSTUDYOF94WIDEVISUALBINARIES Received August5,1963;revisedJanuary20,1964 Dyer Observatory,Nashville,Tennessee Charles RayTolbert* II. THESPECTRALDATA I. INTRODUCTION ABSTRACT 1105 19 64ApJ. . .139.1105T reports foracompletediscussion.MostofthepresentdataareonMKsystem,but measured asstandardreferencestars.Sincethesestarsweresubjectedtothe of another,eventhough,insomecases,slightdifferenceswereevident. it wasnotthoughtadvisabletoadjustthedataofanyoneobserveragreewiththat result thatthedifferentialmeasuresembodylesserrorthanmagnitudesandcolors. found amongthedataforeachofninety-foursystemsandshowclearlyexpected ing asunknownsfourteenUBVstandardstarsselectedatrandomfromamongthose reduced tothestandardUBVsystem.Table1givesasummaryofrmsdevia- mag. Nomeasurablecolordependencewasfound. Duetosuchlargescatter,thecorrec- placed invariouspositionsnearabrightstar.CurvessimilartothoseFigure1were factors, astudywasmadeofthelightscatteredinto22"diaphragmwhenit large differentialmagnitudesandsmallseparationscombinedtoproducesystematic with asingleobservation.Bothsetsofinternalerrorsareaveragesthedeviations nearly aspossiblewiththoseofJohnsonandMorgan(1953).,allthemeasureswere usual method,fiveorsix standard extinctionstarswereobservedatvarious airmasses measured frequentlyduringthenightandwere usedtofollowthevariationof from atleastthreeseparatemeasuresmade,when possible,onseparatenightsand remove thesystematicerrorspresent.Noneof othereighty-eightsystemsneeded per cent,butwereneverthelessappliedtothesix systemslistedinTable2orderto obtained forF,B,andUmagnitudes,butthey containscatteroftheorder±1 sible toremovethecontributionofinternalerrorsandobtainanestimatesolely same internalobservationandreductionconditionsasthebinarysystems,itwaspps- of MorganandJohnsontothenaturestellarspectra,weredeterminedbytreat- These differentialsarenotinfluencedasstronglybythoseerrorswhicharisefrom on oneortwooccasionsduring eachnight,andfromthesedataitwaspossible todeduce cation tothenormaltechnique forextinctiondeterminations(Hardie1962). Asinthe tied intoavarietyofUBVstandardstars.These standardreferencestarswere tion factorsdeterminedfromthesecurvesinvolved possibleerrorsofasmuch50 contaminated bythelightofcompanion.Therewere,however,afewsystemswhere which was,inmostcases,abletoisolateeachcomponentsothatitsmeasureswerenot the externaldeviations,andtheyaresotabulated. atmospheric- fluctuationsandseeingvariations. tions inthereduceddata,indicatingbothexternalandinternalerrorsassociated the averageextinctioncoefficients andtheequipmentzeropoints,including theadjust- extinction coefficients.Itwaspossibletoaccomplish thisbyapplyingaslightmodifi- correction byasmuch0.01mag.ineitherF,JB, orZ7. errors inthedataoffaintercomponent.Todetermineappropriatecorrection 1106 CHARLESRAYTOLBERTVol.139 © American Astronomical Society •Provided bytheNASA Astrophysics DataSystem The photocellandfiltercombinationsusedinthisstudywerechosentocoincideas The externalerrors,whichareduetoinexactmatchingofthecellandfiltersthose All theobservationsweremadeusinga22"diaphragm,locatedinfocalplane, With onlyacoupleofexceptions,allthemagnitudes andcolorslistedwerederived Magnitudes andcolors(external) Magnitudes andcolors(internal) Differentials (internal) Rms DeviationsperSingleOsservation III. THEPHOTOMETRICDATA TABLE 1 ±0 010 ± 015 ±0 022 ±0 009 ± 012 +0 007 B—V ±0 012 ± 018 ±0 021 U-B 19 64ApJ. . .139.1105T liable. Aweightingfactorof2or3wasusedindetermining theaverages,dependingon This techniqueallowedgooddifferentialdeterminations aswellmagnitudesand cases, themeasuresofasystemwereinterlaced between thecomponentsasfollows: averages ofalltheobservationswithappropriate weightingfactorsapplied.Inmost color dependencewasfound. spikes producedbythesecondarysupportvanes.Lowercurvemeasuredbetweenspikes.Nomeasurable diaphragm asafunctionofdistancefromthecentralimage.Uppercurveobtainedondiffraction without regardtowhether theywerefoundtobephysical. whether themodeofobservation yieldedbetterdifferentialsormagnitudes and a singlestar,andthedifferentialsobtainedfrom thesedataareconsequentlylessre- colors. Insomecases,however,eachcomponentwas measuredcompletelyasifitwere colors. value. fore, tointerpolatethesevaluesoverthenightratherthanattemptuseanaverage No. 4,1964WIDEVISUALBINARIES1107 on occasionwouldchangebyasmuch±0.10mag.ormore.Itwasdecided,there- coefficients wouldvaryabout±0.05mag.duringtheseveralhoursofobserving,and , usingthepreviouslydeterminedzeropoints.Onanaveragenight,extinction ments tothestandardsystem.Sincethereisreasonexpectzeropointsbemore Fa, VByBb,BaiUAyU(inwhichthesubscriptsrefer tothecomponentsofbinary). were determinedfrequentlyduringthenightfrommeasuresofstandardreference nearly constantoveraperiodoftimeratherthantheextinctioncoefficients,latter b © American Astronomical Society •Provided bytheNASA Astrophysics DataSystem The listedmagnitudes,colors,anddifferentialmeasures foreachsystemarethe Table 3isacompilation of thepertinentdataavailableforninety-four systems Fig. 1.