1995AJ 110.2926H THE ASTRONOMICALJOURNAL time, theprecisionofphotometricobservationsmadewith new observingtactics,andrigorousquality-controlmonitor- the submillimagnituderegimearebeinginitiated(Henry through theuseoflargerapertures,precisionphotometers, ductive, andmoreeconomical(Henry1995a).Atthesame tronomy Observatories,operatedbythe AssociationofUniversitiesforRe- this paperwepresenttheresultsofanewsurveyknown ing (Henry1995b).Observationswithmillimagnitudepreci- scopes havebecomeincreasinglymoreefficient,pro- dation. telescope (APT),whichtakes advantage ofmanythese Vanderbilt/Tennessee State0.4 mautomaticphotoelectric and likelychromosphericallyactivestarsconductedwiththe scheduling andmanagementofrobotictelescopeseasier such telescopeshasimprovedbyanorderofmagnitude search inAstronomy,Inc.,undercontract withtheNationalScienceFoun- scientifically moreproductive(Drummondetal.1995).In sion arenowroutineonlargertelescopesandventuresinto 2926 Astron.J.110 (6),December1995 0004-6256/95/110(6)/2926/42/$0.90 ©1995Am.Astron. Soc.2926 Visiting Astronomer,KittPeakNational Observatory,NationalOpticalAs- 1995b). Sophisticatednewsoftwaretoolsaremakingthe Over thepastseveralyears,operationswithrobotictele- © American Astronomical Society • Provided by the NASA Astrophysics Data System Center forAutomatedSpaceScienceandofExcellenceinInformationSystems,TennesseeStateUniversity,330TenthAvenue We havecompletedanautomatedphotometricsurveyof66potentialorknownchromosphericallyactive 47 stars,41ofwhicharenewlydiscoveredvariables.Theprimarymechanismvariabilityisrotational represents asignificantimprovementintheprecisionofpreviousrobotictelescopesurveys late-type starswiththe0.4mVanderbilt/TennesseeStaterobotictelescope.Theprecisionof been determinedbycomparisonwithstarsofknownabundances.Inmostcasesourabundancesaremuch unidentified. High-dispersionspectroscopicobservationsofallthevariablestarsalsohavebeenobtained variability mechanismofHD99267,anewlyidentifiedmembersmallgroupearly-Fstars,issofar modulation ofaspottedsurface.InadditionwehavedetectedeclipsesinHD62668and141690 and analyzedtodeterminespectraltype,vsin/,velocityvariabilityforeachstar.Asaby-productofthe the ellipticityeffectinHD223971.Thelightvariationsof181475areresultpulsationwhile chromospherically activestars.Lightvariabilityhasbeendetectedanditsperioddeterminedfor observations fromthistelescopematchesthatpredictedphotonandscintillationnoisealone binary systemissynchronouslyrotating.Importantquestionsremainabouttheevolutionarystateor closer tothesolarvaluethanthosepreviouslymeasured.TheminimumradiusandRossbynumberofeach spectral-type determinations,approximateabundancesforanumberofsupposedmetal-poorbinarieshave duplicity ofsomeourstars,includingHD17925,22694,29697,51066,72146, 98800, BD+13°13,+70°959.CandidatesforDopplerimagingincludeHD51066,82286, spotted starhavebeencomputed.Wealsodeterminedwhetherornotthecomponentofeach 171488, andHD208472.©7995AmericanAstronomicalSociety. AN AUTOMATEDSEARCHFORVARIABILITYINCHROMOSPHERICALLYACTIVESTARS 1. INTRODUCTION Dyer Observatory,VanderbiltUniversity,Nashville,Tennessee37235 Electronic mail:[email protected],[email protected] 1 Gregory W.HenryandFrancisC.Fekel Received 1995August9;revisedSeptember5 Electronic mail:[email protected] North, Nashville,Tennessee37203-3401 VOLUME 110,NUMBER6 Douglas S.Hall ABSTRACT previous robotic-telescopesurveysofchromosphericallyac- tive stars.Almosttwo-thirdsofthissamplenewvariable II) byStrassmeieretal.(1993).Thefirsteditionofthiscata- photometry aswellhigh-dispersionspectroscopyforeach known CallHandKemission,late-typebinaries,young we take,asourprimarysourcesofcandidates,starswith low-amplitude variablestarsarefoundinthissurveythan advances inautomatictelescopes.Asaresult,manymore ultraviolet sources.Inthispaperwereporttheresultsofour stars haveamplitudes^0.05mag. both CCABSIIandFekel&Balachandran (1994).Infuture present work.Resultsinthispaper supersedethosegivenin of the47variablestars.Preliminaryresultsforsomeour log (Strassmeieretal.1988)willbereferencedasCCABSI. or inthecandidatelist(Table7)ofsecondeditionA single stars,andopticalcounterpartstox-rayextreme editions ofCCABSsomethe candidatescanbeadvanced extensively discussedandsometimes slightlyrevisedinthe stars alreadyhaveappearedinthemaintables(Tables1-6) Our spectroscopicresultsfora few ofthestarswerebriefly summarized byFekel&Balachandran (1994)butaremore Catalog ofChromosphericallyActiveBinaryStars(CCABS 1988b), Strassmeieretal.(1989),andHooten&Hall(1990) Following theworkofStrassmeier&Hall(1988a, DECEMBER 1995 1995AJ 110.2926H 2927 HENRYETAL.:CHROMOSPHERICALLYACTIVESTARS papers thatusedunfamiliarnames, suchassatellite-catalog to themaintableswhileafewshouldbedeletedbecause designations, forrelativelybright stars.Insomepapersthe they haveproventobesinglestars. At timesduringourextensiveliterature searchwefound © American Astronomical Society • Provided by the NASA Astrophysics Data System 6 2. LITERATURESEARCH û 29697 +20°802 22694 +17°601 7205 +40°248 39743 +49°1423 62668 +47°1484 51066 +75280 33363 +75°217 18632 +7°459 17925 -13°544 85091 +11°2108 82286 +63°848 80953 +64°733 72429 +11°1865 72146 +29°1772 70573 +2°1951 18645 -1®428 98800 (-24°9706) 89546 +61°1183 82443 +27°1775 HD(HDE) BD(CD)OtherHRIRASHÏC 99267 +30°2154 112859 -j-47°2007 118981 -f2°2705 118234 +21°2548 113816 -4°3419 203387 -176245 202951 -f10°4516 144110 -f51°2051 131511 -h19°2881 122767 +25°2723 208472 -f43°4087 206301 “14°6102 148405 +24°3008 148127 +24°3003 141690 -f25°2973 223971 +38°5091 160934 181475 -4°4781 171488 -fl8°3734 (337518) +27°3245 +48°3686 +36°2193 +30°2130 -f70°959 -0°4234 +13°13 1E2349.8-0112 - SAO 130230 SAO 110894 SAO 116694 SAO 179815 SAO 120060 SAO 139157 SAO 143296 SAO 103862 SAO 1070208149 SAO 37026 SAO 93538 SAO 97905 SAO 80232 SAO 407202054 SAO 98794 SAO 14919 SAO 148753722 SAO 51891 SAO 44410 SAO 62550 SAO 15153 SAO 80897 SAO 84381 SAO 29761 SAO 84018 SAO 83143 SAO 82886 SAO 84364 SAO 51437 NSV 13768 SAO 73597 SAO 86811 SAO 91772 NSV 3726 SAO 6053 SAO 5481 V834 Tau NSV 68475553 Wa Tau1 32 ¿Cap8167 EX Dra Table 1.Staridentifications. EP Eri857 42 Cap8283 names, HRnumbers,Flamsteed numbers,and/orBayerdes- have compiledalistofnames for eachofthe47variables ignations, weuseHDnumberfollowed byBDnumberasthe To alleviatesuchidentification difficulties inthefuture,we came uponimportantresultsby chance ratherthanbydesign. all. Asaresult,despitetheuseofSIMBAD,wesometimes stars werepoorlycrossreferencedornotat (Table 1).Althoughafewof the starshavevariablestar 01102+4123 5684 02501-1258 13402 05532+4901 28162 04383+2048 21818 08292+2929 41875 07436+4727 38003 06575+7529 34101 05116+7553 24760 09299+6302 46919 09217+6409 46247 09298+2712 46843 11195-2430 10183+6109 50752 13327+2102 66286 21194-1702 105515 21532+4410 108198 21388-1416 107095 21164+1059 105224 16230+2410 80435 14009+2450 68660 14511+1921 72848 19181-0435 95099 41951 48215 55766 17076 13968 13976 66708 63958 63368 91043 86346 78519 55135 93817 56132 999 2927 1995AJ 110.2926H primary identifierintherestofthispaper.Twostarsareso possible andthree-nightrunningaveragesotherwise.Group program starwasobserveddifferentiallywithrespecttoa means ofmultiplemeasuresdeterminedbythetechnique not included.Valuescertaintobeonthe,UBVsystemare represent meansorcompositesofotherpublishedvaluesare logs maybeparticularlyusefulforfutureworkonthestars, of theaboveidentificationsarelistedbyotherdesignations. Bayer designation,Flamsteednumber,suspectedvariable umn 3variousothernamesincludingvariablestarname, number whilecolumn2liststheBDorCDnumber.Incol- identified byotherdesignations.Column1istheHDorHDE faint thattheyhaveneitheranHDnorBDnumberandsoare 2928 HENRYETAL:CHROMOSPHERICALLYACTIVESTARS noise aloneforthistelescopeand representsathreefoldor matches theprecisionpredicted from photonandscintillation magnitude, wasdeterminedto be around0.003magfrom term meantransformationcoefficients.Theexternalpreci- were transformedtotheJohnsonUBVsystemwithlong- mean differentialmagnitudesinthesenseV—CandK—C K,S,C,V,C,V>C,V,C,Swhere Kisthecheckstar,C per. range ofVmagnitudes,aswewillshow,ismarginallyuseful etry andtheknownVmagnitudesofcomparisonand/or magnitudes determinedfromourowndifferentialphotom- on theUBVsystemhasbeenpublished,wehavelistedV differential photometry.Infivecaseswherenophotometry all-sky photometrybutafew,appropriatelyidentified,are omitted aswell.Mostweredeterminedbythetechniqueof and TheHipparcosInputCataloguenumber(Turónetal. are listedincolumn4.Identificationsfromtwoothercata- Seven starsarebrightenoughtohaveHRnumbers,which star numberorSAOarelisted.Twostarswithoutany fourfold improvementintheprecision ofrobotictelescope observations ofselectedpairs especiallystablestars.This a singlenightlygroupobservation fromtheseasonalmean cients determinedfromstandard-starobservationswhenever vation. Inourreductionsweusednightlyextinctioncoeffi- the comparison,Visprogramstar,and5askyobser- included inthestandardgroupobservingsequence comparison starinbothBandVfilters.Acheckwasalso matic photoelectrictelescopeonMt.Hopkins,Arizona.Each ent visualmagnitude,givenintheBDCatalog,SAO literature valuesforit,itscomparison,orcheckstar.In- check stars.Inasixthcase,BD+48°3686,wefoundno so incolumns5and6wehavelistedtheIRASdesignation sion ofourobservations,definedasthestandarddeviation obtained withtheVanderbilt/TennesseeState0.4mauto- in corroboratingthevariabilitythatweestablishthispa- verifying thespectralclassand/orluminosityclass.The Catalog, andsimbad,whichshowarangeof0.8mag!The stead, thereareonlythreeverydisparatevaluesoftheappar- U—B thatwecouldfindintheliterature.Catalogentries 1992), respectively. U-B andB—Vindicesprovehelpful,insomecases, © American Astronomical Society • Provided by the NASA Astrophysics Data System Table 2listsindependentdeterminationsofV,B—and Photometric observationsofthestarsinoursamplewere 3. PHOTOMETRICOBSERVATIONSANDANALYSES brightness variationsaretheresultofrotationalmodulation periodogram analysisforeachstar,derivedfromthedatain When interestingcomparisonscouldbemadewithothersub- parison andcheckstarshaveproven tobevariableaswell bined withthestar’svsin/,givesaminimumradiusconsis- plitude atthatperiodmustbestatisticallysignificant.(2)The from inspectionofthelightcurve.Thevastmajority the Julian-daterangelisted,aregivenincolumn6.Column7 results inourdiscussionoftheindividualstars.The This subsetisspecifiedforeachstarincolumns4and5. photometry (Henry1995b).Detailsaboutthetelescope,pre- better oddsfordetectionofvariability thanthemore-or-less meet ourcriteriaforinclusionas adefinitenewvariable.Our tion tothe42variableprogramstars,five(4%)ofourcom- ing variability.Forsixofthe42stars,priorannouncements tent withthestar’sspectraltype. riod expectedincasesofaclosebinarysystemcontaining than oneobservingseasonor,ifthevariabilitywasseenin parison andcheckstars. stars inoursamplearechromosphericallyactive,sotheir gives theamplitudeoflightvariability,usuallydetermined chosen todemonstratethevariabilitymostconvincingly. two tofiveseasonswiththeAPT,wehavegenerallypre- tively. Althoughmostofthestarshavebeenmonitoredfor list thevariablestar,comparisonandcheckrespec- each starunlessotherwisespecified.Thefirstthreecolumns in Table3,weredeterminedfromtheVbandobservationsof also canbefoundinHenry(1995b). ments intheprecisionofautomatic-telescopeobservations cision photometer,reductionmethods,andfurtherimprove- random selectionofcomparison andcheckstarsfromthe criteria forpotentialnewvariables obviouslyresultinmuch and areincludedinthispaper. A sixth,HD113449,didnot of variabilityhaveoccurredintherecentliterature.Inaddi- able inthispaperandacouplemore,notincludedhere,are one spottedstarortheobservedphotometricperiod,com- is veryclosetothesynchronousorpseudosynchronouspe- Plausibility inthiscontextmeansthatthephotometricperiod only oneobservingseason,theperiodshouldbeplausible. data sets.(3)Thesameperiodicitymustbepresentinmore as follows:(1)Thevariabilitymustbeperiodicandtheam- we candemonstrateconvincingvariability.Ourcriteriawere observations aswellacheckontheconstancyofcom- means. Thisservesasameasurementoftheprecision comparison-star observationsfromtheirrespectiveseasonal within thatrange.ThefinalcolumnofTable3givesthe given incolumn4,7citesthelargestamplitude 7. IftheamplitudeisvariablewithinJulian-daterange eclipses buttheeclipsevariationsarenotincludedincolumn Several starsexhibitadditionallightvariationsdueto of starspots.Theremainingstarsvarybyothermechanisms. sets ortheentiredataset,wehavepresentedadditional sented theanalysisofonlyonesubsetobservations, suspected variablesthatdidnotmeetourcriteriaforconvinc- same periodicitymustmanifestitselfinboththeVandB standard deviationofthenightlycheck-starminus The resultsofourphotometricobservations,summarized Of the66starsinoursurvey,42(64%)arereportedvari- This paperincludesonlystarsfromoursurveyforwhich 2928 1995AJ 110.2926H 2929 © American Astronomical Society • Provided by the NASA Astrophysics Data System HENRY ETAL.\CHROMOSPHERICALLYACTIVESTARS HD 82286 HD 80953 HD 62668 HD 72429 HD 72146 HD 70573 HD 18632 HD 51066 HD 39743 HD 33363 HD 29697 HD 22694 HD 18645 HD 17925 HD 7205 Star (mag) 8.351 8.692 8.739 6.041 7.280 7.703 7.707 8.004 6.075 6.023 6.071 6.026 6.23 7.939 7.946 6.956 6.062 6.057 6.27 6.28 7.996 7.954 7.961 7.549 8.247 6.01 6.06 6.00 6.47 8.01 7.932 7.254 8.00 8.01 6.06* 6.04 6.05 6.04 6.05 6.08 6.04 6.05 6.04 6.01 6.04 8.01 8.28 6.05 8.25* 8.01* 7.98 8.19 7.27 V Table 2.PublishedUBVmagnitudes. B-V (mag) 0.876 0.994 0.87 1.290 0.87 1.48 1.47 0.83 0.81 0.88* 0.85 0.86 0.86 0.87 0.87 0.86 1.46 1.08 1.095* 0.87 0.88 0.87 0.87 0.77 1.09 1.11 1.08 1.06* U-B. (mag) 0.565 0.55 0.92 0.985* 0.945* 0.56 0.31 1.74 0.94 0.60* 0.58 0.54 0.56 0.55 1.74 0.91 0.93 0.38 0.40 M Rybka (1979) Rybka (1969) this paper*** this paper Johnson etal.(1966,Table2) Olsen (1993) Elvius &Haggkvist(1966) Johnson etal(1968) Johnson etal.(1966,Table10) Upgren &Lu(1986) Bessel (1990) Petit (1990) Petit (1990) Rufener (1988) Blanco etal(1979) Eggen (1978) Feinstein (1966) Lake (1964) Nikonov etal.(1957) Johnson &Knuckles(1957) Olsen (1994) Olsen (1994) Olsen (1993) Eggen (1974) Rufener (1988) Olsen (1983) Rufener (1981) Rufener (1976) Sandage &Kowal(1986) Olsen (1983) Olsen (1993) Olsen (1993) Haggkvist Oja(1987) Rufener (1988) Sandage &Kowal(1986) Epps (1972) Olsen (1993) Cutispoto (1992) Golay (1973) Rufener (1971) Sandage &Smith(1963) Cousins &Stoy(1963) Olsen (1993) Chugainov (1981) Chugainov (1981) Latham etal(1992) Olsen (1983) Scharlach &:Graine(1980) Olsen (1993) Cousins etal(1966) Olsen (1993) Sandage (1969) Olsen (1993) Oja(1987b) Reference 2929 1995AJ 110.2926H 2930 © American Astronomical Society • Provided by the NASA Astrophysics Data System HENRY ETAL:CHROMOSPHERICALLYACTIVESTARS HD 82443 HD 112859 HD 98800 HD 89546 HD 85091 HD 118981 HD 118234 HD 113816 HD 99267 HD 131511 HD 122767 HD 160934 HD 148405 HD 148127 HD 144110 HD 141690 HD 171488 HD 203387 HD 202951 HD 181475 Star (mag) !<, V 6.880 Olsen(1983) 7.597 Rufener(1981) 7.020 Rufener(1988) 7.030 Rufener(1981) 7.032 Rufener(1976) 6.98 0.7760.347Sturch&Helfer(1972) 8.228 Olsen(1994) 8.200 Olsen(1993) 7.452 -thispaper'' 7.589 -Rufener(1988) 7.610 0.6100.05Carney&Latham(1987) 7.613 -Olsen(1983) 8.21 0.570.05CarneyfcLatham(1987) 8.21 0.570.01Sandage&Kowal(1986) 8.27 1.15---Buckleyeisí.(1987) 6.87 0.310.02Oja(1985) 8.945* Henry&Hall(1994) 9.13 -Zuckerman&Becklin(1993) 8.89 1.251.12Gregorio-Hetemetal.(1992) 9.08 1.261.07Eggen(1974) 7.64 0.600.01Sandage&Kowal(1986) 7.61 McMillanetal.(1976) 7.01 0.770.33Eggen(1964) 7.01 0.770.33Argue(1963) 6.019 -Rufener(1976) 6.017 Golay(1973) 7.96 1.331.43Haggkvist&Oja(1973) 7.57 1.080.93Haggkvist&Oja(1973) 7.98 0.930.54Schild(1973) 6.00 0.840.49Argue(1963) 6.01 0.83-Nikonovetal.(1957) 8.626 Olsen(1993) 8.666 Olsen(1993) 6.001 Olsen(1993) 6.016 -Rufener(1988) 5.994 Olsen(1983) 6.019 Rufener(1981) 6.00 0.840.49Eggen(1978) 4.274 Rufener (1981) 4.296 0.8900.630Celis (1975) 4.267 0.9160.551Johnson etal.(1966,Table4) 4.269 0.8970.565Johnsonetal.(1966,Table4) 4.290 0.9020.577Gutierrez-Morenoeial.(1966) 5.977 Rufener(1988) 6.006 Rufener(1981) 7.456 Olsen(1994) 7.389 Olsen(1983) 8.96 0.910.52Oja(1984) 8.69 0.620.14Guetter(1980) 8.66 0.650.19Eggen(1963) 6.04 -Jaseviciusetal.(1990) 6.01 Petit(1990) 5.97 0.840.57Kamper&Lyons(1981) 6.02 0.830.52Cowleyetal.(1967) 4.274 Rufener (1988) 4.27 0.910.56Johnsonetal.(1966,Table2) 4.28 0.900.57Cousins&Stoy(1963) 5.96 1.648-Haggkvist&Oja(1987) 6.96 2.072.14Fernie(1983) 6.91 Pel(1976) 10.28 1.230.95Weis(1993) 7.79 1.601.95Oja(1987a) 4.29 0.9030.58Haggkvist &Oja(1987) 4.28 0.870.59van den Bergh(1967) 4.29 0.900.57Johnson etal.(1966,Table10) B-V (mag) Table 2.(continued) U-B (mag) Reference 2930 1995AJ 110.2926H 98800, BD—0°4234,and+13°13). Ontheordinateare viously publishedsources(for HD 17925,29697, text) andsquaresareÀV(differential) amplitudesfrompre- are ÀV(differential)amplitudes fromourpaper(Table3or are amplitudesfromdifferential photometry,wherecircles differential photometry.Wedothis inFig.1.Ontheabscissa ing inTable2withtheamplitudeofvariabilitydiscoveredby cally activestars. & Hall(1990)intheirsurveyofsuspectedchromospheri- field. Asimilarsuccessrateof68%wasenjoyedbyHooten 2931 © American Astronomical Society • Provided by the NASA Astrophysics Data System It isinstructivetocomparetherangeofVvaluesappear- HENRY ETAL:CHROMOSPHERICALLYACTIVESTARS d 6 ,t VmagnitudefromRufener(1988) '"mean ofvar-checkdifferentialmagnitude mean ofvar-compdifferentialmagnitude "mean ofrangefromdifferentialphotometry Wa Tau1 VmagnitudefromNicolet(1978) BD +70*959 BD h»48°3686 BD +36°2193 BD +30°2130 BD +13°13 IE 2349.8-0112 BD -0°4234 HDE 337518 HD 223971 HD 208472 HD 206301 Star r rt :r 10.34 0.940.49Martineta/.(1994) 10.37 0.960.58Walter(1986) 10.66 thispaper’ 9.887 0.6690.112Figueraseta/.