—Anillustrationshowingthedecreaseinmagnitudeoflightscatteredintoa22" ADS 12913 ADS 12197 ADS 10786 ADS 8695 ADS 2157 ADS 513 System Corrections AppliedtotheSecondaryToAdjustfor Contamination fromthePrimary +0 01mag. -j- 01mag. -j- 03mag. -j- 02mag. -j- 02mag. +0 01mag. TABLE 2 + 0 00mag. 00 mag. 04 mag. 00 mag. 01 mag. +0 02mag. + 01mag. + 06mag. — 01mag. U-B 19 64ApJ. . .139.1105T 1 Y\Tau. A ADS A ADS A 4188 B ADS A ADS A ADS A 4262 B 4134 ADS ADS A 4182 B 4000 B 3962 B 3910 B ADS A 2313 B BDS A ADS A 3579 B eTau. ADS A ADS A BDS 3317 B O^Tau. 3179 B ADS A ADS A 3085 B ADS 2157 B BDS 1731 1982 B ADS ADS ADS ADS 1753 ADS A ADS 899 513 1094 1563 1073 903 1459 B © American Astronomical Society •Provided bytheNASA Astrophysics DataSystem B 7.18 6.43 5.07 6.40 5.68 4.78 6.85 2.22 8.38 7.18 6.55 6.36 7.60 6.10 7.16 4.28 7.82 6.55 5.00 4.26 3.85 3.41* 8.18 6.36 7.44 6.95 6.34 2.87 7.87 8.51 7.09 6.30 3.77 6.50 6.00 7.17 7.32 7.25 8.61 4.36 9.60 4.77 6.56 6.35 6.47 6.94 4.99 5.56 5.34 9.17 -.04 -.11 -.12 -.10 -.15 -.12 -.16 -.09 -.13 -.22 -.25 -.22 1.12 -.13 B-V 1.68 1.10 2.05 -.06 -.01 .06 .48 .05 .06 .55 .18 .95 .18 .34 .01 .15 .17 .70 .59 .09 .04 .14 .51 .42 .27 .30 .24 .57 .30 .40 .49 .40 .19 .14 .23 .69 -1.00 -.68 -.89 -.87 -.14 -.39 -.91 -.99 1.16 -.28 -.30 -.56 -.38 -.05 -.08 1.85 U-B -.03 2.30 -.02 -.05 -.07 -.17 .09 .62 .84 .44 .58 .04 .03 .07 .35 .22 .04 .09 .00 .19 .01 .16 .79 .08 .08 .38 .07 .09 .08 .54 .07 .42 ,72 ,13 .00 ,00 ,18 ,03 ,06 ,06 .06 .04 .18 .05 .00 .05 .35 .00 .04 .00 .25 .14 .00 .07 ,47 ,00 ,03 00 TABLE 3 1108 B9.5 B7 BO. 5 B2 Kip III-IV 09.5 B1 BO. 5 F6 V B1 09.5 B3 B5 AO pec, B6-7 B7-8 KO Al B3 F8 A7 AO-1 B4-5 BO G8 B7 K3 GO A3 A1 B9 F6 F4 B5 A4 G2 Am K5 B6 F6-7 B9 AO A5-6 A5 GO F2 AO F3-5 FO Spectral Type lab-lb III III III III III III III II IV IV IV IV IV IV IV V V V V V V V V lb Parallax '.•030 y029 I'025 m -M (±.38) (±.96) (±.63) (p.e.) 2.61 2.68 3.01 v 1&2,CRV * 1&2,CPM,CRV 3,A Close 1,CRV,A Spec, 1&2,CPM 1,CPM,CRV * 2, * 1 ,CPM 1,CPM,A Spec, 2, CPM 1, C PM,CRV * 1,CPM,CRV * 5,0ptical * 1, C PM,CRV 1, * 1» * 3, CPM 1,CPM,CRV 6 2,0PM,A Spec, 2, CPM,CRV * 6 5,Optical * 1, * 1,CPM,CRV * 1, CPM,CRV 1&2 A Spec. A Spec. A Spec. A Spec. Comments 19 64ApJ. . .139.1105T ADS ADS ADS A ADS ADS A ADS A ADS 8568 B 8530 8470 B ADS A BDS 8695 8347 ADS A ADS A ADS A HR A ADS A BDS ADS A 7654 B 7438 B 7311 B ADS A ADS A ADS A ADS BD +31‘ ADS A 8735 B 8162 B 5652 8001 B 7967 B 3590 B ADS A ADS A ADS A 8883 B 6988 B 6913 B 6783 B 6617 6498 6028 C 5103 B 4749 B 6588 B 1676-7 Star © American Astronomical Society •Provided bytheNASA Astrophysics DataSystem 4.79 4.91 6.63 8.55 8.78 6.89 7.03 6.54 7.56 6.49 7.12 4.79 7.25 7.04 7.36 7.06 5.28 9.50 6.22 9.74 7.15 8.95 8.13 8.07 7.19 6.06 4.02 8.41 8.71 6.10 6.76 6.95 6.57 7.70 4.36 7.82 4.17 6.93 5.72 6.66 1.80 1.36 9.41 8.80 7.93 7.75 6.86 7.36 8.00 6.23 B-V -.04 1.13 -.12 1.03 1.08 1.14 1.20 1.10 -.03 -.06 1.00 1.42 .02 .11 .74 .91 .23 .53 .57 .51 .80 .87 .52 .55 .90 .44 .36 .31 .04 .99 .60 .40 .38 .83 .78 .54 .45 .40 .90 .81 .65 .18 .32 .03 .07 .96 .18 .30 .10 .13 U-B 1.07 -.13 1.12 1.25 -.03 1.03 -.01 -.49 -.06 1.72 -.08 -.12 -.00 .09 .05 .01 .08 .34 .02 .26 .38 .04 .01 .68 .93 .49 .03 .89 .59 .52 .36 .04 .66 .04 .03 .77 .09 .02 .00 .51 .00 .45 .77 .18 .71 .06 .09 .04 .04 .05 TABLE 3-Continued S-, ,00 ,00 ,00 ,00 ,00 ,00 ,00 ,00 ,00 ,00 ,00 ,00 ,00 ,00 ,09 ,06 ,00 ,00 ,00 ,00 ,00 ,00 ,00 ,00 00 K2 KO A3 F2 K2 GO G3 G8 AOp GO F5 F8 A2p KO II-III KI II-III B5-6 F3 F7 F7 V KO KO B7 F5-6 F2-3 G8 F3 IV A3 K2 B9-A0 B9 Fl-2 A2 AO V AO-1 III-IV GO F5 G8 A5-6 IV A6-7 III-IV FO-1 G2 G2 Spectral 1109 Type IV-V III III III III III III III IV IV IV IV IV IV V V V V Vb V: lb Parallax '.'053 '.'0Z1 '.'039 m -M (p.e.) v (±.28) (±.40) (±.36) 1.38 2.54 2.03 2, * 5,A Spec.* 4, CPM 5,CPM,CRV 5,B Close,Optical 3, A Close 1,CPM,CRV * 1,CPM,CRV * 3,CPM,A Close 2, CPM,AClose 2,CPM,A Spec. 1,CPM,CRV 3, C PM * 1 ,CPM 2, * 1,CPM,CRV 2, * 6,CPM 2CPM,B Close 1&3,CPM,B Close t B Close A Close CPM,CRV B Close CPM,CRV B Close CPM MK Std.,Optical* Comments 19 64ApJ. . .139.1105T ADS A ADS A 7300 B HR A ADS A ADS A ADS A ADS A 12750 B 12693 B 12197 B ADS A 11639 D ADS A ADS A HR A 11593 B 11336 C ADS A ADS A 10966 C ADS A ADS A 10759 B ADS A ADS A 10786 B 6575 B 10635 B aLib. B 10628 B 10535 B 10129 C ADS A ADS A 10149 B 10022 B ADS A ADS A ADS A HR A 9951 C 9626 B ADS A 5114 B 9559 B 9474 B 9277 B 9258 B 9-8 A Star © American Astronomical Society •Provided bytheNASA Astrophysics DataSystem 6.40 8.29 9.47 5.64 7.66 4.31 5.57 8.58 4.37 5.70 8.05 7.88 4.98 6.46 8.12 3.95 3.42 5.79 4.58 7.74 7.81 9.76 5.81 4.91 4.87 6.27 5.78 9.97 6.28 6.93 5.53 5.08 3.76 4.03 9.57 6.30 6.50 4.29 7.82 3.46 7.64 5.15 7.62 7.12 6.62 8.94 6.84 6.98 2.75 6.49 2.07 1.05 1.09 -.15 -.05 -.12 -.02 1.52 1.05 -.01 -.06 -.03 B-V 1.09 -.02 1.04 .26 .49 .08 .08 .31 .22 .08 .50 .03 .77 .54 .45 .42 .30 .03 .32 .28 .46 .89 .13 .29 .14 .07 .60 .32 .41 .59 .30 .32 .14 .12 .13 .48 .00 -.33 2.33 -.18 -.06 -.64 -.25 -.56 -.04 -.57 -.60 -.01 -.01 -.02 -.08 -.16 -.16 U-B -.38 -.64 -.01 -.02 -.02 -.04 .02 .78 .86 .06 .14 .02 .98 .35 .02 .05 .82 .05 .03 .06 .53 .08 .93 .15 .12 .04 .02 .66 .02 .03 .10 .07 .08 .91 TABLË 3-Continued ,02 ,03 ,00 ,04 ,00 ,00 ,00 ,00 ,04 ,20 ,00 ,00 ,08 ,00 ,00 ,00 ,00 44 11 04 31 00 00 00 mo dM4 B3 V MO lab-lb G8 A1 B4-5 G5p Al-2 B8 B3 FO A1 B5 B3 G5 F8 KO F5 F4 FO A2 FO G5 AO Am A5 B9.5 B9 A9 B9p B2 A4 G1 F2 A3 AO AO A2 F6 K1 FO GO G8 FO F2 Spectral Type III III III III III III III II IV IV IV IV IV IV IV IV V V V V V V V V Parallax '.'025 yo3i y 108 '.»046 y026 yoso y028 I'045 (±.44 -0.16 (±.50) m -M (±.12) (±.24) (±.52) (±.44) (±.48) (±.56) (p.e.) 3.01 2.54 2.92 1.68 2.61 2.76 v 1.68 5,Optical * 3 2,Optical * 1&2,CPM,CRV * 1,CPM * 1&2,CRV,A and 3,CPM,CRV 1,A Close 1,CPM,CRV * 3, CPM 1,CPM,CRV 1,CPM * 5,Optical * 1,CPM,CRV * 1,CPM,CRV 1,CPM,A and 1,CPM,CRV 3,CPM 1,CPM,CRV 1,CRV * 1,CPM,B Close 1,CPM * A Spec. C Close B Close A Close B Close C Close Comments 19 64ApJ. . .139.1105T ADS A ADS A ADS A ADS A ADS A ADS A 16633 B 16611 B ADS A ADS A ADS A ADS A ADS A ADS A 16481 B 15764 B 15434 B 14720 C ADS A 14909 B 14636 B ADS A ADS A 15147 B 14345 B 14101 C 13870 B BDS A ADS A ADS A ADS A 13554 C 13379 B 13087 B 9705 B 12815 B 12913 B 12767 C Star © American Astronomical Society •Provided bytheNASA Astrophysics DataSystem 10.30 4.23 8.18 7.55 9.18 6.74 8.49 6.10 7.67 9.52 6.66 5.76 7.29 6.19 4.08 6.45 8.50 9.19 6.04 5.22 6.51 5.05 8.40 6.37 7.14 6.99 3.76 7.59 6.48 5.70 7.32 7.13 8.53 5.95 8.14 4.96 6.21 5.30 1.12 -.01 -.37 1.06 1.04 -.15 1.55 1.38 1.13 1.21 -.14 1.63 B-V 1.29 -.04 -.08 1.14 1.06 .69 .56 .09 .15 .37 .02 .85 .01 .92 .72 .58 .10 .02 .13 .18 .31 .14 .50 .56 ,67 69 2. J.Berger(1962) 6. A.Heiser(PrivateCommunication) 5. G.Bakos(PrivateCommunication) 4. 0.StruveandK.L.Franklin(1955) 3. W.P.Bidelman(1958) 1. A.Slettebak(1963) -1.00 1.00 -.03 -.25 -.62 -.86 -.01 -.01 -.35 1.38 -.02 1.04 1.24 1.14 1.63 -.58 U-B -.26 -.48 -.01 1.06 .11 .92 .07 .84 .54 .68 .24 .01 .06 .44 .02 .07 .05 .03 .91 .19 .17 .07 TABLE 3-Continued ,00 ,00 ,00 ,21 ,00 ,00 ,00 ,00 ,09 ,00 ,00 ,06 ,00 ,00 \-V 14 14 18 dK6 dKl KO GO F7 B8 B3 KO Bl BO. KO A3 Al M5 K7 K5 G5 F2 K1 B5 A2- A2- B5 B6 M3 A3 A1 B8 F8 A1 K2 G5 F6 K2 F5 G2 Spectral mi II +B3V Type II-III II-III IV-V III III III III IV IV IV V V V V V V V Parallax , '.'292 .034 '.•030 '.'047 m -M -2.33 (±.03) (±.31) (±.68) (±.24) (p.e.) v 2.34 2.61 1.63 3,CPM,CRV 6,CPM,CRV 2 3 3,CPM,CRV 1,CPM * 1,CPM * 1,A Close 1,CRV * 6 5, * 6, CPM 3,CPM 5, CPM,CRV 1,CPM * 1,CPM,CRV 1 ,CPM 1,CPM,CRV B Close Conunents 19 64ApJ. . .139.1105T indicates aremarkinthenotesthatfollowhere. and “Close”indicatethecomponentisaspectroscopicorclosebinarysystemitself,{d)anasterisk(*) “CPM” and“CRV”refertocommonpropermotionradialvelocity,respectively,(c)“Spec” sibly inerrororsystemmaybeoptical. error orsystemmaybeoptical. spectral datamaybeinerror.Systemprobablyphysical. System probablyoptical. probably discordant.Systemlikelyphysical. but systemlikelyphysical. error orsystemmaybeoptical. cal (seereddeningdiscussion),butithasCPM.Physicalrealityindefinite,willassumephysical. 6617. See alsoADS6617. tral type.P.M.andR.V.indicatesystemprobablyphysical. Physical realityindefinite,butwillassumephysical.Useaverage reddening,E-v=0.43. Use reddeningofsecondary:E-v=0.02. (Strand 1957a). B B © American Astronomical Society •Provided bytheNASA Astrophysics DataSystem The arrangementofthetableshouldbeclearwithpossibleexceptionfollowing: ADS 513.—determinedfromtheluminositycalibrationis0.7mag.Spectralclassificationpos- ADS 903.—StruveandFranklin(1955)listF4VF6forcomponents. Col. (10)comments:{a)thenumberreferstospectralobservernotedatendoftable,(b) Col. (9)distancemodulusdeterminedfromtheparallaxandprobableerrorassociatedwithit. Col. (8)trigonometricparallaxfromtheYaleCatalogueifgreaterthan0''025. ADS 1753.—kMvdeterminedfromtheluminositycalibrationis1.5mag.Dshowsrelativemotion. BDS 1094.—Twospectravisibleforsecondary. ADS 1563.—Berger(1962)listsA9-F0IVandF7-8Vforcomponents. ADS 1459.—Seereddeningdiscussion. ADS 4134.—Berger(1962)listsB3Vforsecondary. ADS 4749.—SlettebaklistsprimaryasAlV(shell). ADS 4262.—See3579. ADS 3579.—P.M.slightlydifferent;however,systemlikelyphysical. BDS 1731.—P.M.andR.V.bothsomewhatdifferentforthecomponents.Systempossiblyoptical. ADS 6617.—PairnotedasopticalbyBidelmaninprivatecommunication. BD +31°1676-7.—kMdeterminedfromtheluminositycalibrationis—1.0mag.;however, ADS 4188—See3579. BDS 2313.—Berger(1962)listsB5-6VandA2-3forcomponents. ADS 8347.—Berger(1962)listsAl-2VandAO-1forthecomponents. HR 3590.—determinedfromtheluminositycalibrationis3.6mag.Spectraldatamaybein 0 Tau.—Hyadesclustermembers.SpectraldatafromSlettebak(privatecommunication). ADS 8735.—AMdeterminedfromtheluminositycalibrationis0.6mag.Systemprobablyoptical. ADS 8568.—Berger(1962)listsA7-9Vforsecondary. ADS 8530.—&.Mdeterminedfromtheluminositycalibrationis0.9mag.Spectraltypeofprimary y] Tau.—InPleiades.SpectraldatafromSlettebak(privatecommunication). ADS 10149.—Berger(1962)listsA2-3IVandA2Vforthecomponents. ADS 7438.—See3579. ADS 10635.—Berger(1962)listsA2-3IVandA7-9Vforthecomponents.R.V.slightlydifferent, ADS 10022—See6617. ADS 9474.—Berger(1962)listsF0IVforsecondary. ADS 9277.—P.M.slightlydifferent,butR.V.measuresingoodagreement.Systemphysical. ADS 14345.—AA/i,determinedfromtheluminositycalibrationis5.5mag.Spectraldatamaybein ADS 13554,—Bidelman(1954)alsolistsK2II+B3Vforprimary.Reddeningindicatessystemopti- ADS 12693.—Reddeningdiscordant.P.M.notcommon.Systemoptical.Seealso6617. ADS 12197.—BothP.M.andR.V.differbetweenthecomponents.Systemoptical.Seealso ADS 11639.—StruveandFranklin(1955)listdA9A3nforcomponents. ADS 15434.—Reddeningindicatessystemoptical(seereddening discussion),butithasCPM. ADS 15147.—Berger(1962)listsA2-3VandFl-2forthe components. ADS 14720—Seereddeningdiscussion. ADS 14636.—StruveandFranklin(1955)listdK6dMO forcomponents.Orbitdataavailable ADS 16633.—&Mdeterminedfromtheluminositycalibration is8.2mag.Possibilityofwrongspec- ADS 16611.—StruveandFranklin(1955)listdFdG2 forcomponents. v V V V NOTES TOTABLE3 1112 19 64ApJ. . .139.1105T mined fromthespectraldataandArp’s(1958)calibrations(seediscussiontofollow) ponents ofabinarysystemshouldbereddenedsimilarly. Whiletherewasthepossibility reduced byreferringtothespectraldatafor star andbyassumingthatbothcom- reddening arisingfromthepositionofsomestarsin thecolor-colordiagramweregreatly likely tobeoptical. the data,absorptioninVwastakentobe3 Eb-v- Thewell-knownambiguitiesin to within±1.5mag.,thesysteminquestionisdiscussednotesTable3. comparing thedataforbothcomponentswithcolor-colorcurveslistedbyArp that largereddeningdiscrepanciesweretreated as indicationsthatthesystemswere that thecomponentsmightbedifferentiallyreddened, thiswasconsideredsoslight optical. spectral typeisAOIII,and itappearsreddenedbyabout0.25mag.System probably both fromitsspectraltype anditspositioninthecolor-colordiagram.The secondary’s are discussedasfollows: (1958). Areddeningslopeof0.72wasassumedinallcases,andforthelateranalysis © American Astronomical Society •Provided bytheNASA Astrophysics DataSystem The reddeningcorrectionforeachoftheninety-foursystemswasdeterminedby Where thedifferentialmagnitudesdonotagreewiththosewhichwouldbedeter- The severalbinarieswhichrevealedsuchdiscrepancies areshowninFigure2and ADS 1459.—TheprimaryisaK5lbandappearsquite reddened(E-v=0.55mag.) B WIDE VISUALBINARIES1113 IV. THEREDDENING 19 64ApJ. . .139.1105T differential absolutemagnitudes (Aikf)derivedfromthespectraldataand fromArp’s ,etc.,todeterminethephysicalreality ofsuchsystems. indicated. necessary, therefore,toconsiderotherparameters aswell,suchpropermotion, binary system,thereddeningwillappearaccordant evenifthesystemisoptical.It grater than1.5mag.are(1)BD+31°1676-7,(2)ADS8735,(3)513,(4)8530,(5)1753, a systemisoptical,similarreddeningnotan indication thatasystemisphysical. ary (BlV)isreddenedbyonlyEb-v—0.32.On thebasisofcolors,therefore, for thesecondary.Theprimaryhasacompositespectrum(K2II+B3V).Byusing was determinedfromthespectraldataandluminositycalibration.Thosesystemswithdeviations Manifestly, iftheobscuringmatterisbetween the Sunandbothcomponentsofa assumed physicalandthereddeningofprimaryadopted. B8 (HDE231829),anditappearsquitereddened.Systemprobablyoptical. late-type stars,andthe(B—V)coloragreeswellwithspectraltype.System dening inrelationtothestar’sactualpositiondiagram.Onbasisof be roughlyB—F=0.3andU—0.4whichwouldimplyconsiderablered- the luminosityandcolorcalibrationsgivenbyArp(1958),compositecolorswould (6) ADS13554,(7)HR3590,(8)14345,and(9)16633.Thevariousspectralobserversare colors, therefore,thesystemappearsoptical,butseenotestoTable3. the systemappearsoptical,butseenotestoTable 3. 1114 CHARLESRAYTOLBERTVol.139 v (M5 III)appearsdiscordant.However,theclassIIIcurveispoorlydefinedforthese © American Astronomical Society •Provided bytheNASA Astrophysics DataSystem ADS 15434.—Theprimary(B0.5V)isreddened byEb-v=0.54,butthesecond- Figure 3isacomparison ofthephotoelectricdifferentialmeasures(&m ) withthe It shouldbepointedoutthat,whilediscrepantreddening maybeanindicationthat ADS 13554.—Boththespectralandphotometricdataindicateonlyslightreddening ADS 12693.—TheprimaryisG8IIIandonlyslightlyreddened.Thesecondary ADS 14720.—Theprimary(B5V)isreddenedbyE-v=0.14,andthesecondary Fig. 3.—Comparisonofdifferentialmagnitudes.