(1990) 9.820 Rufener(1988) 5.167 ---Olsen(1994) 5.152 -Olsen(1993) (mag) 9.870 Spiteetal(1984) 9.89 0.670.12CarneykLatham(1987) 9.29 0.620.15CarneykLatham(1987) 8.50 0.810.26Bergoffenetal(1988) 6.631 ---Olsen(1983) 9.70" 1.08"0.90"Jetsuetal(1992) 8.59 0.810.27SandagekKowal(1986) 8.59 0.810.27Sandage(1981) 9.78 0.940.50Upgrene*a/.(1992) 9.81 LazauskaitekTautvaisiene(1990) 8.44 0.78"0.28"Rodonoeta/.(1994) 9.90 0.970.50SandagekKowal(1986) 5.147 -Rufener(1988) 5.133 -Rufener(1976) 9.89 0.980.48Petersonetal(1980) 9.89 0.94Wanner(1972) 7.455 thispaper^ 5.136 -Rufener(1981) 5.164 0.6740.181Jennens&Heifer(1975) 9.90 0.970.49Sandage(1969) 9.89 0.960.48Eggen(1968) 9.89 0.960.48EggenkGreenstein(1965) 8.92 thispaper'’ 6.63 0.670.31Walker(1971) 5.18 Jaseviciuseia/.(1990) 5.13 KeenankYorka(1988) 5.17 -Regleroetal(1987) 5.15 0.6650.15Eggen(1978) 5.15 0.67---Corbin(1971) 5.18 0.650.20Eggen(1965) V B—V (mag) Table 2.(continued) U-B (mag) Notes toTable2 majority arelarger(abovetheline). Weunderstandthisby- line) becauseatypicalsingleentry inTable2isameanof majority oftheTable2ranges to besmaller(liebelowthe correlation, thoughnotatightone. Frankly,weexpectedthe not themuchlargereclipseamplitude.Thestraightlinein- the combinedellipticityeffectplusstarspotvariabilitybut several individualmeasuresat different epochs.Infact,the dicates perfectcorrelation,and weseethereisapositive value ofAV(differential)plottedrepresentstheamplitude the rangesofvaluesVinTable2.ForHD223971, Reference 2931 1995AJ 110.2926H played overseveralyearstobe larger thanamplitudesdeter- mined fromjustoneseasonof photometry. over time.Consequently,one might expecttherangedis- noting thatvirtuallyallofour47 variablesarestarspotvari- ables, wellknowntohaveamplitudes dramaticallyvariable 2932 HENRYETAE:CHROMOSPHERICALLYACTIVESTARS © American Astronomical Society • Provided by the NASA Astrophysics Data System 3 d ß 6 Wa Tau1 *Check starisvariable,seediscussion 'Originally compstarforHD202908,seediscussion ’Originally thesuspectedvariable *’Comp starforHD82286,seediscussion *More thanonepossibleperiod,seediscussion BD +36*2193 * AmplitudedeterminedfromFourierfit Comp starforHD148405,seediscussion 'Check staristhelowamplitudevariable6CrB(Fernie,J.D.1991,PASP, 103,1091) *Originally compstarforHD181391,seediscussion Comp starvariable,seediscussion '"Results fromBdataanalysis BD +70*959 BD +48*3686 BD +30*2130 "Check starforBD+30°2130,seediscussion 1E2349.8-0112 HD 122767 HD 118234 BD +13°13 BD -0°4234 HD 20295L HD 171488 HD 160934 HD 148127® HD 144110 HD 131511 HD 118981 HD 113816 HD 82443 HDE337518 HD 223971 HD 208472 HD 206301 HD 203387 HD 181475* HD 148405 HD 141690 HD 112859 HD 99267 HD 98800 HD 89546 HD 85091 HD 82286 HD 80953 HD 72429 HD 72146 HD 70573 HD 62668 HD 33363 HD 22694 HD 18645 HD 18632 HD 17925 HD 7205 HD 51066 HD 39743 HD 29697 Variable Star d d 148127 d 224037 212072 161937 100066 205784 223636 208916 203842 205829 202890 337653 122693 118865 117816 112570 284676 171286 143595 132296 113449 180086 161014 141732 Comp 29246 96778 98828 83098 90400 84722 48840 40084 32231 22072 80953 72075 71008 71136 61363 18145 18258 18690 HD 7590 1168 223825 212712 164613 204121 202671 224721 208513 206561 179422 202908’ 141714' 129972 123999 119126 111998 170829 160361 148554 144204 117266 111421 181391’ Check 99373 29169 98346 91480 85259 83821 45947 99267* 84179 72505 70458 60652 38104 33355 29169 23052 71093 16765 18262 18511 HD 1419 8007 Table 3.Photometricresults. 9245-9443 8898-9009 9638-9736 9365-9516 9374-9545 9285-9529 9703-9805 8944-9166 9415-9528 9103-9164 9285- 9 529 9697-9805 9638-9717 9638-9805 9262-9496 2440000 + 9236- 9 384 9245-9352 9486-9545 9235- 9 389 9235- 9 362 9234- 9 340 8757-9689 9096-9155 9481-9545 9481-9547 9481-9548 9319-9548 9356-9519 9646-9805 9638-9805 9252-9493 8899-9097 9256-9445 9638-9705 8382-8439 9352-9547 9347-9547 9008-9167 9081-9165 9262-9492 8905-9118 9638-9805 9236- 9427 9235- 9424 9235-9407 9284- 938 9407-9474 JD Range Notes toTABLE3 observation ofall47variables. Thestarswereobservedat Kitt PeakNationalObservatory (KPNO) withthecoudéfeed 175 100 107 112 128 125 142 141 We obtainedatleastonehigh-dispersion spectroscopic 41 56 42 83 53 47 19 20 68 67 33 64 30 38 56 99 71 39 35 39 35 98 94 38 82 87 75 90 39 92 82 87 84 29 50 32 48 91 81 4. SPECTROSCOPICOBSERVATIONS ANDANALYSES a 1 a 1 0.575'’ ±0.001 1.487* ±0.002 1.145 ±0.002 2.693' ±0.005 22.54 ±0.05 3.296 ±0.002 14.24 ±0.02 1.651'’ ±0.003 1.842' ±0.005 1.338" ±0.002 1.852^0.003 10.39 ±0.03 3.416 ±0.009 3.270 ±0.005 3.936 ±0.003 2.42* ±0.01 4.64 ±0.02 13.80 ±0.06 10.22 ±0.05 8.31 ±0.04 6.80 ±0.02 4.03 ±0.02 5.94 ±0.04 5.43 ±0.03 9.37 ±0.04 6.85 ±0.03 7.17 ±0.02 21.6 ±0.5 f 23.5 ±0.2 21.5 ±0.3 68.0 ±0.3 ß 28.5 ±0.1 69.7 ±0.5 41.5 ±0.2 14.8 ±0.2 21.6 ±0.6 73.1 ±0.6 2L3 ±0.4 12.1 ±0.2 18.5 ±0.4 16.2 ±0.3 56.9 ±0.8 96- ±1 97 ±3 64 ±1 53 ±1 31 ±1 Period (days) Amplitude ck-comp fc fc ß (mag) 0.015 0.015 0.04 0.12 0.08 0.03 0.04 0.03 0.03 0.23 0.01 0.20 0.08 0.10 0.03 0.06 0.05 0.01 0.03 0.03 0.06 0.10 0.02 0.05 0.05 0.01 0.04 0.09 0.16 0.23 0.17 0.12 0.03 0.05 0.06 0.01 0.36 0.04 0.05 0.05 0.17 0.04 0.02 0.03 0.03 0.02 0.03* d d d 0.008 0.007 0.006 0.005 0.004 0.005 0.008 0.005 0.008 0.004 0.005 0.006 0.005 0.006 0.005 0.004 0.005 0.006 0.004 0.004 0.004 0.005 0.008 0.007 0.007 0.008 0.005 0.006 0.008 0.008 0.007 0.006 0.004 0.008 0.005 0.008 0.007 0.004 0.008' 0.006 0.005 0.007 0.015 0.020* 2932 1995AJ 110.2926H 2933 HENRYETAL:CHROMOSPHERICALLYACTIVESTARS versus theamplitudeofvariabilitydiscoveredbydifferentialphotometric Fig. 1.ComparisonoftherangeVvaluesappearinginTable2(yaxis) wavelength rangeof80Â,aresolution0.21A,and monitoring (xaxis,circles=ourpaper,squares=previouslypublished).The the CailHandKlineswasobtained.Thatspectrumhasa straight lineindicatesperfectcorrelation. obtained ofthefainteststars.Foronestaranobservation also wereobtainedformanyofthestars.Thespectrahavea with thevastmajoritycenteredat6430Â.Oneortwoob- detector. Theobservationswereobtainedatredwavelengths telescope, coudéspectrograph,andaTexasInstrumentsCCD with theKPNOIRAFcross-correlationprogram,FXCOR wavelength rangeof56Âandaresolution0.2Â. signal-to-noise (S/N)ratioof100ormoreexceptforthose servations ofHaat6563Âandthelithiumline6708 the workofScarfeetal.(1990).Sinceadditionalobserva- tions willbeobtainedfornearlyallofthestars,wehavenot red-wavelength-region spectrawemeasuredthefullwidthat coverage. eccentricity, thetwoelementsofparticularinterestindiscus- binaries, preliminaryvaluesofonlytheorbitalperiodand quote anaveragevelocityplusitsstandarderrorandforthe later time.Instead,fortheconstant-velocitystarswesimply listed theindividualvelocities,whichwillbepublishedata (Fitzpatrick 1993).SeveralIAUvelocitystandards(Pearce half maximumofthreetosevenrelativelyunblendedfea- different becauseofalongerbaselineandimprovedphase final publishedvaluesofthoseelementswillbeonlyslightly from measurementsofmultiple spectra. value ofvsiniaswellanintercomparison oftheresults The estimateduncertaintydepends tosomeextentonthe for thespectraltypewasassumed fromtheworkofGray lines wereused.Instrumentalbroadeningwastakenintoac- while forspectrawithbroadlines,anyrelativelyunblended lines, weaktomodeststrengthunsaturatedlineswereused tures andaveragedthosevalues.Forstarswithnarrow our starswiththeprocedureofFekeletal.(1986).In sions ofsynchronousrotation.Invirtuallyallthecases velocity andmultipliedbyanempiricalconstantof0.591.To count andthentheremaininglinewidthwasconvertedintoa 1957) wereobservedandtheirvelocitiesassumedfrom obtain thefinalvsinivalue,a macroturbulence appropriate (1982, 1989),Soderblom(1982), orMarcy&Basri(1989). © American Astronomical Society • Provided by the NASA Astrophysics Data System Radial velocitiesfortheprogramstarsweremeasured We havedeterminedtheprojectedrotationalvelocitiesof -1 parisons avarietyofstandardswereusedwhosespectra the 6430-6465Âregionalongwithgeneralappearance priate inourdiscussions,themetalabundancesofstan- the standardsarelistedbyStrassmeier&Fekel(1990),al- wavelength regionisaveryusefulcriterion.Forthecom- of thespectrumasspectral-typecriteria.Inaddition,forK luminosity-sensitive andtemperature-sensitivelineratiosin of Strassmeier&Fekel(1990),whoidentifiedseveral were determinedbyvisualcomparison.Weusedthemethod have nearsolarironabundanceswithmostofthe[Fe/H] types ofthestandardsarefromKeenan&McNeil(1989) though additionalstarswereobserved,primarilyfromthelist obtained withthesametelescope-spectrograph-detector dwarfs thestrengthofwingssaturatedlinesinthis placed theabundancesfromnumerouspapers,mostofwhich unless otherwisenoted.Thevastmajorityofthosestandards of Keenen&McNeil(1989).Inourdiscussionsthespectral extremely usefulworkofTaylor(1991,1994),whohas dards arenoted.Theyhavecomefromtheextensiveand values rangingfrom-0.2to0.2.Althoughwedonothavea setup andhadtypicalS/Nratiosof200orgreater.Many our observationofsomemetal-poorbinaries.Whenappro- grid ofmetal-poorormetal-richstars,observationsafew et al.(1992),onaconsistentscaleandhascomputedmean such starshavebeenobtained,necessitatedparticularlyby difficult. Thus,thecomparisonspectrawerecreatedbya lined spectroscopicbinaries,avisualcomparisonbecomes abundance valuesandtheirassociatederrors. are alsoreferencedinthecompilationofCayreldeStrobel star isgreaterthanabout8kms,aswellfordouble- rapidly rotatingstarsthelineprofilesaremodifiedbyare- propriately summedandshiftedwhilethelinesarerotation- computer programdevelopedbyHuenemoerder&Barden classes whileourluminosityareuncertainbyhalfa the appropriatestandard. the linesappeartohaveflatbottomsandarenotasdeepin one starshowssignificantlineasymmetrieswhileinanother duced fluxfromcoolerstarspots.Thespectrumofatleast line-strength changesaresmearedout.Insomeofthemost creases, classificationbecomesmoredifficultsincemodest class. DiscussedinSec.6andflaggedTable4areafew of ourspectralclassificationsasoneorsometimestwosub- ally broadened.Wenotethat,asthelinebroadeningin- spectrum. Forabinarythechosenstandardspectraareap- simply rotationallybroadensthelinesofchosenstandard (1984) andBarden(1985).Forasinglestartheprogram with theirtechniqueindetermining themetallicitiesof et al.(1988).Latham(1988) notedsomedifficulties found byLairdetal.(1988),which wererepeatedinLatham cases wheretheuncertaintiesaregreater.Inseveralinstances dances thataremuchclosertothe solarvaluethanthevalues with caution.Likewise,whencompared withourstandards, x-ray sources.Weconcludethattheirtypesshouldbeviewed ent fromthosedeterminedbyFlemingetal.(1989)fortheir our spectralclassesand/orluminosityareverydiffer- some ofthemetal-poorbinaries appeartohavemetalabun- -1 For moststarswithvsin/=^8kmsthespectraltypes In caseswheretheprojectedrotationalvelocityofasingle For thevastmajorityofstarsweestimateuncertainty 2933 1995AJ 110.2926H 2934 HENRYETAL:CHROMOSPHERICALLYACTIVESTARS © American Astronomical Society • 6 HD 22694A HD 18645 HD 18632 HD 17925 HD 7205 HD 29697 HD 33363 HD 62668 HD 51066 HD 39743 HD 82286A HD 80953 HD 72429 HD 72146 HD 70573 HD 98800Aa HD 89546 HD 85091A HD 82443 HD 113816 HD 112859A HD 99267 HD 118981A HD 118234 HD 122767 HD 131511 HD 141690Aa HD 148405 HD 148127 HD 144110A HD 160934 Wa Tau1A HDE337518A HD 223971A Value fromliterature,seeindividual-stardiscussion “Ec =eclipse,Elellipticity,Ppulsation,Sspots,Uunknown BD +13°13A BD -0°4234A HD 208472 HD 206301A HD 203387 HD 202951 HD 181475 HD 171488 BD +70*959 BD +48*3686 BD +36°2193 BD +30°2130 const =constantvelocity SB =spectroscopicbinaryofunknown period "More thanonepossibleperiod,seeindividual-stardiscussion 1E2349.8-0112 : =Amoreuncertainquantity,seeindividual-star discussion Star B B B Ba B B B B Ac B B B B B 6 6 G2 III-IV Spectral G2 IV-V Kl IV-V K1 IV-V G1 IV-V G2-5: V K0 IIP K5: V K5: V KO: IV KO: IV G8 IIP G2 IV: G5-8V K7 Ha* G8 IV: K0 III K0 III K4 III G8 III G2: V: KO IIP Kim KO III KO III KO: V K3 III G2 V: late F K5: V K2: V K4 III K2 V K2 V K5 III G6 III Type K5: V G8 III G8 V G5: V late A G6 III G6 III K4 V G2 IV KO: V KO V FIV F9 V Kl V Kl V F9 V K7 V G8 V K3 V KO V K3 V KO V Kl V G8 V G6 V 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 const: (days) const: const: const const: const: const: const 125.4 const const const const const 8.65 6 1189 3.39 0.0 59.1 0.59 const const: const 4.67 14.5 0.48 const const const 13.17 52.5 20.9 2.73 50.P 0.0 1.67 315 83.1 3.76 262 69.3 6.57 1.84 21.3 7.15 23.7 ~0.0 18.7 22.6 ~0.0 SB SB SB: SB SB Table 4.Summaryofproperties. 6 6 6 6 6 6 6 6 Eccen. vsiniP 6 pJ 0.39 0.48 6 6 6 0.78 6 ~0.0 0.49 0.87 0.05 -0.0 0.06 ~0.0 0.18 -0.0 0.17 0.0 0.0 0.0 o.o 0.0 o.o Notes toTABLE4 1 Provided bythe NASA Astrophysics Data System (km s“)(days)(R 0 6 6 6 <11 <11 6 <3 <3 <3 5.5 <6 <6 6 40 93 35: 35: 16 14 11 14 15 17 26 22 17 33 50: 21 41 13 11 11 16 16 14: 19 16 19 8 7 7 8 9 7 4 6: 5 4 5 7 8 4 7: 7 4 4: 4 6 6 4 5 6 7 7 7 0.575" 3.296" 3.936 10.22 3.416 3.270 10.39 22.54 2.693" 1.651" 0.85 21.6 6.85 21.3 1.842" 41.5 7.17 14.24 1.338" 69.7 1.852" 28.5 1.487" 9.37 73.1 1.145" 21.5 16.2 23.5 5.43 4.64 5.94 18.5 14.8 4.03 56.9 21.6 68.0 13.8 8.31 6.80 53 12.1 2.42" 97 64 96 31 Rm, 19.3 12.8 11.6 15.2 3.4 0.5 1.1: 0.7 1.0 7.4 2.3 3.0 7.9 6.2 6.4 0.5 0.5 7.7 2.3 0.7 7.0 0.8 0.6 6.3 0.9 0.5 7.9 1.5 0.7 0.6 9.4 8.1 0.9 0.8 0.7 0.9 1.1 0.5 5.3 1.2 1.7 Rotation NumberMech.“ pseudo pseudo pseudo Sync. RossbyVar. likely likely yes yes yes yes yes no yes yes yes yes yes yes no yes yes no no no no 0.13 0.27 0.27 0.18 0.74 0.09 0.19 0.14 0.43 0.10 0.48 0.26 0.18 0.31 0.30 0.53 0.15 0.04 0.27 0.92 0.36 0.14 0.11 0.29 0.35 0.13 0.04 0.06 0.39 0.10 0.08 0.37 0.15 0.06 0.02 0.06 0.23 0.47 0.06 0.04 0.04 0.30 0.21 0.09 0.07 S,Ec,El S,Ec S,Ec U S S S S S S S S S S S S S S S s S S S S S P S s s S S S S S S S: S: 2934 1995AJ 110.2926H photometry andspectroscopy.Althoughthevastmajorityof more thanonecomponenthasbeendetectedspectroscopi- tem nameswithindividualbinarycomponentsidentifiedif the discussionofindividualstar.Column1listssys- troscopic analysesaswellpropertiesderivedfromour we haveanalyzedonlyonesuchbinary. lems, however,arenotthesourceofdiscrepancies,since double-lined binarieswithsimilarcomponents.Thoseprob- 2935 HENRYETAL.:CHROMOSPHERICALLYACTIVESTARS plete phasecoverageoftheorbitshasnotyetbeenobtained. the formalvalueisquitesmall,generally^0.03,butcom- orbital eccentricityisgivenincolumn4.Forseveralofour tected initsspectrum,itislistedasSB.Ifknown,the definitely variablevelocityordoublelineshavebeende- the literature.Ifnoorbitalperiodisknownbutstarhasa cally. Spectraltypesforthestarsaregivenincolumn2. identified byacolon;thereadershouldreferinsuchcasesto enced. Quantitiessomewhatmoreuncertainthantherestare information inthistablecomesfromourpresentwork, Table 3aregivenagainincolumn6.Allbuttwo,thosefor Results ofourvsinimeasurementsarelistedincolumn5, ity constancyisacombinationofourresultsandthosefrom the starissingle.Insomecasesourconclusionaboutveloc- identifies astarashavingconstantvelocity,indicatingthat Column 3liststheknownorbitalperiodofeachsystemor HD 99267and181475,arestarspotperiodshence in afewcasesasupperlimits.Photometricperiodsfrom systems theeccentricityislistedasapproximatelyzerowhen some casesvaluesfromtheliteraturearegivenandrefer- by rotationalmodulation.TheB—Vcolorindexappropriate number ^0.65isrequiredforastartohavelargespotsand for thosestars.Hall(1991,1994)hasshownthataRossby patches calledstarspots,theRossbynumber,ratioofro- result ofrotationalmodulationalate-type,henceconvec- column 10. pute theRossbynumber,asdiscussedbelow,foreachspotted computed, whenappropriate,fromthevaluesofprevious are assumedtoberotationperiods.Theminimumradius 99267 andHD181475)butis given fortwosinglelate-K two starsalmostcertainnotto bestarspotvariables(HD hence besignificantlyvariable(greaterthanabout0.01mag) tation periodtoconvectiveturnovertime,hasbeencomputed tive, starwhosephotosphericsurfaceismottledbydark determined whichstarsarerotatingsynchronously,pseudo- compared theorbitalandrotationperiodsofbinaries two columnsisgivenincolumn7.In8wehave of theprimarystarisused.No Rossbynumberisgivenfor composite spectraanddissimilar components,thespectrum for theobservedspectraltypeincolumn2isusedtoget depending ontheobservedluminosity class(Hall1991, color (Gilliland1985),whichisthenscaledupbyafactor convective turnovertimeforamain-sequencestarofthat star whilethemechanismsofvariabilityaresummarizedin synchronously, ornonsynchronously.Incolumn9wecom- 1994). Therotationperiodcomes fromcolumn6.Incasesof © American Astronomical Society • Provided by the NASA Astrophysics Data System Table 4summarizesforeachstartheresultsofourspec- Because weconcludethatmostofthestarsvaryasa 5. SUMMARYOFSTELLARPROPERTIES photometric amplitudeof0.009magisrightatthelevel period isidentifiedastherotationperiod, relatively small. but addedacolontoindicateourdilemma. photometric periodtobetherotationperiod,computed nism seeninsingleM-typegiantsextendstotheK-typegi- that thereisnosignificantevidencethepulsationmecha- conservation andmagneticbraking(Gray1989).Ifthevari- of rotationduetothecombinedeffectangularmomentum main-sequence evolutionshouldresultindramaticslowing giants withsurprisinglyshortphotometricperiods.Post- discussion. HD148127and202951aresingleK-type the thresholdbyonlyahair,butitsamplitudeof0.03magis the i?^0.65threshold.ForHD118981,Æ=0.92butits tometric variabilitywefindisinvirtuallyperfectaccordwith giants (HD148127andHD202951)thatmightbe.Thepho- have previouslybeendiscoveredasvariables:HD Rossby number,entered“5”(forspots)asthemechanism, Hall (1995)recentlyreviewedthisquestionandconcluded we canthinktoconsiderispulsation,butPercy(1993)and make largespotsavirtualcertainty.Theshortrotationperiod is easilyshortenoughthatthestar’sRossbynumbershould ability isattributedtospotmodulationandthephotometric ants. Forthesetwostars,therefore,wehavepresumedthe other mechanismforvariabilityinsingleK-typegiantsthat itself, however,remainsaproblemtounderstand.Theonly significance. ForHD7205,Æ=0.74,onthewrongsideof those casesournewobservationsturnouttobeextremely 223971, BD+13°13,and+70°959=ETDra.Intwoof the transferofcoreangularmomentum (seeFekel&Bal- presume thatthemechanismofvariabilityforHD148127 bright giantpulsatingvariable,whileHD99267seemstobe ellipticity effect.WepresumethatHD181475isalate-type HD 223971haveeclipseswhilealsoshowsthe found. InadditiontostarspotsHD62668,141690,and ity inthevastmajorityofcasesisrotationalmodulationa bers intheNewCatalogueofSuspectedVariableStars HD 62668,131511,andBD-0°4234haveNSVnum- mechanisms ofvariability.Ofthe47starsonlyV834Tau, while forHD233971wehavediscoveredtwoadditional nounced photometricperiodisanaliasofthetrue valuable. ForHD29697wefindthatthepreviouslyan- achandran 1993).Fekel&Bitter (1989)andHall&Henry of starswhoserapidrotationis suggested tohavecomefrom total includes7dwarfsand9giants (Table4).Someofthe number ofspottedvariables,16 (34%),aresingleandthis and HD20295lisaspottedrotatingsurfaceratherthanpul- ables (e.g.,Krisciunas1994;Hall1995).Asnotedabove,we a newlyfoundmemberofthepuzzlinggroupF0Vvari- spotted surface,othertypesofvariabilityhavealsobeen single giantsarenewlyidentified membersofasmallgroup of the47starsanalyzedinpresentwork,asubstantial sation. (Kukarkin etal1982).Althoughthemechanismforvariabil- spherically activestarshaveemphasizedbinaries.However, 17925=EP Eri,HD29697=V834Tau,98800, 0 0 The mechanismforvariabilityintwostarsrequiressome Of the47starsdiscussedinthispaper,followingsix Our previouspapersdiscussingphotometryofchromo- 2935 1995AJ 110.2926H -1 1 km s.Suchalowvsiniisconsistent withtheratherlong lines havelittleornorotational broadening,withvsin/^3 those ofourstandardsresultsin aclassificationofG8V.The tra ofHD7205.Avisualcomparison ofitsspectrumwith orbits; however,wedetectnosecondary featuresinourspec- period forachromosphericallyactivedwarf.Fromsevenob- ary ofthreethebinariesforwhich Fouts(1987)presented observations Stockton&Fekel(1992)detectedthesecond- this starhaveavelocityrangeof25kms“.Fromsimilar Though long,thisperiodisnotthelongestknownrotation the 21.3dayperiodshowanamplitudeof0.03mag(Fig.2). K fluxvariations. day periodfoundbyVaughanetal.(1981)foritsCanHand dredths ofamagnitudeontimescaleconsistentwiththe37 Cyg Ahasmodestphotometricvariationsofafewhun- the Bdatagavesameperiod.TheVplottedagainst tation periodisP=21.3±0.4days.Anidenticalanalysisof middle two-thirdsoftheobservingseason.Theresultingro- Periodogram analysiswasperformedonaportionoftheV was theweakCanemissioninspectrumofHD7205.In servations Dorren&Guinan(1982)claimedtheK5Vstar61 data thathadthemostcoherentlightvariation,roughly Fouts (1987)identifiedHD7205asasingle-linedspectro- tained V=7.254,—y=0.482,andC]0.339from pseudosynchronously rotating(Hut1981).InadditiontoHD gested thatthestarwasinlocalneighborhood.Sandage addition heclassifiedthespectrumGpandnotedthatitwas moted tofull-fledgedmembership. HD 118234,148405,andHDE337518shouldbepro- chromospherically activestarsthatareineccentricorbitsand rather unusualcircumstance. scopic binarybutfoundnoorbitalperiod.Strassmeieretal. Strömgren photometry.Fromahalf-dozenReticonspectra, & Kowal(1986)obtainedUBVphotometryofitasparta slightly weaklined.Halliwell(1979)hadpreviouslysug- qualify forinclusioninCCABSwhileHD7205,62668, light onsomeofthecandidatestarslistedinCCABSII.HD identified (Table4)HD118981and141490aspseudo- rotation isneithersynchronizednorpseudosynchronized,a survey ofhighproper-motionstarswhileOlsen(1993)ob- BD +36°2193,withorbitalperiodslessthan21dayswhose (1993) listedthestarasacandidateinCCABSII. seven. synchronous rotators,increasingthetotalofsuchsystemsto 39743, whichwasincludedinFekeletal.(1994),wehave ered foursystems,HD22694,33363,206301,and 2936 HENRYETAL:CHROMOSPHERICALLYACTIVESTARS active binariesaresynchronouslyrotating.Wehavediscov- (1990) showedthatthevastmajorityofchromospherically 18645, HD51066,and72146aresinglestarsthatdonot J Our threered-wavelengthspectroscopicobservationsof © American Astronomical Society • Provided by the NASA Astrophysics Data System We haveoneseasonofphotometricdataforHD7205. One ofBidelman’s(1985a)objective-prismdiscoveries The discussionsandresultsofthispapershedsignificant Fekel etal.(1994)updatedHall’s(1986)initiallistof 6. DISCUSSIONOFINDIVIDUALSTARS 6.1 HD7205 -1 ity whilefromfourCORAVEL-type velocitiesTokovinin more recentandnumerousvelocities ofBeavers&Bitter low-dispersion spectrogramobtained byPopper(1942).The period deducedfrommodulationofCailKemissioninten- could findintheliteratureisone discrepantvelocityfroma variable buttheonlyevidenceof velocityvariabilitythatwe Star Catalogue(Hoffleit1982)listsitsradialvelocityas what conflicting,rangingfrom3.3(Benz&Mayor1984)to At almostthesametimethatwebeganobservingit,Cut- determined vsinivaluesreportedintheliteraturearesome- days accordingtoBahúnasetal.(1983).Thewell- in V.Fromthosedatahesuggestedatentativeperiodof6.5 did showdefinitevariability,witharangeof6.03-6.08mag ispoto (1992)presenteddifferentialUBVRIphotometrythat Blanco etal.(1979)didnotindicatesignificantvariability. possible variable,thoughwithnorangeindicated,andPetit (1986) andYoungetal.(1987)show noevidenceofvariabil- our Table2andhisperiodisconsistentwiththerotation days. Hisrangeisconsistentwiththe0.08magseenin 8.1 kms(CayreldeStrobel&Cayrel1989).TheBright sity, 6.9daysaccordingtoVaughanetal.(1981)or6.6±0.1 and avariabilitytypeofBY.Differentialphotometryby mospheric activity,waswhatpersuadedustoplacethisstar nearby (8pcaway),veryyoung(afewmillionyearsold) other 46starsinourpaper.Itisofparticularinterestasavery determine itsorbitalelements. Additional spectroscopicobservationsarebeingobtainedto photometric periodthatwehavedeterminedforthisdwarf. on ourprogram.ItisthesuspectedvariableNSV975 acterize itasstrong.Thisstrongemission,indicativeofchro- the bestportrayalfoundinPasquinietal.(1988),whochar- types intheliteraturerangefromKOVtoK3V.TheCanH mag. from theephemerisHID2449200.0+21.3£.TheamplitudeinVis0.03 Fig. 2.LightcurveofHD7205plottedagainstphotometricphasecalculated (1990) laterspecifyingasuspectedrangeof0.06maginV and KemissionwasfirstnotedbyJoy&Wilson(1949),with K emission(CayreldeStrobel&Cayrel1989).Spectral K-type dwarfwithahighlithiumabundanceandCanH (Kukarkin etal.1982),withGolay(1973)firstlistingitasa % 0.66- HD 17925hasbeencitedinmorepapersthananyofthe 0.68 - 0.64 - 0 0.20.40.60.81.0 6.2 HD17925=HR857=EPEri Photometric Phase 2936 1995AJ 110.2926H -1 -1 -1 -1 -1 1 -1 -1 -1 2937 HENRYETAL:CHROMOSPHERICALLYACTIVESTARS period P=6.85±0.03days,confirmingthetentative found byCutispoto(1992).Thosedataareplottedversusthe odogram analysisofthefirstseason’sdatagivesrotation parallax fromtheneweditionofYaleParallaxCatalogue 0.03 mag. lated fromtheephemerisHID2449200.0+6.85£.TheamplitudeinVis Fig. 3.LightcurveofHD17925plottedagainstphotometricphasecalcu- Ha lineofHD17925ispartiallyfilledbyemission.Visual much likethefirst. mately 0.03mag.Thelightcurveforthesecondseasonlooks rotation periodinFig.3andrevealanamplitudeofapproxi- List ofVariableStars(Kazarovets&Samus1995)hasas- examination ofourred-wavelengthspectraresultsinaK2V signed itthedesignationEPEriandvariabilitytype“RS.” is 0"100±07002(s.e.)(vanAltena1995).The72ndName four additionalspectraobtainedin1994November.While mag (Gray1992),indicatesthat ourvaluefromtheparallax for aK2dwarf,6.3mag(Corbally &Garrison1984)or6.5 binary hypothesiscomesfromtherotationperiodwhich, have anorbitalperiodofmonthsoryears.Supportforthe troscopic binarywithnearlyequalcomponents,whichmay found byBenz&Mayor(1984).Thelinewidthvariations kms (Tokovinin1990),and8(Basil&Marcy ues of8.1kms(CayreldeStrobel&Cayrel1989),7.6 our 1991valuemightbeconsideredconsistentwiththeval- in 1991Novemberbutmeasuredvsin/^3kmsfrom (1992) judgeditsingle.Theweighted-meantrigonometric kms. Ifusin/=3, the rotationalinclinationis is distinctlydifferentandsimilartothevalueof3.3kms obtained 18.8±0.3kms“from22observations.Wefound good agreementwiththatofBeavers&Eitter(1986),who velocity of18.1±0.02kms.Suchanaverageisin spectral type,whichisidenticaltothatdeterminedbyWilson about 30°.Thetrigonometric parallaxresultsin minimum radiusof1.08Rq,significantlytoolargeforaK combined withavalueofvsin/=8kms,resultsin v sin/=5.7±1kmsfromfourdifferentspectraobtained K dwarfisassumed,theresulting rotationalvelocityis6.3 dwarf. Ifinstead,aradiusof0.85Rqmoreappropriatefor suggest thatHD17925isanunresolveddouble-linedspec- (1962). OureightobservationsofHD17925resultinamean 1994) determinedbyotherobservers,ourmorerecentvalue © American Astronomical Society • Provided by the NASA Astrophysics Data System We havetwoseasonsofphotometryforHD17925.Peri- Consistent withthephotometricactivitywenotethat > < = 6.0±0.04mag.Acomparison withcanonicalvalues Photometric Phase -1 -1 -1 -1 -1 Fig. 4.LightcurveofHD18632plottedagainstphotometricphasecalcu- HD 17925asabinary. the discordantvsinimeasurementsarestronglysuggestive our binaryhypothesis,itisnotconclusive.Thus,although lated fromtheephemerisHID2449200.0+10.22E.TheamplitudeinVis new radial-velocityobservationswillbeneededtoconfirm and thetrigonometricparallaxissupportive,speckleand/or is somewhatlarger.Whileitinthedirectionpredictedby only 0.02mag. ently singleG6IIIwithi;sin/<10kms.Earlier,G.R preceeding discussion,andso we classifyitasK2V.The Additional informationwasprovidedbyFavataetal.(1995), Kuiper (Bidelman1985b)hadclassifieditKl.Favataetal. phase curve,despitethesmallamplitude,suggestsafairly to beonly0.02mag.Theidenticalperiod,withintheuncer- with thisperiodappearinFig.4,wheretheamplitudeisseen who foundvsin/=11kmsfromthesamespectrumand source 1E0257.4+0733.Theyconcludedthatitisanappar- trigonometric parallaxof07034 ±07016(m.e.)(vanAltena observing season. tainties, wasfoundintheBdata.Therelativelycoherent P=10.22±0.05 days.Thedataplottedinaphasecurve odogram analysisoftheVdatafindsrotationperiod examine itfurther. of thespectraltypeandx-raynaturethisstarledusto concluded thattheknownparallaxof07034(vanAltena dwarf. Itscriticallineratiosand thegeneralappearanceofits km sfoundbyFlemingetal.(1989)butsignificantlyless cation asaconstant-velocitystar(Flemingetal.1989).We and giveanaverageof28.3kms,supportingitsclassifi- (1993) estimatedanupperlimittoitslithiumabundance. spectrum areverysimilartothat ofHD17925,thestarin of theredspectrumHD18632, itisobviousthatthe than thatofFavataetal.(1995).Fromavisualexamination find vsini^3kms,consistentwiththeupperlimitof10 stable spotdistributiononthestarduringnearly200day saturated lineshavesignificant wings,makingthestara 1995) clearlyidentifiesthestarasadwarf.Thecombination Fleming etal.(1989)identifiedHD18632withthex-ray We haveoneseasonofphotometryforHD18632.Peri- The velocitiesfromourtwospectraarealmostidentical 0.2 0.40.60.8 6.3 HD18632 Photometric Phase 2937 1995AJ 110.2926H -1 _1- -1 -1 is adouble-linedbinarywith periodof8.65daysanda motion stars,Lathametal(1992) discoveredthatHD22694 radius ofthestaris3.4/?,quiteconsistentwithaluminos- significant eccentricityof0.39. Followingthepreceptsof ity classofIVorIII-IV. kms andarotationalperiodof21.6daystheminimum Ha lineispartiallyfilledbyemission.Withvsini=8 classification andsoweclassifyitG2III-IV.Thecoreofthe weak HawingssuggestanintermediateIII-IVluminosity Her (G2IV,Strassmeier&Fekel1990)providesabetterfit to thespectrumofHD18645than/¿HerA(G5IV).The km s.Weslightlyreviseitsvsinito8±1Inthe ten spectrawedetermineaconstantvelocityof2.61±0.05 plitude ofvariabilityisaverymodest0.02mag.Thefirsttwo 6430 Âregionanappropriatelybroadenedspectrumof84 ditional long-termvariabilityisseeninthefirstseason. scopic resultsthaninFekel&Balachandran(1994).From observing seasonsgivesimilarresults,exceptthatsomead- gives P=21.6±0.6daysforitsperiodofrotation.Theam- were givenbyFekel&Balachandran(1994),wholistitasa four objective-prismspectra.Preliminaryresultsforthisstar candidate inCCABSII.Duflot&Rebeirot(1966)classifiedit tures inthespectrumofHD18645.Thus,itwasaddedasa G2III andfoundanaveragevelocityof-9kmsfrom fication ofFlemingetal(1989). value isconsistentwithadwarfratherthanthegiantclassi- mag. AsrecentlypointedoutbyFavataetal(1995),sucha ric periodis21.6days,andtheamplitudeinVonly0.02mag. Fig. 5.LightcurveofHD18645plottedagainstJuliandate.Thephotomet- abundance oflessthan1.0. sons areplottedinFig.5.Periodogramanalysisofthosedata single G5IVstarwithvsinz'=9kmsandaloglithium (1991) reportedthedetectionofCanHandKemissionfea- 2938 HENRYETAL:CHROMOSPHERICALLYACTIVESTARS 0 1995) andV=7.95fromTable2resultinM=5.6±1.0 i; © American Astronomical Society • Provided by the NASA Astrophysics Data System In thecourseofaspectroscopic surveyofhighproper- Here wegiveamoreextensiveaccountofourspectro- From anexaminationofobjective-prismplatesBidelman Our photometricdatafromthelastofthreeobservingsea- 1.36 1.33 Julian Date(2,440,000+) 9660 96809700 6.5 HD22694 6A HD18645 -1 no significantlymetal-poorsubgiant orearly-Kdwarfstan- our rotationperiodresultsinaminimum radiusof0.99R» u sinzof7±1kmsforeach componentcombinedwith depletion of-1.02foundby Lathametal(1992).The evolved or,iftheyarereallydwarfs,haveslightlyearlier that areslightlytoostrongaswelllinewings A fitwitheEri(K2V),whichisslightlymetalpoor the criticallineratiossuggestedaslightlylaterspectralclass. ponents resultedinareasonablefittomostlinedepthswhile has [Fe/H]=-0.04±0.08(Taylor1994),usedforbothcom- more thoroughanalysis,however,resultedincontradictions. tral typesbetweenKOVandK2forbothcomponents.A significantly toolargeforaKdwarf. Unfortunately,wehave appear tobeindirectconflictwith theverysignificantmetal comparison withourstandardsindicatedapproximatespec- poor. Pasquini&Lindgren(1994)foundstrongCanKline strengths withthespectraofstarshavingsuchabundances spectral classesthan£Eri.Reasonablefitstotheline strong. Thissuggeststhatthestarseitheraremodestly [Fe/H]=-0.20±0.06 (Taylor1994),producedlinedepths Surprisingly, spectrumadditionwithcrDra(K0V),which lines arerelativelynarrow.Asaresult,itwasthoughtthatthe calcium emission,and0.09magrangeinV(seeTable2)all spectral classificationwouldbestraightforward.Avisual chronous period(Hut1981)of4.30days. Figure 6showsthephasecurveplottedwiththisperiodbut Periodogram analysisofthefirstyeargivesP=7.17±0.02 indicate thatthissystemshouldhavephotometricvariability. emission andafilledHaline,identifyingitaschromo- variation. Theamplitudewasthenabout0.04mag.ob- 2449427, whenthelightcurveshowedmostcoherent with datarestrictedtotheJulian-daterangeof2449403- days. Thesecondyeargivesthesameresultwithinerrors. 0.04 mag. strengths ofthetwocomponentsaresimilarandbothsets spherically activebinary.Therelativelyshortorbitalperiod, [m/H]= —1.02indicatingthatthesystemisrathermetal Carney etal(1987),theyalsodeterminedametallicity lated fromtheephemerisHJD2449200.0+7.HE.TheamplitudeinVis Fig. 6.LightcurveofHD22694plottedagainstphotometricphasecalcu- served rotationperiodisquitedifferentfromthepseudosyn- <3 > 0 We haveobtainedtwoyearsofphotometryforHD22694. Our lonered-wavelengthobservationshowsthattheline 2.12 2.10 2.08 2.06 0.2 0.40.60.8 Photometric Phase 2938 1995AJ 110.2926H 2939 HENRYETAL.:CHROMOSPHERICALLYACTIVESTARS Fig. 7.LightcurveofHD29697plottedagainstphotometricphasecalcu- 0.17 mag. lated fromtheephemerisHID2449600.0+3.936£.TheamplitudeinVis dards forcomparison.Thus,althoughapproximatelycorrect, computed byLathametal(1992)areeachquitesmalland for each,shouldbetreatedwithsomecaution. our preliminaryclassificationofthecomponents,KlIV-V with itscombinedemissionrisingabovethecontinuum.De- an oldsystembutrathertheopposite.TheU,V,Wvelocities abundances, otherpropertiesindicatethatHD22694isnot stars listedintheirTable1.Pasquini&Lindgren(1994) stand outwhencomparedwiththevelocitiesofother very differentfromthecomputedpseudosynchronousperiod eccentric. Also,ourobservedrotationperiodof7.17daysis showed thattheCallKemissionofsystemisstrong, of 4.30days.Alltheabovepropertiesareunexpectedfor spite anorbitalperiodlessthan10days,theorbitisvery Instead, theyareconsistentwithamuchyoungersystem. Additional observationswillbeneededtodetermineifthis a systempresumedtobesignificantlyolderthantheSun. nary. Ca ilHandKemissionand,fromthat,suggestedthatHD 29697 wasprobablyanundiscoveredbinarywithashort type wasalreadyassigned,inThe67thNameListofVariable the designationV834TauasavariableofBYDraconis already beendiscoveredbyChugainov(1981)andalsothat ourselves hadoverlookedthefactthatvariability that Youngetal.(1989),Strassmeier(1993),andwe concluded thatHD29697hasaconstantvelocity.Itturnsout orbital period.Thisresultedinitsinclusionasacandidate system isaZAMSorperhapsevenpre-main-sequencebi- four otherindividuals,butwehave beenunabletolearnthe cited aprivatecommunicationfrom A.M.vanGenderenand munication fromR.G.M.Rutten, andinRutten(1986),who be foundinMarillietal.(1986), whocitedaprivatecom- From hisdatahefoundapossible photometricperiodof one nightwhenitsmagnitudewasabout0.25magfainter. Chugainov (1981)hadarangeof0.12maginVexceptfor CCABS II.However,Pouts&Sandage(1986)hadalready Stars (Kholopovetal.1985).Thevariabilityobservedby 1.3290 days.Avalueof4.0days fortherotationperiodcan © American Astronomical Society • Provided by the NASA Astrophysics Data System Besides ourspectrum-additionresultsthatsuggestsolar Young etal.