àmwasdeterminedphotoelectrically,while&M v B vV v. DISCUSSION 19 64ApJ. . .139.1105T observers areasfollows: differential color. Wallenquist’s datatothestandardsystembecausetheyhadaninsufficientrangein differentials. ThescatterwithrespecttoWallenquist^dataisnodoubtdue,partly, quist andbyJohnson.Thedifferencesareplottedagainstthepresentdata. present case,sincetheproblems inherentinitarereducedwiththegood placed themonthemain sequence.Thistechniquecanbejustified,somewhat, inthe diagram, foritisonlyherethatonemayrelate the theoriesofstellarevolutionwith to itsnotbeingreducedtheUBVsystem,whichwouldalsoaccountforin- the assumptionsofcommonorigin.Toaccomplish thisinvestigation,itwasassumed crease inthedifferenceswithincreasingdifferentials.Itwasnotpossibletoconvert that allthesecondariesofluminosityclassVhad absolute magnitudeswhichrigorously classifications whichare available andtheunambiguousdeterminations of theinter- arately inthenotestoTable3.Thefactthatmostofdatafallwithinboundary Wallenquist (1958)andJohnson(1953).Thedeviationsareplottedagainstthepresent relative tothemainsequence(Stephenson1960). luminosity classes,assuchdatawouldallowbettercalibrationsofthehigherclasses electric studiesofsystemswithgoodspectraldatawhichcoverawidervariety improvements inthecalibrations.Itwouldbeveryusefultopursuesimilarphoto- lends credencetotheluminositycalibrations,atleastwithin±1.5mag.Unfortu- allowed, andallsystemswhichexceededthisboundarywerenoteddiscussedsep- vestigate this,anarbitraryrangeof±1.5mag.(about1standarddeviation)was No. 4,1964WIDEVISUALBINARIES1115 nately, thepresentdatadonotcoverasufficientrangeinluminosityclassestoallow mean duetothehigherprobableerrorsofspectralclassifications,inaccuraciesin the calibrations,etc.,verylargedeviationsmightwellindicateopticalsystems.Toin- (1958) luminositycalibrations.Whileitisnaturaltoexpectsomescatteraboutthe45° 1 © American Astronomical Society •Provided bytheNASA Astrophysics DataSystem The averagedeviationsfoundinthedifferentials inrelationtothevariousother It isofdefiniteinteresttoinvestigatethelocation ofthesebinarysystemsinaH-R Fig. 4.—DifferencesindifferentialmagnitudesbetweenthepresentdataandthoselistedbyWallen- Figure 4isacomparisonofthepresentdifferentialmagnitudes(km)withthose v -¿- DIFFERENCES ♦.2 -.1 • so (MAS.) Present dataversusWallenquisPs... . ±05mag. Present dataversusthespectral... ±0.80mag. Present dataversusJohnson’s...... ±002mag. • PRESENTDATAMINUSJOHNSON'S O PRESENTDATAMINUSWALLENQUIST'S I o o VI. EVOLUTIONARYEFFECTS o * AM. £ L O — 19 64ApJ. . .139.1105T 12 12 for thosesystemswithclassIV,III,orAm-typesecondariesinrelationtotheir maries fromthedifferentialmagnitudesandcolors.Asimilarassumptionwasmade stellar reddening.Itwasthenpossibletolocateaccuratelythepositionsofpri- it willbenecessarytouse thedistanceswhichweredeterminedthere.These distances, depends stronglyonthevalidity oftheassumptionsmadeinprevious section, since more extensiveandreliablephotometricdatamade availablehere. regarding evolutionaryeffectsare,therefore,well supportedandconfirmedbythe fall withintheuncertaintiesofevolutionarypredictions. Itcannotbesaidwhether have beenstudied,itwouldnotseemprudentto attach toomuchsignificancetothem. . However,sincethesearetheonlytwo casesfoundamongthemanywhich Jaschek and(1959).Thesequenceswereallslightlyidealizedtostraight-line appropriate luminositysequence.Thesequencesusedweretakenfrom or ofstarsevolvingoffthemainsequenceinamanner notquiteproportionaltotheir this conflictisevidenceofverybrightstarsbecoming slightlyfainterastheyevolve cant thatthedifferentialmagnitudesforthese two binariesaresmallandprobably binary system,theyarephysicallyrelated,andtheconflictwouldremain.Itissignifi- members oftheHyades(JohnsonandKnuckles1955),eveniftheyarenota primary. Sincethissituationisinconflictwiththepreviouslystatednotionofevolution, segments forconvenienceinplotting. Arp (1958),withtheexceptionofthatforAm-typestarswhichwastakenfrom The resultsindicategoodagreementwiththehypothesisthat,initially,anevolving 1116 CHARLESRAYTOLBERT it mightbeassumedthattheseareopticalsystems.However,0,Tauknown star movesupwardandtotherightofmainsequence(JohnsonHiltner1956) hypothesis, buttherearetwodeviations.For0,TauandADS14720,bothwith rate thandothesecondaries.ThefactthatmostofclassVprimarieslieabove class IIIsecondaries,itappearsthatthesecondaryhasevolvedmorerapidlythan in Figure6,AandB.Hereagain,mostofthesystemsagreewellwithevolution fall justbelowthecutoff,andcouldbe,therefore,extremelyoldsystems. has asecondarywhichisanAOpstarandwhoseplacementonthemainsequenceis, primary ofADS10635maybeaclassVobject(seenotestoTable3),and3910 itself withthepossibleexceptionsoffollowing:ADS15147andBDS1731Mv few primarieswhichfallbelowthecurvearewellwithinscatterofmainsequence can wellbetakenasevidenceofthemorerapidevolutionhotterstars.Those main sequenceandthatclassIIIprimariesexistinsystemswithmain-sequenceobjects and thattheprimaries,beingmoreluminousmassive,evolveatagreater primaries andlate-typesecondaries.AllthelieaboveNGC188boundary panions, andsystemslikeADS1490916633beingratheroldwithgiant maries arestillnearthemainsequencewhilebeingmuchbrighterthantheircom- therefore, doubtful.ItappearslikelythatthediscrepanciesofBDS1731andADS about 1.7;ADS10635whoseclassIVprimaryisatM=0.7;and3910 