(1989)hadnoteditsexceptionallystrong > -0.75 -0.80 - -0.85 - -0.70 -0.65 0 0.20.40.60.81.0 6.6 HD29697=V834Tau Photometric Phase _1 -1 -1 -1 Fig. 8.AportionofthespectrumHD29697inHaregionwith relative intensityplottedvsrestwavelength.WhilethecoreofHo;isin found intheliteratureisK3V.Thestaranearbyneighbor ment onthespectraltype.Thepredominantclassification real sourceofthisdetermination.Thereseemstobeagree- emission, thelinewingshavealsobeenfilledbyemission. having atrigonometricparallaxof07074(vanAltena1995). note thatthe5-VofUpgren&Lu(1986),listedinTable2, Table 2showsuchasmallrange,only0.03maginV.We Given therangeofvariabilityobservedbyChugainov two seasonsofphotometryresultsinP=3.936±0.003 is outoflinewiththeothersandmaybeanerror. days. ThephasecurveforthosedataisplottedinFig.7. (1981), itisperhapsabitsurprisingthatthevaluesinour photometric phases0.8and1.0indicatessomecycle-to-cycle is ratherlargeforadwarf.Theobservedscatterbetween amplitude ofthelightcurveisapproximately0.17magand In bothseasonsthesuggestedperiodofChugainov(1981)is ing thefirstobservingseasonbutwithasomewhatsmaller variation overthecourseofsecondobservingseason. has aconstantvelocity.Acomparisonofthecenter-of-mass amplitude. Thelargeramplitudeinthesecondseasonre- velocities ofthreebinariesobservedbybothFouts(1987) is 6kmslessthanthevalueobtainedbyFouts&Sandage age radialvelocityof1.1±0.2kms.Thisaverage sulted fromafurtherdecreaseinthebrightnessatminimum. Similar behaviorhavingthesameperiodwasobserveddur- seen asanalias. equivalent widthabovethecontinuum is0.2Âcomparedto modest emissionabovethecontinuum (Fig.8).Ouremission less than2kmsineachcase.Thus,avelocitydifference and Stockton&Fekel(1992)showsvelocitydifferencesof et al.(1989)ourspectrumofHa showsthatHD29697has cation ofWilson(1962).Similar totheresultsofRutten classified itK4V,ingoodagreement withtheK3Vclassifi- long-term variation.AvisualcomparisonofourHD29697 of 6kmsforHD29697mayreflectarealbutperhaps (1986), whoconcludedfrom20observationsthatHD29697 its linesinthe6430Âregionhave strongwings,sowehave spectrum withseveralKdwarfstandardsshowsthatmanyof For HD29697,periodogramanalysisofthesecondour From threespectroscopicobservationsweobtainanaver- 2939 1995AJ 110.2926H 1 -1 2940 HENRYETAL:CHROMOSPHERICALLYACTIVESTARS ric periodis41.5days,andtheamplitudeinV0.12mag. mospheric activity,thelithiumlineisvisibleandhasan Fig. 9.LightcurveofHD33363plottedagainstJuliandate.Thephotomet- combined withtherotationperiodresultsinaminimumra- determine usin/^Tilkms“.Thisrotationalvelocity mospheric activity,significantrotation,anddetectionofthe about 50°. dius of0.54Rq,whichleadstoarotationalinclination 0.33 ÂfoundbyRuttenetal(1989).Fromthreespectrawe ZAMS. Tocomparethisfieldstarwiththelithiumabun- equivalent widthof79mÂ.Thecombinationstrongchro- lithium lineindicatesthatthestarisquitecloseto which fromtheirTable2resultsinaloglithiumabundance dances ofsimilarclusterstarsinthePleiades(Soderblom implying thatHD29697hasanagesimilartothePleaides. of 0.95.Suchamodestabundanceisquitecompatiblewith et al1993a),weassumeaneffectivetemperatureof4450K, has relativelylittlelithium.Aspartofanextensive cause ofitsemissionfeaturesandthedetectionvelocity dispersion spectrogramStrassmeier(1994)recentlycon- Soderblom etaLs(1993a)lithiumvaluesofmid-Kstars, <3 > given byFekel&Balachandran(1994),whoclassifieditasa variability fromourinitialspectra,itwasaddedtoCCABSII. firmed thattheHandKemissionisrelativelystrong.Be- sion inHD33363,thelimitedinformationknownaboutthis K0 IIIbinarywithvsin/=9kmsandalsonotedthatit star suggestedthatitwasunremarkable.Fromahigh- maximum andminimumbrightness. Thisisalsotrueinthe 9. Periodogramanalysisgives arotationperiodP=41.5 obtained inoursurvey.Thesecond seasonisplottedinFig. Several ofthepreliminaryresultsstatedinCCABSIIwere first seasongivesasimilarperiod andamplitude.Ascanbe Strömgren-photometry surveyofG5-typeHDstars,Olsen seen inFig.9,thereareslight cycle-to-cyclevariationsin (1993) obtainedV=7.55,Z?-y=0.682,andc^O.324. ±0.2 dayswhiletherangein brightness is0.12mag.The © American Astronomical Society • Provided by the NASA Astrophysics Data System As mightbeanticipatedfromtheevidenceofstrongchro- Until Bidelman’s(1991)detectionofCailHandKemis- Two seasonsofphotometricdataandpartathirdwere -0.30 -0.35 -0.40 -0.25 9250 9300935094009450 Julian Date(2,440,000+) 6.7 HD33363 -1 -1 -1 ries. Infact,ofthe94binarieswithorbitalperiodslessthan unusual circumstanceamongchromosphericallyactivebina- orbital periodisonlyone-halftherotationperiod,ahighly eccentricity is0.06,makingtheorbitalmostcircular.Suchan nary. Ourpreliminaryorbitalperiodis20.9dayswhilethe lengths showthatthestarisasingle-linedspectroscopicbi- ness variationoverthe2.5yrtimespanofourphotometry. first season,andtheremayalsobesomelong-termbright- found only7%wereasynchronouslyrotating.Suchverydif- nous rotatorXAnd,whoserotationperiodisalsomuch ferent rotationalandorbitalperiodssuggestitmaybeinthe propriately broadenedspectrumofßGem(K0III)provides km sdeterminedbyFekel&Balachandran(1994).Anap- ment ofadditionalspectraconfirmstheusin/9±1 longer thanitsorbitalperiod,54.0vs20.5days.Measure- 30 daysthatwerelistedinCCABS/,Fekel&Fitter(1989) in byemission. quite consistentwithourluminosityclassification.TheHa absorption featureofHD33363appearstobeslightlyfilled and rotationperiodresultinaminimumradiusof7.4R, a verygoodfittothatofHD33363.Themeasuredvsini same kindofevolutionarystateasthewell-knownasynchro- emission ofHD39743.Asaresult,itwasplacedonthe vatory wheredetectionofitsleisurelyvelocityvariations found vsin/=9kmsandamoderateloglithiumabun- elements (e.g.,P=83.2days,e0.18)thatarelistedin dance of1.2.TheF8IIIclassificationlistedbyDempsey Balachandran (1994)classifiedthestarG8III.Thelatteralso Our additionalobservationsledtothepreliminaryorbital others forHD39743.Theobservationsthefirstfullsea- et al.(1993)ispresumablyamisprint. suggested anorbitalperiodofatleastamonth(Lyons1988). spectroscopic observingprogramattheDavidDunlapObser- value intheotherseasons.Figure10showsapronounced variability is0.17mag.Theamplitudeonlyabouthalfthat shown byStrassmeier(1994).Halliday(1955)andFekel& curves duringthefollowingtwoseasonsrevealthat indicating thepresenceofmorethanonespottedarea.Light asymmetry nearthebrightnessmaximaforfirstseason, season givesaperiodof73.1±0.6days,andtheamplitude son areplottedinFig.10.Periodogramanalysisforthisfirst CCABS II.ItsmoderatelystrongCailHandKemissionis asymmetry developedintoashallowsecondaryminimum. G8 III,atypeincompleteagreement withthatofHalliday confirms Fekel&Balachandran’s (1994)spectraltypeof values oftheperiodandeccentricity(Table4)areonly dran (1994).Thevsiniandrotation periodresultinamini- single-lined binarytorefineitsorbitalelements.Ourpresent slightly differentfromthepreliminaryvaluesgivenin Q (1955). Fromanalysisofadditional spectra,wefindvsini CCABS II.Avisualreexamination ofred-wavelengthspectra = 8±1kms,slightlylessthan thatofFekel&Balachan- High-dispersion spectroscopicobservationsatredwave- Bidelman (1983a)detectedthefairlystrongCailHandK We havetwofullseasonsofphotometryandparts We continuetoobtainspectroscopicobservationsofthis 6.8 HD39743=HR2054 2940 1995AJ 110.2926H _1 -1 1 _1 2941 HENRYETAL:CHROMOSPHERICALLYACTIVESTARS Fig. 10.LightcurveofHD39743plottedagainstJuliandate.Thephoto- Fekel eta/.’s(1994)updateofHall’s(1986)list,HD39743 metric periodis73.1days,andtheamplitudeinV0.17mag. was identifiedasafifthchromosphericallyactivebinarywith ments, thepseudosynchronousrotationperiod(Hut1981)is luminosity classification.Fromourpreliminaryorbitalele- mum radiusof11.6R,whichisconsistentwithour one componentasapseudosynchronousrotator. 69.5 days,within5%oftheobservedrotationperiod.In They concludeditisanapparentlysinglestar,classified optical counterparttothex-raysource1E0657.6+7529. on itsx-raypropertiesisgivenbyStockeetal(1991).From Kl V,andfoundvsin/=43kms.Additionalinformation found HD51066tohaveCaIIHandKemission.Asaresult, Fekel &Balachandran(1994)identifieditasasingleK0III it becameacandidateinCCABSII.Fromhigh-dispersion an examinationofobjective-prismspectraBidelman(1991) ably ofinterstellarorigin,implyingthatthestarisagiant. best cycle-to-cyclecoherenceinthedataset,areplotted cj =0.432. abundance of1.5.Olsen(1993)observeditintheStrömgren star withvsin/=40kmsandasignificantloglithium sion featureseachhaveacentralabsorptionfeature,presum- spectrum Strassmeier(1994)notedthattheHandKemis- Q Fig. 11.PeriodogramanalysisofthosedatagivesP=16.2 terval Juliandate2449407to2449474,whichdisplayedthe obtained inoursurvey.Theobservationsforthe67dayin- system andobtainedV=6.956,/?—y=0.614 not beensuperseded.TheHa absorptionfeatureofHD this interval,is0.05mag.Significantcycle-to-cyclechanges in amplitudeareobservedovertherestofdatasetand longer-term brightnessvariationsarealsopresent. 51066 issomewhatfilledbyemission. Whilethevsin/isin of —21.1±0.4kms".Theresults ofFekel&Balachandran and 1993Aprilindicatethatthe starhasaconstantvelocity (1994), vsin/=40±2kmsand spectraltypeK0III,have ±0.3 days.Theobservedamplitude,atamaximumduring > < © American Astronomical Society • Provided by the NASA Astrophysics Data System Table 1ofFlemingetal(1989)listsHD51066asthe Two fullseasonsofphotometricdataforHD51066were Eight spectraobtainedatKPNO between1991November 8900 Julian Date(2,440,000+) 6.9 HD51066 9000 9100 Fig. 11.LightcurveofHD51066plottedagainstJuliandate.Thephoto- metric periodis16.2days,andtheamplitudeinV0.05mag. ric periodresultsinaminimumradiusof12.8’consistent we confirmthestarissingle,classifyitagiantratherthan excellent agreementwiththatofFlemingetal.(1989)and classification ofFlemingetal.(1989). with thegiantclassificationandincompatibledwarf ber ofasmallgroupmoderatelyrapidlyrotatingchromo- from futureeditionsofthecatalog,itis,nevertheless,astar a dwarf,inagreementwiththesuggestionofStrassmeier of particularinterest.HD51066isanewlyidentifiedmem- (1994). Thecombinationofourvsin/valueandphotomet- transfer ofangularmomentumfromarapidlyrotatingcoreas dance ofmanythosestarsissuggestedtocomefromthe spherically activesinglegiants(Fekel&Balachandran opposed tothebinarycoalescencescenariosuggestedforFK Comae (Bopp&Rucinski1981;BoppStencel1981).The imaging. large rotationalbroadeningmakesitacandidateforDoppler the reportofBidelman(1991)thatspectrumHD new variablestarwitharangeinphotographicmagnitudeof detection, itwaslistedasacandidateinCCABSII.Working 62668 showsCallHandKemission.Asaresultofthat 1993). Therapidrotationandrelativelyhighlithiumabun- this work,givesitthedesignationNSV3726,andclassifies of SuspectedVariableStars(Kukarkinetal.1982)references at SonnebergObservatory,Hoffmeister(1949)claimeditasa translating thisinformation,listsHD62668asapulsating as typeL:,where“L”means“slowirregularvariable”and 8.3-8.9 andapossiblemoderateperiod.TheNewCatalogue variable. Althoughwediscoveredthesystemtohavetwo ion areeasilydetectableand approximately0.08and0.15 otherwise unseen(presumablyhotter) spectroscopiccompan- 0.05 maginthesecondseason. Inaddition,eclipsesofthe two seasons.Itslightcurveshows rotationalvariabilitywith Table 2shows,wecouldfindnopublishedUBVphotometry. types ofvariability,neitheristheresultpulsations.As an amplitudeof0.23maginthe firstseasonbutonlyabout Although thiscandidateinCCABSIIshouldbedropped ^ -0.54 The impetusforourworkonthisinterestingsystemwas We havebeenobservingHD62668 photometricallyfor means “possible.”TheSIMBADdatabase,apparently -0.50 -0.52 -0.56 -0.58 9400 9420944094609480 Julian Date(2,440,000+) 6.10 HD62668 2941 1995AJ 110.2926H 2942 HENRYETAL:CHROMOSPHERICALLYACTIVESTARS riodogram analysisofthosedatagivestherotationperiod Fig. 12.FirstseasonlightcurveofHD62668plottedagainstJuliandate ted inFig.12.Thedistinctlyasymmetricshapeofthelight between 3.4and6.9days.Nosecondaryeclipseisapparent hotter companionareseenatphase1.0andhaveaduration ted againstorbitalphaseinFig.13,whereeclipsesofthe P =69.7±0.5days.Datafromthesecondseasonareplot- curve indicatestwospottedareasatdifferentlongitudes.Pe- observing season,excludingthefeweclipsepoints,areplot- mag deepinVandB,respectively.Thedatafromthefirst and theamplitudeinVis0.23mag. with thefeweclipsepointsnotplotted.Thephotometricperiodis69.7days, provided byanHalinethatissignificantlyfilledemis- by differentialrotation,tocausethedouble-humped,lower- from thefirstseason,lightcurvenowshowstwomaxima lines ofonlyonecomponentarevisible.Ourpreliminary of thetwoseasonsarecomparable,soaroughlyconstant and minimaperrotationoftheKstar.Themeanmagnitudes at phase0.5.Whiletherotationalamplitudeismuchreduced Eclipse pointsafewpercentdeepare seenatphase1.0.Therotational phase calculatedfromtheephemerisr(conj.) =2449177.3744+69.323£'. Fig. 13.Secondseasonlightcurveof HD62668plottedagainstorbital amplitude lightvariation. sion. Atredwavelengthsnear6430ÂandHa,broadened spotted areahasbeenredistributedaroundthestar,possibly two minima. amplitude inVhasdecreasedto0.06mag, andthelightcurvehasdeveloped < > > < © American Astronomical Society • Provided by the NASA Astrophysics Data System Additional evidencethatHD62668isanactivestar 2.10 2.15 2.20 Julian Date(2,440,000+) -1 1 -1 -1 binary. AnappropriatelybroadenedspectrumofßGem relatively long-periodorbitiscircularized.Thissystemhas the longestorbitalperiodofanyknowneclipsingRSCVn 0.05 mag. Fig. 14.LightcurveofHD70573plottedagainstphotometricphasecalcu- orbit. Thus,thevisiblecomponentissynchronizedand lated fromtheephemerisHJD2449200.0+3.296L.TheamplitudeinVis large minimumradiusof19.3Rq.Ifamass3is orbital elementsindicateithasa69.3dayperiodandcircular Thus, thesystemappearstobeamoremassiveanalogofHD cates thattheunseenspectroscopicsecondaryisalate-Astar. assumed fortheKgiant,massfunctionoforbitindi- v siniof14±2kmsandlongrotationperiodresultina phase plotshowsobviousandverycoherentlightvariations. Despite themodestrotationalamplitudeof0.05mag, the firstseasonwith3.296dayperiodisshowninFig.14. weaker possibilityat1.432±0.001days.Thephaseplotfor tation periodP=3.296±0.002daysandasomewhat counterpart tothex-raysource1E0820.2+0201.Theyclas- (K0 III)providesanexcellentfittothatofHD62668.The region wecannotdifferentiate betweenanearly-Gdwarf clusion ofFlemingetal.(1989)thatthisstarisapparently three yearsandhavenearlyidenticalradialvelocities,the The lightcurveforthesecondseasonisverysimilar. seasons. Periodogramanalysisofthefirstseasonfindsaro- sified itasanapparentlysingleG6Vstarandfoundvsini those ofHR483(G1.5V).Unfortunately, inthiswavelength its spectruminthe6430Aregionarenearlyidenticalto termined byFlemingetal.(1989).Thecriticallineratiosof average ofwhichis19.8±0.1kms“.Theysupportthecon- consistent withthatofadwarf (Olsen1984).Ourspectral to G2V:becausethecvalueof HD70573(Olsen1993)is G2IV-V. InTable4werevise theluminosityclassification and subgiant.Thus,fromourspectra aloneweclassifyitas V= 8.74,Z?—y=0.405,and^0.319. single. Itsvsin¿is11±1kms,slightlylessthanthatde- 155638=V792 Her(Fekel1991;Nelsonetal.1991). = 14kms.Olsen’s(1993)Strömgrenphotometrygives l Fleming etai(1989)identifiedHD70573astheoptical Our photometricdataforHD70573covertwoobserving Our threespectrogramsofHD70573coveratimespan 6.11 HD70573 Photometric Phase 2942 1995AJ 110.2926H _1 _1 2943 HENRYETAL:CHROMOSPHERICALLYACTIVESTARS Fig. 15.LightcurveofHD72146plottedagainstJuliandate.Thephoto- > results inaminimumradiusof0.7Rq,alsoconsistentwith metric periodis28.5days,andtheamplitudeinV0.16mag. < inclination isabout45°. class issomewhatearlierthanthatfoundbyFlemingetal a solar-typedwarf.IftheactualradiusislR,rotational candidate inCCABSII.Strassmeier’s(1994)spectrumofthis whose spectrumhasCanHandKemissionlines(Bidelman (1989). Thecombinationofourusiniandrotationperiod reach thecontinuum.Fekel&Balachandran(1994)found the startobeasingleG8IIIwithvsin/=14andsignifi- star showsverystrongCailHandKemissionfeaturesthat cant lithiumabundance.StrömgrenphotometrybyOlsen behavior isseenintheotherseasons. cycle-to-cycle variationsinamplitudeareevident.Similar The maximumphotometricamplitudeis0.16mag,and Fig. 15.PeriodogramanalysisgivesP=28.5±0.1days. tometry forHD72146,thesecondfullseasonisplottedin 1991). Asaresultofthisdetection,thestarisnotedas provides anexcellentfittothespectrumofHD72146.Mea- red wavelengthsabroadenedspectrumofkGem(G8III) and 1994Novemberthisstarhasaconstantvelocityof—1.2 (1993) gaveV=7.28,b-y=0.601,andc^O.374. Q km s.Therotationperiodandlinebroadeningresultina part toanx-raysource,1E0830.3 +1126,byFlemingetal. most suchstarsofthatgroup(Fekel&Balachandran1993), moderately rapidlyrotatingsinglelate-typegiant.Unlike minimum radiusof7.9R.Thus,likeHD51066,itisa surement ofadditionalspectraconfirmstheirvsin/14±1 the HalineofHD72146issignificantlyfilledinbyemis- tinuum. shows ablueshiftedemission peak risingabovethecon- sion, whichvariesinstrength.Oneofthreesuchspectra ±0.2 kms.AsfoundbyFekel&Balachandran(1994),at Q © American Astronomical Society • Provided by the NASA Astrophysics Data System HD 72146isyetanotherpreviouslyunremarkablestar From nineKPNOobservationsbetween1991November Of ourtwofullseasonsandpartialofpho- HD 72429isanotherstaridentified asanopticalcounter- 6.12 HD72146 6.13 HD72429 -1 _1 -1 Fig. 16.LightcurveofHD72429plottedagainstphotometricphasecalcu- only 0.015mag. lated fromtheephemerisHJD2449200.0+9.37£'.TheamplitudeinVis Strömgren photometrybyOlsen(1983)resultedin riod isseenintheBdata.Thephaseplotagainstthisperiod HD 72429.PeriodogramanalysisoftheVdatashowsadis- sified itsspectrumGOIII,andobtainedvsiniof14kms. (1989). TheyconcludedHD72429isapparentlysingle,clas- is showninFig.16.Theamplitudeoftherotationalmodu- tinct periodicityatP=9.37±0.04days.Theidenticalpe- spectral typeofsgGO. (1980) haduseditsunusualStrömgrenindicestosuggesta V=7.946, Z7-y=0.445,andC!0.421.EarlierOlsen lation isquitesmall,onlyabout0.015mag. From sixobservationsobtainedbetween1992Juneand1995 emission, showingthatthestarischromosphericallyactive. April, wegetameanvelocityof79.1±0.4kms,support- meier &Fekel1990).Unfortunately,thespectraofearly-G 72429 mostcloselyresemblesthatof84Her(G2IV,Strass- found byFlemingetal.(1989).TheredspectrumofHD ing theclaimofFlemingetal.(1989)thatstarissingle. dwarfs andsubgiantsinthe6430Âregionarenearlyiden- Our usin/of16±2kmsconfirmstherapidrotation with countsplottedvsrestwavelength. Fig. 17.AportionofthespectrumHD 72429intheCanHandKregion One seasonofphotometryfromoursurveyisinhandfor Figure 17showsourspectrumofthestar’sCaIIHandK 2943 1995AJ 110.2926H -1 _1 1 2944 HENRYETAL:CHROMOSPHERICALLYACTIVESTARS compared withGOIIIofFlemingetal(1989).Olsen(1980) bining ourvsiniwiththerotationperiodof9.37daysre- our spectraaloneweclassifyitasG2IV-V.However,com- Fig. 18.LightcurveofHD80953plottedagainstphotometricphasecalcu- estimated asubgiantluminosityclassfromhisStrömgren is notadwarf,andsoinTable4wehaverevisedittoG2IV: tical sowecannotdiscriminatebetweenthoseclasses.From mag. are inthesenseHD80953minus84179.TheamplitudeBis0.03 lated fromtheephemerisHID2449600.0+97E.Differentialmagnitudes indices. sults inaminimumradiusof3.0Æ>indicatingthatthestar velocity of79kmsindicatesthestarisratheroldbut,if question aboutitsevolutionarystatus.Theverylargeradial rotation neededtoproducestarspot variability,butthecon- from Young(1945)andK2IIIinTheBrightStarCatalogue found tobevariable.AsidefromtheHD-catalogtype, the HertzsprungGaplostitsangularmomentum?Coulditbe that isthecase,whyhasn’tthissinglestaronbluesideof CQ minus HD84179,whichweresomewhatcleanerthantheV but notconcludingthatitwasavelocityvariable. consistent withamid-Kgiant.Young(1945)gave8.1kms only spectraltypeswecouldfindintheliteratureareK3 which weusedasthecomparisonstarforHD82286andalso Comae? a coalescedbinary,theevolutionarystatussuggestedforFK long. Thus,asTable4shows, the RossbynumberforHD vective turnovertimeforaK-type giantiscorrespondingly type laterthanK2III,confirmed byourclassificationbelow. total rangeof10kms'"wassomewhatgreaterthanexpected < One mightregard97daysas rather longforthe“rapid” days. Thosedataareplottedagainstthe97dayperiodinFig. data, wereused.PeriodogramanalysisresultsinP=97±3 as ameanoffourradialvelocitymeasures,notingthatthe 80953 is<0.65,namely,0.27. (Hoffleit 1982).Brownetal.(1989)usedTandMvalues 18. Theamplitudeisabout0.03mag. 0 eu © American Astronomical Society • Provided by the NASA Astrophysics Data System The abovepropertiesofHD72429poseasignificant Relatively littlehasbeenpublishedaboutHD80953, The B—VandU-Bcolors(Table2)implyaspectral In thisinstance,ourphotometricBdataofHD80953 6.14 HD80953=HR3722 Photometric Phase -1 _1 1 -1 found byYoung(1945)anddiffers4kmsfromhis tudes areinthesenseHD82286minus84179.TheamplitudeVis Fig. 19.LightcurveofHD82286plottedagainstphotometricphasecalcu- mean value.ThespectraltypeofHD80953isclearlylater 0.09 mag. lated fromtheephemerisHID2449600.0+3.270£.Differentialmagni- ß Cnc(K4III)andHR4954(K5III).WeclassifyitasK4III than thatofeCrB(K2III)andisquitesimilarto metric periodresultsfromrotation,theminimumradiusis certainty istheresultoflinecrowding,whichmakesitdiffi- and determinevsin/=4±2kms.Therelativelylargeun- 80953. Ourradialvelocityof12.2kms“iswithintherange indicating thatitisindeedaveryactivelate-typesystem. 7.7 R. cult tofindweakunblendedlines.Assumingthatthephoto- riodogram analysisforHD82286isofthevariableminus Strömgren photometrybyOlsen(1993)resultedin counterpart oftheROSATwide-fieldEUVEsourceREJ0933 half asstrongtheprimary.We estimatesimilarvsinfs, been completelyresolved.Linesofthesecondaryareabout mum nearphase0.9. very asymmetrical,withasuggestionofsecondarymini- check stardataandgivesarotationperiodP=3.270 & Mulliss(1994)haveobtainedspectroscopicobservations & Bopp(1994)forevidenceofchromosphericactivity. may beacandidateforDoppler imagingdespiteitsfaintness double-lined binaryalthoughsofarthecomponentshavenot amplitude isabout0.09magwhilethelight-curveshape 80953 provedtobephotometricallyvariable.Thus,ourpe- about 35kmsforeachstar.The linesoftheprimaryshow 82286. However,bothHD82286anditscomparisonstar spectrum ofHD82286somewhat difficulttoclassifyal- and double-linednature.The above propertiesmakethe significant asymmetriesdueto spotsand,thus,thesystem V=8.351, —y=0.628,andc^O.229. +624, makingitsimilartootherstarsexaminedbyMulliss ±0.005 days.ThephasecurveisshowninFig.19. 0 We haveobtainedonered-wavelengthspectrumofHD We haveonefullseasonofphotometricdataforHD Pounds etal.(1993)identifiedHD82286astheoptical Our spectroscopicobservationsshowHD82286tobea 6.15 HD82286 Photometric Phase 2944 1995AJ 110.2926H _1 2945 HENRYETAL.:CHROMOSPHERICALLYACTIVESTARS Fig. 20.LightcurveofHD82443plottedagainstphotometricphasecalcu- 0.06 mag. lated fromtheephemerisHID2449600.0+5.43E.TheamplitudeinVis nously rotatingand,thus,theorbitalperiodshouldbeabout giants. Theapproximatespectraltypeoftheprimaryis though thecritical-lineratiosindicatethatstarsaresub- with thesubgiantclassification.Improvementinsuchpre- KO IVwhilethatofthesecondaryissimilar.Withsucha liminary resultswillbemadeoncesufficientadditionalspec- 3.3 days.Thecombinationofvsiniandrotationperiodre- short rotationperiodthesystemisalmostcertainlysynchro- troscopic observationshavebeenobtained. sults inaminimumradiusof2.3R,whichisconsistent § ^ 0.10- HD 82443isoneofthestarsBahúnasetal.(1995)aremoni- Using suchinformation,Griffin(1994)discussedtheproper- confirmed theresultofDuquennoyetal.(1991)thatHD continuing theseminalworkofO.C.Wilson.Griffin(1994) toring todetermineCailHandKlong-termemissioncycles, its CailHandKemissioninanobjective-prismspectrum. of itsCanKemissionfeature.Bidelman(1991)laternoted stellar activity(e.g.,Vaughan&Preston1980;Soderblom pointed outthattheassumedspectraltypeofKOVwas tion periodof2.5days,whichwaspredictedfromitsemis- ties ofHD82443inthecontextSoderblom’s(1985)rota- unlikely thattherotationperiodisasshort2.5days.He 82443 issingleandalsomeasuredvsin/=4.6±1kms. known parallaxof07054(vanAltena1995).Wesuspectthat likely theresultofcombiningHDclassificationwith the V=1.\0maglistedbyPanagi&Mathioudakis(1993) sion intensity.Griffin(1994)concludeditisstatistically remains nearlyconstant.Datafrom thefourthseason,which Q 1985), Basrietal.(1989)werethefirsttoshowaspectrum give thecleanestphasecurve,are plottedinFig.20modulo about 0.03and0.08mag,while themaximumbrightness gives aperiodofapproximately 5.5daysineachoffour literature. may beamisprintoftheV=7.01repeatedelsewherein seasons. Theamplitudevaries from yeartoyear,between © American Astronomical Society • Provided by the NASA Astrophysics Data System While HD82443hasbeenincludedinseveralsurveysof Periodogram analysisofourphotometry ofHD82443 0.05 0.15 - 0 0.20.40.60.81.0 6.16 HD82443 Photometric Phase -1 1 _1 _1 -1 1 the rotationperiodofP=5.43±0.03determinedforthat responsible forthelightvariation. two spottedareasatdifferentlongitudesonHD82443are ticeable asymmetryofthisphasecurveimpliesthatatleast most astronomers.Therotationperiodof5.43daysandthe we obtainanaverageradialvelocityof8.25±0.07kms quennoy etal.(1991)andGriffin(1994).From11spectra season. Theamplitudeisapproximately0.06mag.no- leading toanapproximateinclinationof32°forthissingle agreement withthespectraltypepreviouslyassumedby and findusin/=5±1kms“.Fromavisualcomparisonof early-K dwarf. v siniof5kmsresultinaminimumradius0.54Æ, standards inthe6430Âregion,spectraltypeisKOV Latham etal.(1988)whofoundaperiodof3.39daysand The latteralsosuggestedaspectraltypeofK1orlaterforthe et al.(1983)hadpreviouslydeterminedasimilarorbitforit. circular orbitforthisshort-periodbinaryalthoughCarquillat unseen secondaryandestimatedaninclinationgreaterthan man 1985b)hasclassifiedthestarGO.Despitesolar-type cantly metalpoorwith[m/H]=-1.09.G.P.Kuiper(Bidel- 27°. AccordingtoLairdetal.(1988),thesystemissignifi- classification, spectraobtainedbyPasquinietal.(1991) of theirhigh-resolution,highsignal-to-noisespectrumHD filled inHaline.Spiteetal(1994)madeadetailedanalysis showed aCailKemissionfeatureofmodeststrengthand the mainsequence,withlogg=3.5,andfound[Fe/H] Laird etal.(1988).Spite(1994)alsoobtainedvsini 85091. Theyconcludedthestarissomewhatevolvedfrom rotation periodP=3.416±0.009,indicatingthatthesys- 0 tem issynchronouslyrotating.However,weseeasignificant and Carney&Latham(1987)haveobtainedphotometry range 2449766-2449805againstthe3.416dayrotationpe- searches formetal-poorstars,bothSandage&Kowal(1986) riod inFig.21,whereanamplitudeof0.03magcanbeseen. Consequently, weplotthedatainabbreviatedJulian-date amplitude onlyinthelastfewweeksofobservingseason. 85091. Periodogramanalysisofthesecondyeargives (s.e) (vanAltena1995)hasbeendetermined. (Table 2).Asmalltrigonometricparallaxof07016±0.011 broadening moredifficultanduncertain andresultinaprob- primary’s vsin/=7±1kms whilethesecondary’svsini = —0.52,avaluesignificantlymoremetalrichthanthatof bined withblendsandnoisemake determinationofitsline despite theprimary’smodestmassfunctionof0.014 Similar behavioroccurredinthefirstobservingseason. nary analysissuggestsamass ratio forB/Aof0.67.The = 9±3kmsfortheprimarystar.Aspartofextensive able overestimateofitsvalue. The minimumradiusofthe scopic binarywithalineratioforB/Aofabout0.1.Prelimi- (Latham etal.1988),thesystemisadouble-linedspectro- = 6±3kms”.Theveryweak linesofthesecondarycom- Our spectroscopicresultsareinaccordwiththoseofDu- Our attentionwasfocusedonHD85091bytheworkof Our surveyyieldedtwoyearsofphotometricdataforHD Our sixspectroscopicobservationsat6430Âshowthat, 6.17 HD85091 2945 1995AJ 110.2926H -1 > ponents. Averygoodfittotheprimaryisobtainedwithan < 2946 HENRYETAL:CHROMOSPHERICALLYACTIVESTARS primary is0.47R.Despitethelowvsinivalues,spectrum Fig. 21.LightcurveofHD85091plottedagainstphotometricphasecalcu- appropriately broadenedandweightedspectrumofHR4098 addition wasusedtodeterminethespectraltypesofcom- 0.03 mag. lated fromtheephemerisHID2449600.0+3.416E.TheamplitudeinVis 4098 andrCetresultsinareasonablefittotheveryweak reasonable agreementwiththoseofSpiteetal.(1994)and with appropriatelybroadenedandweightedspectraofHR spectral typeisrCet(G8V),whichhasamean[Fe/H] (F9 V),whichhasavalueof[Fe/H]=-0.48±0.21(Taylor published photometryofit. confirm thattheironabundanceismuchclosertosolar compare withHD85091.Nevertheless,ourresultsarein lines ofthesecondary,althoughaslightlylatertypeislikely. from assmall0.04magto largeas0.15mag.Gradual from thelasttwo-thirdsofthirdseason,whenlight be abinaryG5IVstarwithvsin/=15kmsandmoder- tables ofCCABSII.Fekel&Balachandran(1994)founditto of thissystem. observations arecontinuingandwillimprovetheparameters value thanthatfoundbyLairdetal.(1988).Spectroscopic KO: V.Unfortunately,wehavenometal-poorsubgiantsto Thus, weclassifythecomponentsofHD85091F9Vand throughout thetimespanof observations. increases anddecreasesinmean brightnessalsoareseen tional modulationvariesover our fourobservingseasons curve wasmostcoherent,areplottedinFig.22.Periodogram ate lithiumabundance.AsTable2shows,wecouldfindno 72146. Itisidentifiedasasingle-linedbinaryinthemain approximately 0.10mag.However, theamplitudeofrota- analysis ofthosedataresultsinarotationperiodP=21.5 spectrum showsemissionnearlyasstrongthatofHD (1991) foundCanHandKemission.Strassmeier’s(1994) 1994). Ouronlymoderatelymetal-poordwarfwithalater = -0.38±0.04(Taylor1994).Spectrum-additionanalysis 0 ±0.3 days.Therangeinbrightness duringthisintervalis © American Astronomical Society • Provided by the NASA Astrophysics Data System We havefourseasonsofphotometryforHD89546.Data HD 89546isanotherofthestarsforwhichBidelman 1.18 1.16 1.14 0 0.20.40.60.81.0 6.18 HD89546 Photometric Phase =-1 period of21.3daysandacircularorbit,resultsthatarecon- Fig. 22.LightcurveofHD89546plottedagainstJuliandate.Thephoto- giant andstandardswereappropriatelybroadened we confirmtherotationalbroadeningfoundbyFekel&Bal- firmed byourdata.Thus,thesystemisbothsynchronized and circularized.Frommeasurementsofadditionalspectra wavelength observations.Dadonas(1993)reportedanorbital metric periodis21.5days,andtheamplitudeinV0.10mag. broadened spectrumofßAql(G8IV)ratherthantheG5IV compared withHD89546.Neitherthecriticallineratiosnor achandran (1994):vsini15±2kms.Anumberofsub- minimum radiusof6.4Rqresultsfromtherotationalbroad- blueshifted emissionfeaturerisesabovethecontinuum.A though thecriticallineratiosappeartobeaboutright,some type assignedtoitbyFekel&Balachandran(1994).Al- the linestrengthsofG5—K2giantsfitspectrumHD AB, eachcomponentofwhichisnowknowntoconsista have emphasizedtheuniquenessofthislate-type“Vega- luminosity classIII-IVmightbemoreappropriate. ening andphotometricperiod.Sucharadiusindicatesthat absorption lineissignificantlyfilledwithemissionand of thestronglinesinstandardaretooweak.TheHa mains thesubjectofconjecture.Gregorio-Hetemetal. tem orwhetherthevisualbinaryisachanceprojectionre- components makeupagravitationallyboundphysicalsys- excess” systemfirstidentifiedbyWalker&Wolstencroft variable. Ithasnoabsorptionwingsandinonespectruma 89546. Instead,thebestfittoitsspectrumisanappropriately Bopp (1993b)orK4Vaccording toHouk&Smith-Moore is K5VaccordingtobothUpgren etal(1972)andFekel& tions Fekel&Bopp(1993b)concluded thatthesystemisin From ananalysisofhigh-dispersionspectroscopicobserva- age of10millionyearsorless. Thecompositespectraltype a pre-main-sequenceevolutionary stageandsuggestedan spectroscopic binary(Torresetal.1995).Whetherthevisual (1988). Thestarisactuallyaclosevisualbinary,ADS8191 (1992) firstfoundthestronglithiumlineofthissystem. (1988). Recently,Soderblom et al(1995)haveobtained Only onecomponentofHD89546isdetectedinourred- Skinner etal.(1992)andZuckerman&Becklin(1993) 9350 940094509500 Julian Date(2,440,000+) 6.19 HD98800 2946 1995AJ 110.2926H _1 -1 2947 HENRYETAL.:CHROMOSPHERICALLYACTIVESTARS Fig. 23.LightcurveofHD98800plottedagainstphotometricphasecalcu- 0.03 mag. lated fromtheephemerisHID2449600.0+14.8E.TheamplitudeinVis ported byHenry&Hall(1994).WeincludeHD98800in < Bopp (1993a),resultedinthediscoveryofvariabilityre- tem. Ourphotometryofthisunusualinfrared-excessstar,to period of14.7daysandinterpretedthisasaresultrota- this paperbecauseourphotometryhascontinuedbeyondthat search fortheBYDra-typevariabilitypredictedbyFekel& a result,havereevaluatedtheevolutionarystatusofsys- spectrograms thatresolvetheindividualcomponentsand,as which ledtotheinitialdiscoveryofvariability.Henry&Hall tional modulationoflightfromtheprimarystar,itssurface in Table2therangeof0.24magVisconsiderablygreater darkened unevenlybyafewlargespots.Itisinterestingthat (1994) foundarangeof0.07maginVwithphotometric than the0.07magrangeHenry&Hall(1994)hadfound photometry ofitincludesbothcomponentstheclosevi- has notyetbeenassignedavariablestardesignation. with theirdifferentialphotometry.Nevertheless,HD98800 to therotationperiodfoundbyHenry&Hall(1994)from first season’sdata.Thethirdseasonisplottedversusthe14.8 by Fekel&Bopp(1993b).AccordingtotheorbitsofTorres cycle variationinspotcoverage. about 0.035mag,halftheamplitudeobservedinfirst day periodinFig.23andisseentohaveanamplitudeof season givesP=14.8±0.2days,identicalwithintheerrors sual binaryADS8141AB.Periodogramanalysisofthethird et al(1995)thoseobservationsoccurredatphase0.4inthe season. Scatterinthephaseplotsuggestssomecycle-to- day orbitforcomponentBaandBfr.Ineachcasethephases 262 dayorbitforcomponenthaandatphase0.25inthe315 eccentric, withhahavinge=0.48andBaB& are computedfromperiastronsincebothorbitsrather The singlebroadenedfeatures of ourspectra,whichhave three starshappenedtobewithin 15kmsofeachother. v sin/=11kms,actuallyconsist ofthelinesallthree well separatedandinourobservations thevelocitiesofall e =0.78.Thelinesofthevariouscomponentsarenotoften stars. WenoteforaK5Vstar aradiusof0.7Rq(Gray 1992), combinedwiththerotation periodof14.7days © American Astronomical Society • Provided by the NASA Astrophysics Data System We havenowobservedHD98800forthreeseasons;our Our spectroscopicobservationsofthisstarwerediscussed 1.12 1.16 0 0.20.40.60.81.0 Photometric Phase -1 _1 _1 -1 -1 Fig. 24.LightcurveofHD99267plottedagainstphotometricphasecalcu- tudes areinthesenseHD99267minus96778.TheamplitudeVis lated fromtheephemerisHJD2449200.0+0.575£.Differentialmagni- 0.03 mag.Thecauseofvariabilityinthisstarisunknown. would clearlyidentifyHD98800asapre-main-sequence kms. Anyevidenceofsignificantrotationalbroadening the primaryof1.45Æ>twicecanonicalvalueforsucha main-sequence star. system. Forexample,ausin/of5kmsgivesaradiusfor (Henry &Hall1994),resultsinarotationalvelocityof2.4 were publishedbyYoung(1939).Fromfiveradialvelocities observed attheDavidDunlapObservatorywhosevelocities and italsoturnedouttobevariable.Itwasoneof500stars he concludeditsvelocitywasprobablyvariableandhada mean of-4.8±4.2(p.e.)kms.However,hecautionedthat A8 wasalsoestimatedfromthosespectrograms. its manylinesweredifficulttomeasure.Aspectralclassof in Fig.24.Asine-curvefittothedatagaveafullamplitude data fromthefirstseasonwith0.575dayperiodisshown ond seasonsallgavethesameresults.AphaseplotofV odogram analysesoftheBandVdataforfirstsec- at 1.354±0.001and3.282±0.002days.Separateperi- P =0.575±0.001dayswithsomewhatweakerpossibilities of HD99267minus96778forthefirstseasongives 0 binary (e.g.,Mantegazza&Poretti1995),twored- of 0.030±0.006mag.Thesameamplitudewasfoundinthe might betheresultofellipticityeffectinashortperiod other datasets. wavelength spectraofthisstarwereobtained4hraparton match thespectrumofHD99267. Averygoodfitwasfound from A9toF5wererotationally broadenedinanattemptto out apossibleshort-periodbinary.Ourmeanvelocityisrea- of 2.2kms~\differbyonly1.2s,andappeartorule with HR6844(FlV;Gray& Garrison1989)andsowe tively broadlineshavingvsin / =93±4kms.Standards expected fromYoung’s(1939) comment abouttheappear- ance ofthelines,ourredspectrum ofHD99267showsrela- sonably consistentwiththatofYoung(1939).Asmightbe 1995 April28.Thetworadialvelocitiesresultinanaverage We usedHD99267asthecheckstarforBD+30°2130, Periodogram analysisofourphotometricVobservations To determinewhetherthelightvariationsofHD99267 ^ -0.22 > -0.28 -0.24 -0.26 -0.20 -0.18 0 0.20.40.60.81.0 6.20 HD99267 Photometric Phase 2947 1995AJ 110.2926H 2948 HENRYETAL:CHROMOSPHERICALLYACTIVESTARS but growinggroupofearly-Fmain-sequencestarswith Fig. 25.LightcurveofHD112859plottedagainstJuliandate.Thephoto- metric