the componentsareplottedonmainsequencegivenbyBurbidgeand 15147 havebeenexaggeratedsomewhatbyusingstraight-linesegments,since,when (Sandage 1962)withtheexceptionsofADS10786,14345,and16633,which 1955), withsystemslikeADS513and7654beingquiteyoungsincetheirpri- (1958), theapparenterrorisgreatlyreduced. — 1.2.Thediscrepanciesofthesesystemscanprobablybeexplained,however. v © American Astronomical Society •Provided bytheNASA Astrophysics DataSystem Before beginningthisdiscussion, itshouldbestressedthatalltheanalysis tofollow The resultsofearlierstudiessuchasthoseStephenson (1960)andBidelman(1958) The systemswithsecondarieshavingluminositiesbrighterthanclassVareindicated Figure 5istheH-Rdiagramforsixty-eightsystemswithclassVsecondaries. It seemsevidentthatbinariescoverawiderangeofages(seealsoStruveandFranklin VII. ESTIMATEDPHYSICALPARAMETERS 19 64ApJ. . .139.1105T © American Astronomical Society Provided bytheNASA Astrophysics DataSystem

Fig. 5.—H-R diagram for systems with class V secondaries. All secondaries were placed on the 19 64ApJ. . .139.1105T strong correlationisseentobesolelythereflection oftheselectioneffectsinherentin data tothemuchnarrowerregionindicatedin figure.Therefore,thisapparently separations, theselimitscorrespondingtothecut-off linesinFigure7.Thepresent the study.Figure8,whichinvolvesdifferentialmagnitudes, isfreefromtheseselection data, however,fellwellwithintheseboundsso that theactualcut-offsrestrict magnitude oftheprimary,butitcanbeshownthat thisisduetoselectioneffects.At spective sequences. located ontheclassIVsequence;B,systemswithtypeA orclassIIIsecondaries,locatedontheirre- effects andexhibitsnocorrelations. the mass-luminosityrelation. Ontheotherhand,itwaspossibletoproceed theother the beginningofstudydefinitelimitswereplaced ontheapparentbrightnessand Figure 7showsanapparentcorrelationoftheintrinsic separationwiththeabsolute units (Table4).Thisseparationis,ofcourse,onlytheprojectiononplane as close2.5pctodistant2,200pc,withtheaveragebeingabout150pc. sky ofthetrueseparation,and,assuch,shouldbeconsideredaminimumvalue. it waspossibletodeterminetheintrinsicseparationofeachsysteminastronomical of theeighty-sevensystemswhichwereconsideredtobephysical.Theyrangefrom in ,arelistedTable4,alongwiththeabsolutemagnitudesofcomponents m 1118 CHARLESRAYTOLBERT © American Astronomical Society •Provided bytheNASA Astrophysics DataSystem Since orbitaldatawerenot availableforthesesystems,itwasimpossibleto improve By usingthesedistancesandtheapparentseparationstakenfromAitken(1934), Fig. 6.—H-Rdiagramforsystemswithnon-classVsecondariesA,classIVsecondaries, 19 64ApJ. . .139.1105T BDS 1731 ADS ADS 3962 BDS 2313 ADS 3085 ADS 2157 ADS A. ClassVSecondaries HR 5114 ADS 4134 ADS 3910 ADS 3317 ADS 3179 ADS ADS ADS HR 5531 ADS 9258 ADS 4262 ADS 4188 ADS 4182 ADS 4000 ADS 6783 ADS 5103 ADS 4749 ADS 9626 ADS 9559 ADS 9277 BDS 6498 ADS 10129 ADS 9951 ADS 8695 ADS 8530 ADS 8347 BDS 5652 ADS 7967 ADS 7654 ADS 7438 ADS 7311 ADS 6988 ADS 6913 ADS 8162 System © American Astronomical Society •Provided bytheNASA Astrophysics DataSystem 1982 1563 899 513 903 2 r 7\ Per. HD 21700 HD 118266 HR HR HR a HR HR e HR 23 88 62 77 a HR HR 5397 HR -J 30 Tt HR a HR HD 73668 HD 70516 6 6 27 35 65 83 -0 t*- 12 ~r 17 X i Name Tau. Ari. Psc. Psc. And. Ari. Boo. Ori. Tau. Tau. Boo. Lib. Ori. Ori. U.Ma. U.Ma. Cnc. Gem. Dra. Com. Com. Hya. 2174 1753 1322 4249 Leo 1945 1887 1779 Sco. 5415 5074 3811 Secondary - .58 -2.90 -2.34 -1.90 -1.02 -1.01 -3.65 -1.74 - .58 2.32 4.09 4.03 3.98 4.30 3.60 3.16 5.12 2.10 3.54 3.92 4.58 4.51 1.82 4.30 5.73 6.76 3.49 4.20 4.14 6.05 3.48 5.34 6.92 3.70 M .63 .52 .96 .62 .09 .09 .73 ■4.08 ■1.20 ■2.5 ■5.74 ■ .80 ■1.94 -1.03 -4.01 -1.21 - .72 -1.58 -3.21 -1.02 ■ .66 -4.87 ■3.18 -6.97 4.50 3.07 3.49 1.49 1.77 1.34 2.37 1.47 4.57 5.05 1.67 1.15 1.46 5.84 2.39 1.32 3.11 1.69 .73 .02 .15 .44 .23 .51 Primary Luminosity TABLE 4 III-IV Class (III)' 1119 III III III III III III IV IV IV IV IV II IV IV II (V)' (V)- V V V V* V V V Am V V V V V V V V lb V V V V V Distance () 158 603 316 575 182 100 144 263 780 501 631 263 263 209 263 100 158 110 132 182 46 23 40 42 83 50 66 46 24 21 76 76 76 35 33 76 40 26 50 52 13 Projected Separation (A.U.) 16,000 41.000 33.000 19.000 12,000 30.000 18.000 14,000 11,000 15.000 11.000 11.000 4.700 6,600 2,600 4.200 2.900 6,300 1,600 1,500 6,000 3.500 1.500 2.600 4,800 4,900 6.800 3.800 1,600 6,100 6,800 3.600 2.200 4.900 2.700 4,100 4.600 1.900 910 990 380 Mass^ Total 10.4 26.6 31.9 18.3 10.4 10.0 19.3 17.2 12.2 8.3 8.0 4.0 2.4 2.6 4.2 5.1 3.6 3.2 6.2 3.4 3.2 4.0 3.7 7.4 7.8 1.9 8.8 2.7 2.7 7.1 3.6 5.7 3.7 5.4 3.2 5.3 2.9 3.6 1.8 1.6 1.4 3 (l0Years) Period 1,600 1,100 1,500 1,900 230 410 250 250 610 630 190 280 200 550 110 560 170 180 110 480 790 180 130 180 6.2 140 82 42 41 36 74 84 36 97 81 54 78 49 20 25 98 19 64ApJ. . .139.1105T HR ADS ADS HR ADS 6588 BD+31.1676 B. ClassIVSecondaries ADS 11639 ADS 6028 ADS ADS ADS ADS ADS ADS ADS ADS ADS ADS ADS ADS 3579 HR 1165 ADS ADS ADS ADS ADS ADS ADS ADS ADS ADS ADS ADS ADS HR ADS ADS System © American Astronomical Society •Provided bytheNASA Astrophysics DataSystem 14345 16481 15764 15147 14909 14636 13870 13554 16611 10149 16633 15434 14101 13379 13087 12815 10535 12913 12767 12750 10786 10759 10635 11593 11336 10966 8470 3590 6575 9474 7300 n HD 132910 HD 77250 HD 160315 HD 106365 HR 3174 HD 63610 HD 57044 HR HD 208392 HD 219175 HR 8777 HR 8493 HD 198624 HR HD 190850 91 Aqr. 61 Cyg. 31 Cyg. HD 180262 HR HR 57 HR 7475 54 37 53 17 39 67 16 Y h K S Lyr. 3 Peg. 1 Peg. Name Tau. Del. 7827 Aql. Her. 1600 Cyg. Cyg- Dra. Oph. Oph. Sgr, Her. Dra. 7033 6491 Secondary - .37 - .95 -5.18 -1.03 -1.30 -1.90 -1.90 - .58 -1.16 10.60 2.50 2.10 3.05 2.10 2.15 2.15 7.08 4.47 5.07 2.10 3.32 5.94 6.32 7.09 9.03 1.94 4.03 4.03 4.25 2.71 3.81 1.50 5.08 1.94 1.16 M .40 .25 -4.53 -2.67 -4.97 - .93 -2.18 -5.32 ■2.65 • .49 ■1.25 -3.80 -3.81 - .29 -6.08 - .09 8.21 1.78 1.64 2.87 TABLE 4-Continued 1.03 1.16 1.05 2.13 4.44 4.82 1.84 1.05 3.53 3.05 4.26 1.13 1.19 M Luminosity .76 .68 .83 .78 .71 .12 Primary II- II- 1120 Class III III III III III III III III III III* III III IV IV II* IV IV IV IV II IV IV IV V V V V V V V V* V V* V lab lb Distance (Parsec) 2,230 2.51 597 457 110 126 138 100 200 302 398 940 191 144 144 6.9 295 501 603 174 100 138 980 191 100 216 52 42 28 26 76 44 17 60 20 58 19 Projected Separation 140,000 27.000 12.000 49.000 19.000 32.000 15.000 23.000 14.000 33.000 27.000 13.000 17.000 25.000 (A.U.) 12.000 5,200 2,300 3,700 7.000 5,500 3.000 6.000 5,200 4,100 1.000 9,400 5,700 1,300 1,600 2,800 5,200 4,400 490 650 230 620 63 Total Mass 35.0 14.1 10.5 15.0 14.9 20.9 11.0 16.4 A 9.2 6.1 4.3 4.1 4.0 3.8 3.7 4.3 6.8 4.9 4.7 2.6 5.2 3.5 3.5 5.3 4.2 4.8 2.0 1.0 9.7 2.5 4.3 3.6 6.4 3.6 1.9 1.9 1.3 3 (10Years) 2,100 Period 2.900 1,400 8.900 1,200 1,500 1,500 200 650 860 7.1 0.5 830 420 110 430 150 500 180 160 7.9 210 270 9.2 160 870 450 970 200 3.0 9.8 130 53 88 34 12 78 19 64ApJ. . .139.1105T ADS 8001 HR 1412 ADS 14720 ADS 8883 BDS 1094 ADS 8568 ADS 10628 BDS 9705 D, ClasslbSecondaries C. ClassIIISecondaries E. TypeAmSecondaries ADS 1073 ADS 6913 ADS 1073 ADS 3910 ADS 12913.x ADS 8530 ADS 8162 ADS 8001 ADS 13554 ADS 11336> ADS 10535'N © American Astronomical Society •Provided bytheNASA Astrophysics DataSystem System HD 95098 0 Tau. HD 116442 HR 8107 HD HD 188212 17 Both componentsassumedClassIIIfromcolor-colordiagram. Both componentsassumedClassVfromcolor-colordiagram. Absolute magnitudeofsecondartakenfromArp's(1958)calibration. Secondary isAOp,butassumedonmainsequence. Primary composite-listedasK2II+B3VbyBidelman(1954). Primary assumedClassIII. See ADS6913. Secondary assumedClassV. Name 12927 Cbm. Dra. Cas, Secondary (-5.6) 2.70 2.60 2.87 1.90 ,30 ,55 ,45 M 15 (-7.5) •1.68 1.14 TABLE 4-Continued 2.00 2.56 2.68 .01 .25 .55 Primary Luminosity Class (III) III III III AOp V 1121 la' Distance (Parsec) 1,620 229 575 330 46 79 87 78 29 Separation Projected 220,000 45,000 20,000 16,000 12,000 (A.U.) 6,200 4,400 3,300 1,800 Mass© Total 29.6 8.2 8.1 5.4 5.9 4.9 3.4 3.2 3.1 3 (10Years) 1,100 Period 1,900 840 210 990 590 160 110 43 19 64ApJ. . .139.1105T responds toconditionsof10thmagnitudeand300"separation. responds toconditionsofOthapparentmagnitudeand25"separation.Thelowercutoffcor- © American Astronomical Society •Provided bytheNASA Astrophysics DataSystem Fig. 7.—Absolutemagnitudeoftheprimaryversusintrinsicseparation.Theuppercutoffcor- o i e 9 9 OCLASSIX 6 4 •TYPEAp ,50 ,100 AMy ■ CLASSI A CLASSX PRIMARIES a TYPEA A CLASSm • CLASS7 M Fig. 8.—Differentialmagnitudeversusintrinsicseparation (Astrohom.cal Urits, SEPARATION 0 00 1122 19 64ApJ. . .139.1105T conditions of0thapparentmagnitudeand25"separation.Thelowercutoffcorrespondsto widely separatedsystemslendsweighttothediscussion of“proper-motionpairs”as generous outerlimits.Againthegeneraltrendof pointscanbeexplainedbyselection lines wereestablishedbytransferringthecut-off lines fromFigure7withtheassump- cussion). SincetheaverageEb-vwasusedfor the system,absolutemagnitudes conditions of10thmagnitudeand300"separation. without beingtornapart bythestochasticandshearforcesofgalaxy. According being physicalbinariesofgreatseparation(vanBiesbroeck 1957;vandeKamp1961). effects, buttheapproximatelimitofabout40000 a.u. seemsreal.Theexistenceofsuch tion thattheprimarywashalfasmassive wholesystem.Theyare,therefore, and hencethemassesforcomponentsappear large. system, eventhoughitexhibitsalargereddening discrepancy(seethereddeningdis- question ariseswhethersuch systemsarephysical,andiftheycouldexist for verylong should bepointedoutthatADS15434hasbeentreatedasthoughitwereaphysical to Huang(1957),abinary systemwouldnotbestableforseparationsgreater thanabout and, moreovertherelativeradialvelocitybetweenmostofcomponentsislessthan orbital motionformostofthesesystemsisoutthequestionmanyyearstocome, since