periodis18.5days,andtheamplitudeinV0.08mag. binary system. member ofthegroup,HD96008.Theydemonstratedthatits has beensolvedbyMantegazza&Poretti(1995)forone obviously spotmodulationorÆScutipulsation.Thepuzzle of FlVthemechanismforvariabilityinHD99267isnot short-period, low-amplitudevariability(Krisciunasetal tion, theminimumradiuswouldbe1.06Rq. assign itthatclassification.Iftheperiodresultsfromrota- North GalacticPole,Schild(1973)obtainedJohnsonpho- variability istheresultofellipticityeffectinaclose the spectraltypeindicatedbymetalandhydrogenlines. tometry (Table2)andclassifiedthestarG8III-IV/?.Its two decadesago,aspartofhissurveyG-Kgiantsatthe rary dissipationofspotsonthe darkerhemisphere. two maximaandminimaforeachrotationcycle.Thus, Fig. 25.PeriodogramanalysisofthosedatagivesP=18.5 Because ofourdetectiondoublelines,itwasaddedto for atimetoonly0.02magbeforeincreasingagain.During HD 112859hasspottedareasattwowidelyseparatedlongi- ing seasons.Thelasthalfofthesecondseasonisplottedin spectrum waspeculiarbecauseitsGbandtooweakfor Strassmeier (1994)confirmedthestrongCaemission.Over from ourspectroscopicobservations. Atredwavelengthsthe while themaximumbrightness remained roughlythesame, the timeoflowamplitude,minimum brightnessincreased tudes. Inthethirdobservingseason,lightcurvedisplays a singlemaximumandminimum,theamplitudeshrinks (1991) detectionofitsCaliHandKemission.Recently, 1995) forwhichthecauseisunknown.Withaspectraltype 1993; Mantegazzaetal1994;Hall1995;Rodriguez&Zerbi suggesting thatthelowamplitude resultedfromthetempo- CCABS II. ±0.4 dayswithanamplitudeof0.08mag.Figure25reveals HD 99267appearstohavepropertiessimilarasmall © American Astronomical Society • Provided by the NASA Astrophysics Data System We observedHD112859photometricallyforfourobserv- Our interestinHD112859resultedfromBidelman’s The preliminaryinformationgiven inCCABSIIcomes 1.95 9100 912091409160 Julian Date(2,440,000+) 6.21 HD112859 -1 _1 -1 -1 -1 1 -1 we estimatearotationalbroadeningof^6kms.From km sfortheK0III.Avsinivaluefromweakand bined spectrum.Weconfirmthepreliminaryvsin¿=17±2 tical toourindependentsolution.Thus,thesystemislikely velocities oftheprimarystarDadonas(1993)hasdetermined often blendedlinesoftheFstarisdifficulttodeterminebut late-F startoreproducethestrengthofitslinesincom- minimum radiusoftheKgiantis6.2Rq. circularized andtheK-giantprimaryissynchronized.The different linestrengths.Theprimaryiswellfittedbythe greater than20days,andpossiblyhasaloworbitalinclina- cluded thatitprobablyhasalongorbitalperiod,certainly a periodof18.7daysandnearlycircularorbit,resultsiden- Finally, Buckleyetal(1987)estimateditsvsinias30 tometry fromwhichtheyclassifiedthestarasK2III-IV. tion. TheyalsoobtainedV=8.27,£-V=1.15,V-R emission andlow-amplitudevelocityvariations.Theycon- counterpart ofanHEAD1hardx-raysource.Theirspectro- spectrum ofßGem(K0III)whilethesecondaryrequiresa spectrum isdoublelinedbutthecomponentshavevastly km s.Beingaknownchromosphericallyactivebinary,it mined anorbitalperiodof23.7days,asemiamplitude6.7 scopic observationsshowedthatithasstrongCailHandK photometric amplitudeis0.04mag.Long-termbrightness period wasP=23.5±0.2days,makingthestarasynchro- formed theperiodogramanalysisonthosedata.Theresulting the variableminuscheckstardifferentialmagnitudesfor long-term brightnessvariationsofabout0.02mag,weused lines, theBalmerHelineofHD113816isinemission. CVn binaries.Theyobtainedasignificantlylowervsiniof km s,andanessentiallycircularorbit.Randichetal. of theconclusionsBuckleyetal.(1987)andhasdeter- was includedinCCABSII.Dadonas(1993)confirmedsome nous rotator.ThephasecurveisplottedinFig.26wherethe analysis ofHD113816.Thelasttwo-thirdsthefifthsea- addition totheextremelystrongCallHandKemission son displayedthemostcoherentlightvariation,soweper- [Fe/H]=—0.9. Recently,Strassmeier(1994)showedthat,in km s,amuchsmallervalue than theestimateofBuckley about 0.1mag. variations inHD113816arealsoseenwithanamplitudeof (1994) observedthesystemaspartofalithiumsurveyRS variations ofHD113449,itisnotincludedinTable3.We = 0.93,andV—/=1.57(seeTable2)aswellDDOpho- et al.(1994).Anexaminationof criticallineratioscompared et al.(1987)andevensmaller thanthevalueofRandich those ofDadonas(1993).We determinedusin/=5±l a single-linedbinarywithorbital elementsquitesimilarto did obtainonespectrumofitfromwhichwedeterminea spectral typeofKOVandvsin/=5±1kms“. 113816. Becausethecomparisonstar,HD113449,exhibited 10 kmsandclaimedthestarisquitemetalpoor,with Buckley etal.(1987)identifiedHD113816astheoptical We haveobtainedsixseasonsofphotometricdataforHD From ourspectroscopytodate, we findHD113816tobe Since wecouldnotfindanyperiodicityfortheobserved 6.22 HD113816 2948 1995AJ 110.2926H a -1 2949 HENRYETAL:CHROMOSPHERICALLYACTIVESTARS Fig. 26.LightcurveofHD113816plottedagainstphotometricphasecal- tudes areinthesenseHD113816minus111998.TheamplitudeVis culated fromtheephemerisHID2449400.0+23.5E.Differentialmagni- trum ofHR1907(KOIIIHwhichhas[Fe/H]=-0.58±0.06 indicate thatthestarismetalpoor,acomparisonwithspec- 0.04 mag. with starsofsolarabundancesindicatesthatHD113816has rather lowprojectedrotationalvelocitysuggestsarota- The combinationofverystrongchromosphericactivityand a spectraltypeofaboutK0III.Whilethelinestrengthsdo somewhat stronger.Unfortunately,wedonothaveanexten- tional inclination.Thevsiniandphotometricperiodresult sive gridofmetal-poorgiantsforadditionalcomparisons. (Taylor 1991),showsthatmostlinesofHD113816are with alowrotationalinclination.Forexample,anassumed in aminimumradiusof2.3jR>valuelikewiseconsistent radius of12R©resultsinaninclination11°. > < bandpass photometry,heconcludedthatthestarisagiant photometric variabilityoftheRSCYnvariety.Forsame period isquiteshortforagiantstarand,thus,shouldshow program becauseGriffin(1988a)hadnotedthatthe59day may beastarofearlierspectraltype.Wehaditonour with aspectralclassbetweenK0andK1whileitssecondary an eccentricityof0.59.Fromadiscussionexistingmulti- reason itwasacandidateinCCABSII,awaitingonlythe single-lined binarywithanorbitalperiodof59.054daysand then, Strassmeier(1994)hasobservedCallHandKemis- detection ofmanifestationschromosphericactivity.Since sion lineswellabovethenearbycontinuum,confirming 0 vey isplottedinFig.27.Periodogramanalysisofthosedata suspected chromosphericactivity,andStrassmeieretal. time was0.20mag.Duringthe firstobservingseason,HD lation ofitsbrightness!Atthattime themeanbrightnesswas during thesecondobservingseason. Theamplitudeatthat HD 118234hadlargespottedareas onoppositehemispheres two maximaandminimaperrotation cycle,indicatingthat gives P=64±1dayfortherotationperiod.Figure27shows (1994) havedeterminedvsin/=4:kms. 118234 wasnearlyconstant,with almostnorotationalmodu- © American Astronomical Society • Provided by the NASA Astrophysics Data System Griffin (1988a)foundthismoderatelybrightstartobea The secondofthreeseasonsphotometryfromoursur- 6.23 HD118234 -1 Fig. 27.LightcurveofHD118234plottedagainstJuliandate.Thephoto- metric periodis64days,andtheamplitudeinV0.20mag. more uniformlyinlongitudeduringthefirstseason.HD the firstandsecondseasonsbutwithspotsdistributedmuch essentially equaltothemeanbrightnessforsecondsea- the firsttwoobservingseasons. son. Thissuggeststhatthetotalspottedareawassamefor have acompositespectrumconsistingofKgiantandan early-F star,wecarefullyexaminedourlonered-wavelength son, withameanbrightnessabout0.03magbrighterthanin wavelength regionisnotoptimalforthedetectionofahotter companion, suchcompanionshavebeendetectedforseveral spectroscopic observationofthissystem.Althoughthat of thestarsinoursurvey.Fromavisualexamination 118234 hadanintermediateamplitudeduringthethirdsea- broadened andoverplottedonourspectrum,whichwasob- From thiscomparisonweconcludethatthereisnoevidence tained closetomaximumvelocityseparationatphase0.074. /3Gem (KOIII)andeCrB(K2soweclassifyHD standards. Thebestfitappearstobeintermediatebetween spectrum thecriticallineratiosdonotquitefitanyof photoelectric-velocity dipwidthsdonotsuggestunusually value consistentwithGriffin’s(1988a)statementthathis of asecondstar.Wedeterminevsin/=5.5±1.0kms, this red-wavelengthregionareweakenedbythecontinuum of anylinesasecondstarnorthattheprimary’sin period, theresultingminimumradiusis7.0Rq,quitecon- rapid rotationandStrassmeieretal.’s(1994)somewhatun- certain value.Whenourvsiniiscombinedwiththerotation ric rotationperiodandtheorbitalaresimilar,orbit is quiteeccentric,e=0.59,resultinginapseudosynchro- nous rotationperiodof15.1days.Thus,the sistent withthegiantclassification.Althoughourphotomet- Latham etal.(1988)whofound ittobeasingle-linedbinary 118234 K1III.Thosetwostandardswereappropriately et al.(1988)obtained[m/H]= —0.43, suggestingamodest with aperiodof14.50daysand an eccentricityof0.48.Laird of HD118234isfourtimesgreaterthanpseudosynchronous. Because Griffin(1988a)suggestedthatHD118234might Our interestinHD118981stems fromtheworkof 6.24 HD118981 2949 1995AJ 110.2926H -1 _1 > < 2950 HENRYETAL:CHROMOSPHERICALLYACTIVESTARS culated fromtheephemerisHJD2449600.0+5.94£.TheamplitudeinVij95days,andBis0.03mag. Fig. 28.LightcurveofHD118981plottedagainstphotometricphasecal-29.122767Juliandate.Thephoto- metal deficiency.Aspartofextensivesurveysformetal-poor is only0.01mag. Those dataareplottedinthephasecurveofFig.28.Asine- are toosparsetoconsider.Periodogramanalysisofthethird are availablefromoursurvey,thedatafirstseason both thesecondandthirdseasonsallgivesimilarresults.(3) result forseveralreasons.(1)Theamplitudefoundinthe mag. Whilethephasecurvelooksrathernoisybecause curve fittothosedatagivesafullamplitudeof0.009±0.002 season resultsinarotationperiodP=5.94±0.04days. (1987) haveobtainedphotometry(Table2). stars, bothSandage&Kowal(1986)andCarneyLatham primary’s lineswithspectraofHR4098(F9V),having[Fe/ lines withalineratioforB/Aofabout0.1.Fromtheabun- tral type. consistent withtheradiusassumedfromprimary’sspec- eccentric binarysystem.(5)Thederivedminimumradiusis A 5.94dayperiodisnotfoundinthecheckminuscompari- error. (2)ThesecondobservingseasonandtheBdatafor least-squares sinefitissignificantlylargerthantheformal amplitude isquitesmall,webelieveintherealityofthis dance analysisofLairdetal(1988)weanticipatedthatthe day periodpredictedforpseudosynchronousrotationinthis those ofthemetal-poorstandards.Instead,bestfitto diluted linesoftheprimaryweresignificantlystrongerthan ing [Fe/H]=-0.43±0.05(Taylor1994).Inbothcasesthe H]=—0.48±0.21 (Taylor1994),andHR5914(F8V),hav- ing isactuallyless thantheprimary’sbutformer’s lines latter classificationisperhapsseveral subclassesbecausethe and weightedcombinationsofspectrathathaveessentially son data.(4)The5.94dayperiodfoundisveryclosethe5.53 solar abundances.Arepresentativebestfitwaswith10Tau stars wouldbesomewhatmetalweakandsocomparedthe secondary’s linesaresoweak. The primaryhasvsini=7 sify thecomponentsF9Vand KO V.Theuncertaintyofthe spectrum ofHD118981waswithappropriatelybroadened (F9 IV-V)and12OphA(KOV;Wilson1962),soweclas- metrc per0£s ±4 kms.Presumably,thesecondary’s rotationalbroaden- ± 1kmswhiletheweaksecondary linesgivevsini=7 © American Astronomical Society • Provided by the NASA Astrophysics Data System Although photometricdatafromthreeobservingseasons Our spectraofHD118981showveryweaksecondary 0.26 0.25 0.27 0 0.20.40.60.81.0 Photometric Phase -1 radius of0.7R.Thepseudosynchronousrotationperiodis bined withthevsiniofprimaryresultsinaminimum that thedifferencecouldresultfromdifferentialrotationin their errorsdonotformallyoverlap.Nevertheless,webelieve 5.53 ±0.13dayscomparedwithourphotometricperiodof estimated uncertainty.Theobservedrotationperiodcom- rotating. 5.94±0.04 days.Althoughquitesimilar,thetwoperiodsand are broadenedbyblendsandnoise,resultinginourlarge Despite anobservedrangeof0.25maginV,theywereun- back toFekel&Hall(1985),whobecameinterestedinitas type ofK3III(Heard1956).Wehavecontinuedtoobserve such astarandconcludethattheispseudosynchronously plitude inVwasonlyabout0.01mag.Similarperiodsand Fig. 29.PeriodogramanalysisgivesP=96±ldays.The fourth season’sdataplottedagainstJuliandateareshownin Can HandKemissionwithsharpcentralreversals, a hugeeccentricityof0.871.Strassmeier(1994)foundweak able todetermineaperiod.Griffin(1988b)showeditbe variability, hadconcludedonlythatitwaspossiblyvariable. this starbecauseHooten&Hall(1990),intheirsearchfor a resultofitsvelocityvariability(Heard1956)andspectral ported previouslybyHooten& Hall(1990).Theorbitalele- but definitelyperiodicvariationreportedhereisincontrastto the amplitudeinBisconsiderablygreaterthanV.The Strassmeier etal.(1994)determinedvsini=4kms. single-lined binarywithanorbitalperiodof1189.2daysand tation period(Hut1981)thatis abouttwiceasfastthe ments ofGriffin(1988b)result inapseudosynchronousro- the 0.25magrangeandlackofanidentifiableperiodre- amplitudes areseenintheotherseasons.Thelowamplitude obtained. Visualexaminationof thisred-wavelengthspec- observed period,49vs96days. amplitude inBwasapproximately0.03magwhiletheam- Q PQ 122767. WechosetoanalyzetheBdataforthisstarbecause < Our suspicionofthelightvariabilityHD122767dates We nowhavefiveseasonsofphotometricdataforHD One spectroscopicobservation of HD122767hasbeen 9350 9400945095009550 Julian Date(2,440,000+) 6.25 HD122767 2950 1995AJ 110.2926H _1 2951 HENRYETAL.:CHROMOSPHERICALLYACTIVESTARS Fig. 30.LightcurveofHD131511plottedagainstJuliandate.Thephoto- metric periodis10.39days,andtheamplitudeinV0.04mag. modest butsignificantrotationalbroadeningof8±1kms, the classificationgiveninHeard(1956).Thelineshavea trum indicatesaspectraltypebetweenthatofeCrB(K2III) Our vsiniandrotationperiodresultinaminimumradiusof and ßCnc(K4III)soweclassifyitK3IIIinagreementwith somewhat largerthanthatfoundbyStrassmeieretal(1994). containing aK-typedwarfwithemissionofmoderate peared inCCABSII.Theabsenceofestablishedphotometric variability, evidencedbyablankinTable2ofthatcatalog, strength intheCaIIHandKlines;forthosereasonsitap- was responsibleforitbeingonourobservingprogram.Two 15.2 Rq,quiteconsistentwithitsspectraltype. <1 > tent witheachother:Kamper&Lyons(1981)found independent spectroscopicorbitsresultedinelementsconsis- of Keenan&McNeil(1989),themanyotherpublishedclas- the oldG8ofG.P.Kuiper(Bidelman1985b)andK0.5V P= 125.374daysand < -0.28 -0.29 -0.30 0 0.20.40.60.81.0 Photometric Phase -1 photometry. Themeanrotationperiodandourvsiniresult in aminimumradiusof1.5Æ>indicatingthattheprimary, culated fromtheephemerisHID2449400.0+1.65IE.TheamplitudeinV Fig. 32.LightcurveofHD144110plottedagainstphotometricphasecal- component Aa,isindeedsomewhatevolved. with thosethatGriffin&Duquennoy(1993)derivedfrom is 0.05mag. J1601+512 andlisteditasaG5star.Surveyingsomeofthe counterpart totheextremeultravioletROSATsourceRE bined withourspectroscopicresults.Aftermakingthisas- Bopp (1994)obtainedseveralred-wavelengthspectraofit period. Thus,thesystemissynchronouslyrotating,asex- problems andtheygavenodetailsoftheiranalysis,if have acircularorbitandanorbitalperiodof1.671days. who independentlydiscovereditsduplicityandfounditto the mostreasonableminimumradiusforstarwhencom- P =1.651daysastherotationperiodbecauseitalsogives Periodogram analysisofthefirstseasongivesP=1.651 filled inbyemission. cluded thatboththeHaandCaH8542Âlineswerepartially and discoveredittobeadouble-linedbinary.Theycon- late-type starsintheROSATEUVsourcelist,Mulliss& plitude isapproximately0.05mag,butconsiderablescatter pected forsuchashort-periodsystem.Thefirstseason’sdata While theirobservationsmaybesubjecttothesamealiasing P =0.622±0.001and2.525±0.007days.Weadopt orbital periodisright,wehaveidentifiedthecorrectrotation sumption, wediscoveredtheworkofJeffriesetal.(1994), tively, fortheprimaryandsecondary. Thebestfittothe of 0.67.Thevsin/’sare26±2 and22±2kms,respec- double lineshavinganestimated line-strengthratioforB/A first andsecondobservingseasons. amplitudes arefoundintheotherVandBdatasets.The occurs aroundthelight-curveminimum.Similarperiodsand are phasedagainstthisperiodinFig.32.Therotationalam- system hasundergonea0.03mag brighteningbetweenthe ±0.003 days,butslightlyweakerperiodsarealsofoundat 0 Pounds etal.(1993)identifiedHD144110astheoptical We havetwoseasonsofphotometricdataforHD144110. Our red-wavelengthspectroscopic observationsshow 0.76 0.72 0.78 0.74 0.80 0 0.20.40.60.81.0 6.28 HD144110 Photometric Phase 2952 1995AJ 110.2926H 1 2953 HENRYETAL.:CHROMOSPHERICALLYACTIVESTARS culated fromtheephemerisHID2449300.0+13.80E.Differentialmag- Fig. 33.LightcurveofHD148127plottedagainstphotometricphasecal- mum radiusof1.3Rqfortheprimary.Fromourvsiniand rules outthe2.5dayperiod,whichwouldresultinamini- classify thestarsG8VandKlV.Thedwarfclassification though thesecondaryappearstobeslightlylater.Thus,we weighted spectraof61UMa(G8V)andcrDra(KOal- is 0.05mag. nitudes areinthesenseHD148127minus148554.TheamplitudeV 0.85 Rq. a rotationperiodof1.651daystheminimumradiusis spectrum ofHD144110iswithappropriatelybroadenedand parison starforHD148405andprovingtobevariableas period. Anamplitudeof0.05magisobserved,probablythe well. Remarkablylittleisknownaboutthisreasonablybright largest ofthefourseasons. data forHD148127minus148554resultsinP=13.80 km s".Whileourlimitedresultsareconsistentwithacon- months, whichhaveanaveragevelocityof—16.3±0.2 term velocityvariations.Avisualexaminationofitsspectra star. ThespectraltypeisK5accordingtotheHDcatalog. scopic observationsofHD148127overanintervaltwo While thisminimumradiusindicates thattherotationalin- rotational velocityproducesaminimumradiusof1.1Rq. rotation, thecombinationofthatperiodandprojected same type.Itslinesareslightlybroadenedwithvsini=4 shows itisquitesimilartoßCnc(K4III)soweassignthe stant velocity,wehavenoknowledgeaboutpossiblelong- giants, discussedinSec.5,whose rathershort-periodvari- low inclinations.HD148127is one ofthetwosingleK-type ability weattributewithsomehesitation tospotmodulation. that rotationalvariabilitycanbe detectedongiantswithvery clination isquitelow,ourresults forHD113816demonstrate ±0.06. ThosedataareplottedinFig.33,phasedwiththis ±1 kms+ © American Astronomical Society • Provided by the NASA Astrophysics Data System This starappearsinourpaperbyvirtueofbeingthecom- Periodogram analysisofourfourthseasonphotometric In the6430Âregionwehaveobtainedthreespectro- If weassumethatourphotometricperiodistheresultof 6.29 HD148127 Julian Date Photometric Phase(2,440,000+) 0 gj93509400945095009550 4 0 -1 _1 because Hooten&Hall(1990),intheirsearchforvariability, period is56.9days,andtheamplitudeinV0.04mag. magnitudes areinthesenseHD148405minus148554.Thephotometric Fig. 34.LightcurveofHD148405plottedagainstJuliandate.Differential Fekel &Hall(1985).Thisstarremainedonourprogram had concludedthatitwaspossiblyvariable.Theonlypub- by Oja(1984)aspartofaprojecttoobservestarswithac- HD Catalog,whileGriffin(1982)hasarguedthatitislikely lished spectralclassificationwecouldfindistheK0in with anorbitalperiodof52.453daysandaverysmallec- to beagiant.Healsoshoweditsingle-linedbinary curately knownpositions.ItwasacandidateinCCABS//, centricity of0.021.UBVphotometry(Table2)wasobtained awaiting onlydetectionofmanifestationschromospheric very asymmetric,emissionlinesthatmightindicateanactive activity. Subsequently,Strassmeier(1994)didfindweak,and chromosphere. Finally,Dempseyetal.