theydependontheprojectedseparations;andrangefrom500yearsfor ADS 14636toabout9000000yearsfor15434.Itisclearthatobservationof involve somewhatmoreerrorthandothemassesofmain-sequenceobjects.The derived massesandperiodsarelistedinTable4.Theminimumvaluesonly, regard toluminosityclass,itisprobablethatthemassesofgiantsandsupergiants periods forthesystems.Sincesamemass-luminosityrelationwasusedwithout and thebolometriccorrectionsofPopper(1959),toobtainmassesprovisional 1 km/sec,sothatconfirmationfromradialvelocityobservationsisalsounlikely.It way and,byusingtheempiricalmass-luminosityrelationasquotedStrand(1957Ó) © American Astronomical Society •Provided bytheNASA Astrophysics DataSystem The twosystemswhichexceed40000a.u.areADS 1073andADS15434,the Figure 9isaplotoftheseparationsversus sum ofthemasses.Theboundary Fig. 9.—Totalmassofthesystemversusintrinsicseparation.Theuppercutoffcorrespondsto WIDE VISUALBINARIES1123 1124 CHARLES RAY TOLBERT Vol. 139

one-half of a mean interstellar distance, which would imply stable systems with sepa- rations as great as about 1.5 pc (for a mean interstellar distance of 3 pc as given by Chandrasekhar 1942). Both of the systems in question fall within this range of stability, and, moreover, both have extremely massive components, i.e., around 15 Mq, and would be able to withstand greater disruptive forces. It is very possible, therefore, that these could indeed be physical systems. Both components of ADS 1073 (0 Cas) are luminosity class I objects and have been studied as possible members of NGC 457 by Pesch (1959). The components of ADS 15434 are both early B-type main-sequence stars. VIII. CONCLUSIONS After observing photoelectrically ninety-four visual binaries with separations greater than 25", the following was found: 1. Systems with separations of about \5" probably could be observed with adequate care using the 24-inch telescope, but systems of smaller separations would require modifications of the observing techniques. 2. Unambiguous reddening determinations were made for all but five of the systems. 3. Seven of the systems were found to be optical. 4. Good confirmation was found for the theories of common origin and evolution. Each component apparently evolved as a single star without close-binary-type inter- actions. 5. The distances for the systems ranged from 2.5 to 2200 pc. 6. A projected intrinsic separation was determined for each of the systems. They ranged between 63 a.u. and 220000 a.u. 7. The sum of the masses was estimated for each system. The range was from 1 to 35 Mq. 8. A provisional period was obtained for each system, ranging from 500 to 9000000 . 9. No correlations were found between separation and magnitude, except those introduced by selection effects. 10. An upper limit of about 40000 a.u. was found for the intrinsic separations of these systems. 11. Two systems were found with exceptionally large separations: 140000 a.u. and 220000 a.u.

The author would like to thank Drs. Robert Hardie and Arnold Heiser for their guidance and advice. Thanks are also due to Dr. William Bidelman for his useful dis- cussion and comments on the problem, and to Dr. Arne Slettebak for kindly providing his spectral data prior to publication. The support of the Natural Science Committee of Vanderbilt University, the Research Corporation, and the National Science Foun- dation in several phases of this investigation is also greatly appreciated.

REFERENCES Aitken, R. C. 1934, of Double Stars (Washington, D.C. : Carnegie Institution of Washington). Arp, H. C. 1958, Handbuch der Physik (Berlin: Springer-Verlag), 51, 75. Berger, J. 1962, Ann. d’ap., 25, 1. Bidelman, W. P. 1954, Ap. J. Suppl., 1, 175. 1958, Pub. A.S.P., 70, 168. Biesbroeck, G. van. 1957, R.A.S.C., 51, 29. Burbidge, G. R., and Burbidge, E. M. 1958, Handbuch der Physik (Berlin, Springer-Verlag), 51, 134. Chandrasekhar, S. 1942, Principles of (Chicago: University of Chicago Press), p. 248. Eggen, O. J. 1963, A.J., 68, 483. Hardie, R. H. 1962, Stars and Stellar Systems (Chicago, University of Chicago Press), 2, 178. Huang, Su-shu. 1957, J.R.A.S. Canada, 51, 40.

© American Astronomical Society • Provided by the NASA Astrophysics Data System No. 4, 1964 WIDE VISUAL BINARIES 1125 Jaschek, C., and Jaschek, M. 1959, Zs.f. Ap., 47, 29. Johnson, H. L. 1953, Ap. 117, 361. Johnson, H. L., and Hiltner, W. A. 1956, Ap. 123, 267. Johnson, H. L., and Knuckles, C. F. 1955, Ap. /., 122, 209. Johnson, H. L., and Morgan, W. W. 1953, Ap. 117, 313. Kamp, P. van de. 1961, Pub. A.S.P., 73, 389. Pesch, P. 1959, Ap. /., 130, 764. Popper, D. M. 1959, Ap. /., 129, 647. Sandage, A. 1962, Ap. /., 135, 133. Slettebak, A. 1963, Ap. /., 138, 118. Stephenson, C. B. 1960, A./., 65, 60. Strand, K. Aa. 1957a, A.J., 62, 35. . 19576, J.R.A.S. Canada, 51, 46. Struve, O., and Franklin, K. L. 1955, Ap. 121, 337. Wallenquist, A. 1958, Ark. Ast., 2,171.

© American Astronomical Society • Provided by the NASA Astrophysics Data System