(1993)reportedanull to thecheckstar.ThelightcurveoffourthseasonforHD detection ofx-rayemission,andStrassmeieretal.(1994) period of52.453daysgivenbyGriffin(1982),indicatingthat determined vsin¿=4kms. mately 0.04magthelargestforfourobservingseasons. the starissynchronouslyrotating.Theamplitudeapproxi- for therotationperiod,whichisquiteclosetoorbital able, weanalyzedthelightvariationsofHD148405relative 34. PeriodogramanalysisofthosedatagivesP=56.9±0.8 comparison withvariousstandardspectraindicatesaspectral violet ROSATsourceREJ1738+611 (Poundsetal.1993), type betweenoUMA(G5III;W.MorganinStebbins& shows modestrotationalbroadeningof7±1kms.Avisual G6 III.Itsminimumradiusfrom itsrotationperiodand Kron 1956)andkGem(G8III).Thus,weclassifyitasa v siniis7.9Rq. 148127, havebeendiscoveredtobephotometricallyvari- 148405. SinceHD148405anditscomparisonstar, 148405, inthesensevariableminuscheck,isshownFig. Our suspicionofphotometricvariabilitydatesbackto We havefiveseasonsofphotometriccoverageforHD Our onered-wavelengthspectrumobtainedforthisstar This staristheopticalcounterpart totheextremeultra- 6.30 HD148405 6.31 HD160934 2953 1995AJ 110.2926H -1 _1 resulted inthedetectionofastrongHaemissionfeature. Periodogram analysisofthefirstseasongivesP=1.842 HD 160934aspartofasurveydwarfKandMstars. Weis (1993)recentlyobtainedUBVmagnitudes(Table2)of whose spectraltype,followingVyssotsky(1956),theylisted culated fromtheephemerisHID2449400.0+1.842E.TheamplitudeinV Fig. 35.LightcurveofHD160934plottedagainstphotometricphasecal- 2954 HENRYETAL:CHROMOSPHERICALLYACTIVESTARS as K8V.Follow-upspectroscopybyMulliss&Bopp(1994) is only0.02mag. first occursatP=2.181±0.007days.Thesametwoperi- possibly apre-main-sequence star. Itsspectrumwascom- period similartothatfoundfromourphotometry.Although else reddeningofE(B—V)=0.2mag,butalate-Kdwarf ness ofthebrighterhemisphere. ods arealsoseeninthesecondseasonaswellB pared withappropriatelybroadened spectraof61CygA insignificantly reddened. mag andameanbrightnesslevelabout0.02abovethe riod. Therotationamplitudeisonlyabout0.02mag. ously decidewhichperiodrepresentsthetruerotation data frombothseasons.Atpresent,wecannotunambigu- broadening of13±1kmsindicate itislikelyaZAMSor noted byMulliss&Bopp(1994) anditssignificantrotational not ashort-periodbinary,thestrongchromosphericactivity clude thatthestarprobablyhasaconstantvelocity.Sinceitis tions overafour-nightperiod.Theaveragevelocityis—26.7 a dwarfwithanultravioletexcessofS(U—B)=0.2magor second seasonmustresultfromandecreaseinthespotted- about thesameforbothseasons,largeramplitudeof first season.Sincethelevelofminimumbrightnessremains and whichisanalias.Sincethe1.842dayperiodslightly indicate aspectraltypeofK7V. Ourchosenrotationperiod long-term velocityvariationscannotberuledout,wecon- ertheless, werecentlyobtainedthreespectroscopicobserva- second observingseasonshowsanamplitudeofabout0.04 stronger, weplotthephasecurveinFig.35againstthispe- (K5 V)and61CygB(K7V).The stronglinewingsclearly V= 10.3magshouldbeonlyabout30pcawayandhence ±0.005 days,butasecondperiodnearlyasstrongthe ±0.1 kms,whichexcludesanyvelocityvariationswitha © American Astronomical Society • Provided by the NASA Astrophysics Data System We havetwoseasonsofphotometricdataforHD160934. We notethattheU-BandB-Vindices(Table2)imply This starisoneofthefaintestonesonourprogram.Nev- 2.14 - 2.12 - 2.10 - 0 0.20.40.60.81.0 Photometric Phase 1 _1 J1834+184. Mulliss&Bopp(1994)obtainedspectrathat results inarotationalinclinationofapproximately50°. is 0.10mag. culated fromtheephemerisHJD2449400.0+1.33%E.TheamplitudeinV Fig. 36.LightcurveofHD171488plottedagainstphotometricphasecal- A strongaliasat3.942daysisalsoevidentintheperi- by emission.Theyalsoclaimedthatthelithiumlineofthis counterpart totheextremeultravioletROSATsourceRE and vsinivaluegiveaminimumradiusof0.5Rq,which curve withthisperiodisplottedinFig.36andshowsan which haveanaverageradialvelocityof—22.6±0.3kms“. dwarf luminosityclassification. odogram butwepreferthe1.338dayperiodbasedon have obtainedStrömgrenphotometryofit,withOlsen’s that ofthePleiades.Perry(1969)andOlsen(1983,1994) GO V(Harlan1969)starisquiteyoungwithanagelessthan Pleiades stars.Mulliss&Bopp(1994)concludedthatthis broad withvsin¿=33±2kms.Thelargeiandso- that shownbyMulliss&Bopp(1994).Thelinesarequite amplitude ofabout0.1magwithsomecycle-to-cyclescatter. P=1.338±0.002 daysfortherotationperiod.Thephase Ci =0.320. showed bothitsHaandCaII8542Âlinesarepartiallyfilled GOV toG5VfitthespectrumofHD171488reasonably lar typemakeclassificationdifficultbecausesmallline- core ofHaispartiallyfilledbyemission,aresultsimilarto Our soleobservationoftheHaregionshowsthatline star hasanequivalentwidththatis50%greaterthansimilar early-G dwarfsandsubgiantsin the6430Âregion,weclas- well. Sincethereislittledifferencebetweenthespectraof the classificationofHarlan(1969). Fromourvsinianda all additionalinformationindicates thatthestarisadwarf and soitislistedasG2:V:inTable 4.TheCjindexofOlsen sify thestarasG2:IV-Vfrom thespectraalone.However, strength differencesaresmearedout.Spectralstandardsfrom (1983) valuesbeingF=7.39,=0.394,and (1983) identifiesthestarasadwarf (Olsen1984),supporting > .• 171488. Periodogramanalysisofthefirstseasongives Pounds etal.(1993)identifiedHD171488astheoptical We obtainedfourred-wavelengthspectraofHD171488, We acquiredtwoseasonsofphotometricdataforHD 0.65 - 0.55 -.* 0.50 F 0 0.20.40.60.81.0 . • • 6.32 HD171488 Photometric Phase 2954 1995AJ 110.2926H -1 -1 -1 _1 2955 HENRYETAL:CHROMOSPHERICALLYACTIVESTARS Fig. 37.LightcurveofHD181475plottedagainstJuliandate.Thephoto- variability inthisstarislikelyduetopulsations. metric periodis31days,andtheamplitudeinV0.06mag.Thecauseof ened standards,yetanotherindicationoftheextensiveactiv- the linebottomsappeartobetooflatcomparedbroad- rotation periodof1.34days,theminimumradiusis0.87/?©• interesting starspotmap. ity ofthisstar.Thus,Dopplerimagingshouldproducean to thephotometricvariability,filledHa,andrapidrotation, for ourphotometryof26Aql=HD181391,whichisnow Such aradiusimpliesanindicationofabout60°.Inaddition known tolacksignificantchromosphericemission(Strass- meier etal.1993).ThetwoVmagvaluesinTable2differby 0.05 mag,butitisnotclearifthisshouldberegardedasan tively. Alow-resolutioninfraredspectrumwaspresentedby trophysical Observatory(Redman1938)andLickObserva- Paddock (1950),MOIIbyMorgan&Keenan(1973)and cations canbefoundintheliterature:K5IIbyMoore& early indicationofvariability.Threesimilarspectralclassifi- tory (Moore&Paddock1950)are1and3kms,respec- Keenan &McNeil(1989).VelocitiesfromtheDominionAs- Keenan &Pitts(1980),and,finally,arevisiontoK7liaby > HD 180086.Forapproximatelytwomonthsin1991, giant wasdiscussedbyJura&Kleinmann(1990). Olnon &Raimond(1986)andmasslossfromthisbright odogram analysisofthosedatagivesP=31±ldays,with cycles ofcoherentvariabilitywereseen(Fig.37).Peri- < this late-typehigh-luminositystaristheresultofpulsations. an amplitudeof0.06mag.Wepresumethatthevariabilityin The lineshaveatotalbroadening of8.4kms.Withan assumed macroturbulenceof8-6 kms(Gray&Toner trum isclearlylaterintypethan anyofourevolvedstandards with thepreviousresults.However,ifstarisindeedpul- Keenan’s K7liaclassification (Keenan &McNeil1989). (K5 IIIisthelatest)andthus,appears quiteconsistentwith sating itmayhavedetectablevelocity variations.Thespec- 181475. Ouraveragevelocityof4.3kmsisinagreement HD 181475wasoriginallychosenasthecomparisonstar © American Astronomical Society • Provided by the NASA Astrophysics Data System We analyzedthelightvariationsofHD181475relativeto We obtainedtwored-wavelengthobservationofHD 0.30 0.32 0.34 0.36 Julian Date(2,440,000+) 6.33 HD181475 _1- -1 -1 -1 _1 Fig. 38.LightcurveofHD202951plottedagainstJuliandate.Thephoto- km s,soweconcludethatvsin/=4±3. metric periodis21.6days,andtheamplitudeinV0.03mag. known aboutit.Young(1945)reportedfourvelocitiesob- confirm asvariable.Forsuchabrightstar,relativelylittleis the comparisonstarforHD202908,whichwecouldnot had arangeof9kms,greaterthanthatmanythe680 tained atDavidDunlapObservatory.Anapparentconstant velocity of—35.3kmswasfoundbutthemean of K6whiletheTheBrightStarCataloguelistsK5IIIbutits other starsinthesurvey.Young(1945)gaveaspectralclass HR 8149belongstotheso-calledHyadesMovingGroup.A giant classificationseemstorestonthegeneralbeliefthat 1986, 1987),therotationalvelocitywouldrangefrom2to6 negative resultintheirsearchforduplicityusingspeckle Raimond (1986)andMcAlisteretal(1987)obtaineda low-resolution infraredspectrumispresentedbyOlnon& coherent variability.Theresultingperiodwas21.6±0.5days, which wereanalyzedinthesenseHD202951minus interferometry. reported here,suggestingthatspotsonoppositehemispheres 203842. Wechosea60dayintervalofthefourthseason(Fig. radial velocities,themeanofwhichis—36.6kms.Sucha were dominatingtherotationalmodulation. and theamplitudewasapproximately0.03mag.Laterin 38) forperiodogramanalysisbecauseitdisplayedthemost blended lines.Ourrotationperiod andprojectedrotational found byYoung(1945),supportingtheviewthatitsvelocity value isinexcellentagreementwiththeaveragevelocity 202951 obtainedonconsecutivenightshavenearlyidentical same season,theperiodapparentlydecreasedtohalfthat velocity resultinaminimumradius of1.7Rq.Thisisthe of linecrowding,whichmakes itdifficulttofindweakun- is constant.ItsspectrumquitesimilartothatofHR4954 tally identicaltotheonein The BrightStarCatalogue (Hoffleit 1982).Itslinesareslightly broadened,withvsini (K5 III)andweassignitthesameclassification,coinciden- = 4±2kms.Therelativelylarge uncertaintyistheresult HD 202951appearsinourpaperbecausewechoseitas We havefiveseasonsofphotometricdataforHD202951, Two red-wavelengthspectroscopicobservationsofHD 6.34 HD202951=HR8149 Julian Date(2,440,000+) 2955 1995AJ 110.2926H -1 -1 -1 2956 HENRYETAL.:CHROMOSPHERICALLYACTIVESTARS Fig. 39.LightcurveofHD203387plottedagainstphotometricphasecal- is 0.03mag. culated fromtheephemerisHJD2448700.0+68.0E.TheamplitudeinV hesitation tospotmodulation. whose rathershort-periodvariabilityweattributewithsome of itssignificantCallHandKemission(Wilson1976). time ago(Fekel&Hall1985),Hooten(1990)could the emission.Whilewehadsuspecteditofvariabilitysome conclude onlythatitwaspossiblyvariable.Forthisbright Strassmeier (1994)displayedahigh-dispersionspectrumof second ofthetwosingleK-typegiants,discussedinSec.5, might bemoreaccuratethanG7orG8.Campbell&Moore have determinedarotationperiodof68±6daysfrommodu- rotation periodof90days.Veryrecently,Choietal.(1995) giant isrelativelynearby,havingatrigonometricparallaxof have concludedthestarhasaconstantvelocity.Thisyellow found intheliterature,althoughGray(1989)arguedG5.6 lation ofCailHandKemission.Thesignificantnumber the inclinationandradius,Strassmeier(1994)estimateda ing toGray(1989).Fromthevsiniandassumedvaluesfor cording toGray&Pallavicini(1989)or5.7kmsaccord- 0'.'031 (vanAltena1995).Itmeansvsiniis6.1kmsac- star numerousspectralclassificationsofG8IIIorG7are little dispersion,afullrangeoflessthan0.03mag. became operational.Periodogramanalysisoftheselastthree yr. Variabilityisunambiguouslydetectedonlyinthefinal (1928), Beavers&Bitter(1986),andYoungetal.(1987)all tion periodP=68.0±0.3days,inexcellentagreementwith observing seasons,takentogether,yieldsaphotometricrota- three observingseasonsafterthenewprecisionphotometer eral observers.Avisualcomparison withourspectraltype km s,consistentwiththeconstant velocityfoundbysev- tivity haspersistedatonelongitude. together sowellinFig.39indicates thatlong-livedspotac- of approximately0.03mag.Thatthreeyearsdataphase the valueChoietal.(1995)determinedfromcalciumemis- 68 dayrotationperiodinFig.39,wherewefindanamplitude sion variations.Thosethreeseasonsareplottedagainstthe V-magnitude determinationslistedinTable2showrelatively standards resultsinaclassification ofG6III,whichisin © American Astronomical Society • Provided by the NASA Astrophysics Data System The brightstarHD203387wasonourprogrambecause HD 203387hasbeenmonitoredbythe0.4mAPTfor7 The averageofourthreeradial velocitiesis12.3±0.2 -2.58 - -2.64 - 6.35 HD203387=HR8167=32lCap 0 0.20.40.60.81.0 Photometric Phase -1 -1 _1 prung gap,istheresultofadynamo-generatedmagnetic brake. Theverymodestchromosphericandspotactivityof with themostrecentvalueofGray(1989).(1989)has HD 203387areconsistentwiththeresultingrotationalveloc- argued thattherapiddeclineofsurfacerotationalvelocity, Gray (1989).TheHalineofHD203367appearstobea also consistentwiththeearlierspectraltypesuggestedby good agreementwithG7IIIofKeenan&McNeil(1989)and mum radiusof8.1R. ity decrease.Therotationperiodandvsin/resultinamini- seen insinglegiantstarsastheybegintocrosstheHertzs- sion. Ourvsin/of6±1kmsisinexcellentagreement bit (Abt&Levy1976),itwasaclearcaseofchromo- strong absorptionfeaturethatisfilledwithlittleornoemis- troscopic orbit,thatofAbt&Levy(1976),showsittobe firmed bythespectrumintheirFig.6.Themostrecentspec- emission (Young&Königes1977)andthespectroscopicor- described theHandKemissionasweak,astatementcon- spherically activebinaryand,thus,hasappearedinboth able forsometime(Hall1983).WiththeCallHandK As reportedinCCABSII,wefoundthatthesystemshows lier orbitsareallcitedinthecatalogofBattenetal.(1989). CCABS IandII.However,Femández-Figueroaetal(1994) nary vsin/=5.5kmsfortheprimaryinagreementwith single linedwithP=13.1740daysand£=0.18.Fourear- double linesatredwavelengthsanddeterminedaprelimi- evidence ofanywidelyseparatedcompanions.Roman a valueof5kmsaccordingtoHuisong&Xuefu(1987). plitude, obviousfromtheoutset,indicatedsmallandhence pected shortrotationperiodof11daysifitispseudosynchro- most difficulttoanalyze.TheG2spectraltypeandtheex- variable byatleast0.05maginV. taken atfacevalue,suggestsHD206301isaphotometric gives G2IV.ThefullrangeofmagnitudesinourTable2, a misprintsincetheyciteCCABSIasthesource,whichitself Gl V4-G0VintheFourthEditionofTheBrightStarCata- while Houk(Houk&Smith-Moore1988)foundG2Vfrom Speckle interferometrybyMcAlisteretal.(1987)foundno nous, pointtoaRossbynumbersmallenoughthatHD logue (Hoffleit1982).Randichetal.(1993,1994)listG2V, an objective-prismspectrum.Itisratherstrangelylistedas (1952) andKeenan&McNeil(1989)classifieditG2IV, resulting periodogramsshowed multipleperiodicities,clus- longest spanningonly106days.Toallowforthepossibility 0 between. Onlyinthevicinityof 12days,however,didperi- with acurvecontainingterms in bothsin6and26.The our 4.2yrofBandVphotometryintoeightdatasets,the 206301 shouldbeastarspotvariable.Thesmalloverallam- the Blightcurves.Weconclude thatthetruerotationperiod, odicities appearinalleightdata groupsandinboththeV tered around9,10.5,12,14,16, and17.5daysbutabsentin light variation,wedidtheperiodsearchbysuccessivefits of twospotsbeingpresentandproducingadouble-humped short-lived (Hall&Henry1994)starspots.Thus,wedivided HD 206301hasbeenofinteresttousasasuspectedvari- Our photometricdataforHD206301provedtobethe 6.36 HD206301=HR8283=42Cap 2956 1995AJ 110.2926H -1 _1 _1 2957 HENRYETAL.:CHROMOSPHERICALLYACTIVESTARS culated fromtheephemerisHID2449200.0+12.1£.TheamplitudeinV Fig. 40.LightcurveofHD206301plottedagainstphotometricphasecal- period of12.1±0.2days.Thespotrotation12.2 from 0.009to0.018maginB.Theentrychosenforillustra- points, respectively,thefullamplitudesofanalyticalsin6 is only0.01mag. bital periodandthe11.1—0.5/+0.3daypseudosynchronous tion inFig.40andTable3comesfromtheseventhdataset’s but hasnotyetarrived. rotation periodimpliedbythe0.18±0.02eccentricity,sug- and sin20fitsrangedfrom0.006to0.017maginV first andfourthdatasets,whichcontainedonly10nine days withastandarddeviationof0.5day.Ifwediscountthe as manifestedbystarspotmodulation,isaround12days.The gesting thatHD206301isaimingforpseudosynchronism average ofthe16values(8datasetseachVandB)is12.2 region thatshowweaklinesofthesecondarywithaline- V lightcurve,withafullamplitudeof0.011magand tion. AnappropriatelyweightedspectrumofHR6608 that theHawingsareconsistentwithasubgiantclassifica- Ha coreissomewhatfilledinbyemission.Comparisonwith trum oftheHaregionwasalsoobtained,whichshowsthat for theprimaryand4±2kmssecondary.Aspec- ratio forB/Ais0.7whilethevsinivaluesare5±1kms rotation periodandi;sin¿=5kmsresultinaminimum lines makesclassificationdifficult,butslightlybetterfitsre- types fromG2VtoKOwastried.Theweaknessofthe to theprimarylines.Forsecondaryarangeofspectral most nothingotherthanastrometric informationwasknown radius fortheprimaryof1.2Æ,avalueconsistentwith the componentsasG2IVandG2—5V.Themean12.2day similar spectraofsolar-typedwarfsandsubgiantsindicates strength ratioforB/Aofabout0.2.Thepreliminarymass catalog, andoneradialvelocity wasobtainedattheDomin- emission features.Previousto this importantrevelation,al- ±0.5 daysismidwaybetweenthe13.1740±0.0001dayor- about thestar.Theonlyspectral typeisK0fromtheHD cant notorietywithhisdetection ofitsstrongCaIIHandK sulted withtheearlierspectraltypes.Asaresult,weclassify (G2 IV;Strassmeier&Fekel1990)providesaverygoodfit subgiant classification. 0 © American Astronomical Society • Provided by the NASA Astrophysics Data System We haveobtainedanumberofspectrainthe6430Â Bidelman (1991)firstlaunched HD208472intosignifi- > < -2.05 -2.06 -2.03 -2.04 6.37 HD208472 Photometric Phase -1 plotted inFig.41.Periodogramanalysisofthosedatagives Fig. 41.LightcurveofHD208472plottedagainstJuliandate.Thephoto- relatively large,0.36mag,consistentwiththestarbeing for HD208472.Thesecondhalfoftheseasonis metric periodis22.54days,andtheamplitudeinV0.36mag. quite active.Lightcurvesfromtheotherseasonshave the rotationperiodP=22.54±0.05days.Theamplitudeis able tolocateanyUBVphotometryofthisstar. ion AstrophysicalObservatory(Redman1938).Wewereun- kms. Ithasanorbitalperiodof22.6daysandanearly is asingle-linedspectroscopicbinarywithvsin/=21±2 in minimumbrightness. constant, andthechangingamplituderesultsfromvariations amplitudes. Themaximumbrightnessremainsapproximately same shapeandperiod,butwithslightlylargersmaller circular orbit.Itsrelativelylargerotationalbroadeningmakes it moredifficulttodeterminethebestspectraltype.However, pler imaging. tude spotvariations,isconfirmedbyitsHaprofile.Ourlone 208472 isaveryactivestar,assuggestedbyitslargeampli- ods makethegiantstarasynchronousrotator.ThatHD dius is9.4R.Itsnearlyidenticalrotationandorbitalperi- type. Fromitsvsiniandrotationperiodtheminimumra- of HD208472andsoweclassifyitastheformerspectral vides aslightlybetterfitthanßGem(K0III)tothespectrum have rotationalmodulationcaused bylargedarkstarspotre- become chromosphericallyactive (Hall1991,1994)and tional broadening,thissystemisagoodcandidateforDop- only inroughlyahalfdozenofthemostchromospherically an appropriatelybroadenedspectrumofkGem(G8III)pro- with a50dayrotationperiod isspinningfastenoughto period hadbeenreportedearlier byGriffin(1990).Itwas active giantsandsubgiants.Thus,despiteitsmoderaterota- above thecontinuum.Suchemissionstrengthhasbeenfound spectrum ofHashowsthatthislinehasmodestemission listed asacandidateinCCABS IIbecausealate-typegiant with anorbitalperiodof50.119 days.Asimilarvalueforthe (1991) showedittobeaneclipsingbinaryinacircularorbit ö We havephotometricdatafromthreeobservingseasons Our numerousspectroscopicobservationsshowthisstar We putHD223971onourprogramafterGriffinetal. 9250 93009350 6.38 HD223971 Julian Date(2,440,000+) 2957 1995AJ 110.2926H -1 ellipticity effectandspots,eachwithanamplitudeofjustover0.01magin points arenotshown.Thelightvariabilityiscausedbyacombinationofthe from theephemerisr(conj)=2447174.85+50.1\9E.Acoupleofeclipse Fig. 42.LightcurveofHD223971plottedagainstorbitalphasecalculated 2958 HENRYETAL:CHROMOSPHERICALLYACTIVESTARS nation, asofThe72ndNameListVariableStars(Ka- HD 223971hasnotyetbeenassignedavariablestardesig- also notedthatitwasadouble-linedspectroscopicbinary. & Kuji1990),andF8(AbtWillmarth1994).Thelatter contact, andmightbetotalforabout0.5hr(Griffinetal. and 0.85inU,lastsabouttwohoursfromfirsttofourth gions. Primaryeclipsehasadepthof0.40inV,0.65B, rotation period.AFourierfitassumingtheorbitalperiod percent ineachcase,butwedonotincludethemherebe- primary andsecondaryeclipse,whichshowafadingoffew is availableforHD223971.Thelow-amplitudelightvaria- zarovets &Samus1995). pear inourred-wavelengthspectra. Preliminaryresultsof plitude of0.012±0.002mag.InFig.42thedataareplotted places thespotminimumatorbitalphase0.84withanam- near theorbitalperiod,andthereforeispresumablyspot effect. Asecond,strongerperiodisfoundat53±1.3days, mum ofthecos26variationatorbitalphase0.97±0.04,con- tions thatarepresentsuggesttheexistenceofbothellipticity This valueandtherotationperiod resultinaminimumradius red wavelengths,linesofthelate-typestararesignificantly amplitude of0.013±0.002mag,istheresultellipticity firming theliklihoodthatthisvariation,havingafull tions. Periodogramanalysisfindsaperiodat24.6±0.3days, cause theyweretakenduringmarginalphotometriccondi- and spots.Wealsofindacoupleofobservationstakenduring V. Thespotrotationperiodis53days. the coolerstar.Wealsodetermine vsin/=6±lkms. the ellipticityandspotrotationeffectsdespitetheirverylow essentially synchronousrotation.Thisfigureclearlyshows ably theresultofellipticity.Fourieranalysisplacesmini- a valueveryclosetoone-halftheorbitalperiodandpresum- of 6.3Rq.Weakbroadenedlines ofthehotterstaralsoap- diluted bythecontinuumof hotterstar.Visualcompari- amplitudes. against orbitalperiod,sincethespotrotationperiodindicates +F9 III,(Abt1984),gG-bA(Bidelman1985a),GOIII(Sato son withourstandardsindicates aspectraltypeofG6IIIfor separation ofthiscomposite-spectrumeclipsingbinary.At 1991). SpectralclassificationsfoundintheliteratureareAm © American Astronomical Society • Provided by the NASA Astrophysics Data System Only onecompleteseasonofphotometryfromoursurvey In 1990weobtainedtwospectranearmaximumvelocity > < -0.13 -0.14 -0.15 -0.16 0 0.20.40.60.81.0 Orbital Phase -1 rotational broadeningofroughly50±10kms. calculated fromtheephemerisHID2449400.0+2.693E.Theamplitude Fig. 43.LightcurveofHDE337518plottedagainstphotometricphase a late-AstarsincenumberofFeIlinesarevisibledespite in Vis0.06mag. plotted modulothisperiodinFig.43.Therotationalampli- J1906+274. Follow-upspectroscopybyMulliss&Bopp came fromBidelman’s(1983b))detectionofweakCallH ing seasons.Periodogramanalysisofthefirstseason’sdata counterpart totheROSATextremeultravioletsourceRE and Kemission.Thus,itislistedwithothercandidatesin spectrum subtractionsuggesttheresidualisthatof tude isapproximately0.06mag.Anotherperiodnearlyas gives theperiodP=2.693±0.005days.Thosedataare etry ofit. vided abriefsummaryoftheiropticalresults.Theycon- and CaII8542Âlinespartiallyfilledbyemission.Jeffries pected. Theamplitudeoflight variations inthesecondob- ter makingtheabovechoicewediscoveredworkofJef- orbital inclinationisparticularlylow,around24°,thenthe own spectroscopicresultsareconsidered.However,ifthe P =2.693becausethisperiodismoreprobablewhenour orbit. AsTable2shows,wecouldfindnopublishedphotom- cluded ithasanorbitalperiodof2.73daysandacircular et al.(1994)alsodetectedtheduplicityofthisstarandpro- CCABS II.Poundsetal.(1993)identifieditastheoptical maximum brightness.Thisimplies additionalspotcoverage this short-periodsystemissynchronouslyrotatingasex- their resultssupportourchoiceofperiodandindicatethat of theiranalysisandobservationsmaybesubjecttothe fries etal.(1994).Theirsummary,however,gavenodetails strong asthefirstappearsat1.59±0.002days.Weassume > in thesecondseasonwithadistribution moreuniformin (1994) foundthestartobeadouble-linedbinarywithHa < longitude sothattherotational modulation islessened. serving seasonisonlyabouthalf asgreatinthefirstsea- son, primarilybecauseofa0.04 magdecreaseinthelevelof same aliasingproblemsthatweencountered.Nevertheless, 1.59-day periodcouldrepresentthetruerotationperiod.Af- An indicationthatHDE337518isanactivesystemfirst We havephotometryforHDE337518fromtwoobserv- 0.15 0.10 0 0.20.40.60.81.0 6.39 HDE337518=BD+27°3245 Photometric Phase 2958 1995AJ 110.2926H -1 _1 -1 B —Vindicesimplyalargeultraviolet excessofaboutE(U both CCABSIandCCABSII.Spiteetal.(1984)stressedthat result ofahotcompanion, result whichPetersonetal poor with[Fe/H]=-0.75anddeterminedusin/=10±3 this systemischemicallyandkinematicallyoldbut,some- present inbothcomponents,theHaemission,andMgII kms. Thesystemiscloseenoughtohaveameasurable variable, determiningP=3.7584daysatalaterepoch. tionally foundithighlyprobablethattheorbitalperiodis what oddly,hasmeasurablelithiumabundance.Theyaddi- emission (Rucinski1985)earnedBD-0°4234alistingin period of3.7569days.Basedontheirderivedtemperatures be adouble-linedbinaryincircularorbitwithanorbital mined. Wealsofoundvsin/=11±2kmsfortheprimary dicates thatthesystemissynchronously rotating. plot appearsinFig.44,wheretheamplitudeisabout0.05 is up.Periodogramanalysisofthesecondhalffirst our APTsiteisshutdowntoprotectagainstlightningstorms comes tooppositionwiththeSunduringmid-summerwhen range seenintheVmagnitudeslistedourTable2,BD trigonometric parallaxof0'.'025(vanAltena1995).AsNSV Spite etal.(1994)foundthesystemtobemoderatelymetal constant inthespectrum.ThestrongCailHandKemission for thetwocomponents,theyclassifiedstarsasK3Ve even today,isthatofPetersonetal.(1980),whofounditto radius of0.58R. combined withaperiodof2.69daysresultsinminimum and 11±3kmsforthesecondary.Theprimary’svsin/ lem, spectraltypesofKOVandK3fortheprimary K dwarfsarenotcompletelysatisfactory.Despitethisprob- to thoseofHDE337518andsovariouscombinationsthe line strengthsofourK-dwarfstandardsareweakcompared with alineintensityratioofabout0.25.Unfortunately,the 2959 HENRYETAL:CHROMOSPHERICALLYACTIVESTARS data. Comparisonofthephotometric andorbitalperiodsin- mag. Scatterinthephaseplotissignificant,butwefind and becausewedonotobservethisfaintstarwhenthemoon Samus 1995). as ofThe72ndNameListVariableStars(Kazarovets& variable. Theoriginalsuspicionhasbeenattributedto secondary, respectively,appeartobereasonablywelldeter- find anyreliableperiodicitiesinthecheckminuscomparison season givesP=4.03±0.02days.Thecorrespondingphase a fewhundredthsofmagnitude.Despitethe0.12mag Krzeminski (1973)reporteddetectingdefinitivevariationsof ability amountingtoabout0.15maginV.Alittlelater, similar periodsinalloftheotherdatasets.Also,wedonot Sandage (1969),whofoundevidenceforprobablelightvari- -5) =0.25mag.Sandage(1969) proposedthatthiswasthe 13768 (Kukarkinetal.1982),BD—0°4234isasuspected +K7 Ve,wherethe‘V’referstoHaemission,whichwas —0°4234. However,thosedataaresparsebecausethestar -0°4234 hasnotyetbeengivenavariablestardesignation Q © American Astronomical Society • Provided by the NASA Astrophysics Data System The mostimportantpaperpertainingtoBD-0°4234, As notedpreviouslybySandage (1969),theU-Band Our photometricdatacovertwoobservingseasonsforBD Our spectraat6430ÀshowthatthestarsareKdwarfs 6.40 BD—0°4234 -1 -1 -1 Æ -VisalmostexactlyrightforanunreddenedK3star, primary and6±2kmsforthesecondary.Thestaris excess istheresultofacombinationchromospheric Fig. 44.LightcurveofBD-0°4234plottedagainstphotometricphase tifying itwiththehaloPopulation II.Suchametallicityap- features typicalofchromosphericallyactivestars.Theyalso part toanEinsteinx-raysource,Bergoffenetal.(1988)ob- history. Asaresultofitsidentificationasanopticalcounter- rotational broadening,is0.56R. were comparedtotheslightlymetal-poorstarseEri(K2V) clearly metalpoorandunfortunatelywedonothaveany B/A isabout0.25.Thevsin/’sare7±1kmsforthe lined phase.Inthe6430Âregion,line-strengthratiofor KPNO, weobtainedonespectrumofthissystematadouble- little reddening. activity andtheoldchemicalcomposition.Theobserved calculated fromtheephemerisHID2449200.0+4.03£.Theamplitudein noted astrongCanKemissionline,velocityvariations,and tained anultravioletspectrumofitthatshowedemission the primary,resultingfromrotationperiodandprojected and thedistanceofabout60pcsuggeststhatthereshouldbe and circularorbitforthissingle-lined system.Lairdetal et al.(1988),whodeterminedan orbitalperiodof1.844days obtained high-resolutionopticalspectrafromwhichthey analysis byPetersonetal.(1980).Theminimumradiusof identical tothosederivedfromaspectroscopic-abundance tral typesareapproximatelycorrect,andsoweclassifythe and HD156026(K5V;Houk1982).Thecriticallineratios significantly metal-poorKdwarfstandards.Thecomponents Our interestinthissystemstems fromtheworkofLatham in theextremeultravioletwithROSAT(Poundsetal.1991). and obtainedUBVRImagnitudes.Thestaralsowasdetected a vsin/of22kms.TheylisteditsspectraltypeasG5V and thebroadeningoflinewingssuggestthatthosespec- (1988) determinedametallicity [m/H]=-2.12,makingBD spectra asK2:VandK5:V.Thus,ourroughtypesarenearly (1980) provednottobethecase.Instead,itislikelythis V is0.05mag. + 13°13anextremelymetal-poor starandpresumablyiden- Q During ourmostrecentspectroscopicobservingrunat BD +13°13hashadaninterestingandslightlycheckered 2.35 - 2.30 - 0 0.20.40.60.81.0 6.41 BD+13°13 Photometric Phase 2959 1995AJ 110.2926H peared toconfirmthatofCarbonetal.(1987),whoused primary asasubgiant,andalsoobtainedvsin/=23±3for found muchhigherabundances.Pilachowskietal(1993) termine an[Fe/H]=—2.14.Morerecentstudies,however, Fig. 45.LightcurveofBD+13°13plottedagainstphotometricphasecal- the followingseasoncloselyresembles thatofthefirst. There isconsiderablescatterin thephasecurvebecauseof where theamplitudeisseento be approximately0.05mag. riod ofLathametal.(1988)whiletheotherperiodsareas- rotation periodbecauseitcloselyagreeswiththeorbitalpe- 0.649±0.001, 0.684±0.001,1.852±0.003,and2.171±0.003 photometric datagivescomparablystrongperiodicitiesat lent widthsfromasecondspectrumofthisstarandcorrect- Pilachowski etal.(1993)inadvertentlyusedthewrong the primary.Pasquini&Lindgren(1994)detectedCallK abundance studydetermined[Fe/H]=—0.5,identifiedthe discussed below.Spiteetal.(1994)inamoreextensive obtained [Fe/H]=-1.3,whichhasrecentlybeenrevisedas is 0.05mag. culated fromtheephemerisHID2449200.0+1.852E.TheamplitudeinV 2960 HENRYETAL:CHROMOSPHERICALLYACTIVESTARS days. Ofthose,wepresumethat1.852daysrepresentsthe feature at6707Â. width, correctedforsecondarylight,of47mÂtheLi+Fe ing forthelightofsecondarystarfollowingSpiteetal. equivalent widthsintheirabundanceanalysis.Usingequiva- tification ofanotherobservationasG30-52=BD+13°13, in theabundanceresultsforBD+13°13.Duetoamisiden- eight observationsobtainedovera10dayintervalproduced emission fromboththeprimaryandsecondary.Thethree spectrum synthesisofintermediate-resolutionspectratode- short-term variationsinthelight curve.Thelightcurvefrom season areplottedversusthe1.852 dayperiodinFig.45, discovery ofthissystem’sphotometricvariability.Their sumed tobealiasesofthetrueperiod. Thedatafromthefirst sistent withSpiteeta/.’sresults.Theyalsofindanequivalent orbital periodof1.844dayswasused. about 0.08maginVwhenaperiodnearlyidenticaltothe a quasisinusoidalvariationandpeak-to-peakamplitudeof sets ofUBVmagnitudesinTable2showarange0.09 (1994), theyobtainanironabundance[Fe/H]=—0.62,con- V, andRodonoetal.(1994)publishedabriefnoteaboutthe < > © American Astronomical Society • Provided by the NASA Astrophysics Data System Periodogram analysisofthefirstourtwoseasons Pilachowski etal.(1995)reportedthefollowingrevision 0.10 0.08 0.06 0.04 0 0.20.40.60.81.0 Photometric Phase 1 -1 1 primary’s criticallineratiosandoverallspectruminthe6430 À region.AcomparisonwithrCet(G8V),whichhas for B/Aisabout0.1at6430Â,accountingthesignifi- the primary,andoneofcriticallineratiosdoesnotfit.If have nospectraofsignificantlymetal-poorsubgiantssowe ratios, resultinginanunsatisfactoryfit.Unfortunately,we cause oftheconclusionfromspectrum-synthesisabundance cantly increasedestimateduncertaintyforthesecondary.Be- and Favataetal.(1995).Theabsorptionline-strengthratio with thatofBergoffenetal.(1988)andSpite(1994) rough agreementwithrecentdeterminationsfromhigh- the primaryisindeedadwarf,thensecondarymustbeof ever, itslinesaretooweakcomparedtothedilutedof metal-poor dwarf¿Boo(G8V;Wilson1962)with[Fe/H]= metal-poor dwarfs.Aweightedspectrumoftheslightly next comparedthespectrumofBD+13°13withthose which hasasolarironabundance,provedtobethemost G5-K0 subgiants.Althoughthespectrumof/3Aql(G8IV), et al.1994),wefirstcompareditsspectrumtothoseof work thattheprimaryofBD+13°13isasubgiant(Spite the primaryandusin/=14±5kms“forveryweak Latham etal.(1988)discovered ittobeasingle-linedbinary BD +13°13hasanironabundancemuchclosertothesolar mined fromourvsiniandrotationperiod,isconsistentwith considerably laterspectraltype.Althoughthelinesof [Fe/H]=-0.38±0.04 (Taylor1994),wastriedaswell.How- similar, theagreementispoorforoneofcriticalline secondary features.Ourvaluefortheprimaryisconsistent are rotationallybroadenedwithvsin/=19±2kmsfor H]=—0.4. Theyalsodetermined vsinz'=5±3kms“. concluded thestarisprobably a subgiantandobtained[Fe/ with aperiodof6.57daysand acircularorbit.Lairdetal. Previously, inaradial-velocitysurveyofmetal-poorstars, et al.(1991),whoshowedthatithasweakCailKemission. enough tocausesuchadiscrepancy. continuum ofthemuchfaintersecondaryisunlikelytobe ferent techniques.Thedilutionoftheprimary’slinesby earlier tothissystembytwodifferentgroupswhouseddif- value thantheextremelylargemetaldeficiencyattributed dispersion spectrograms.Thoserecentresultssuggestthat either adwarforsubgiant.Ourestimatedabundanceisin and thatthemetallicityofthissystemisrathercloseto our spectrumcomparisonsuggeststhatbothstarsaredwarfs of ¿Boo(G8V)andHD156026(K5V;Houk1982).Thus, fit canbeobtainedwithanappropriatelyweightedspectrum sorption featuresofthesecondary.Linesbothcomponents subgiants, whichmightproduceadifferentresult. solar value.Wecaution,however,thatthespectrumofBD secondary arequiteweakandbroad,areasonablecombined (1988) foundittobesomewhat metalpoorwith[m/H]= -0.20 ±0.08(Taylor1994)providesaverygoodfittothe -0.67. Fromaspectroscopic analysis Spiteetal.(1994) + 13°13hasnotbeencomparedwiththoseofmetal-poor In ourred-wavelengthspectrawehavedetectedweakab- Our interestinBD+30°2130wasarousedbyPasquini Our minimumradiusof0.7Rfortheprimary,deter- e 6.42 BD+30°2130 2960 1995AJ 110.2926H -1 2961 HENRYETAL:CHROMOSPHERICALLYACTIVESTARS Fig. 46.LightcurveofBD+30°2130plottedagainstphotometricphase calculated fromtheephemerisHID2449300.0+6.80E.Theamplitudein rotating. Becausetheamplitudedecreasedtonearlyzerodur- maximum forthetwoseasonsofdatawehave.Ourcheck that interval,theamplitudewasapproximately0.03mag,a only thedatabetweenJuliandate2449285and2449440.For ing theobservingseason,weshowaphaseplot(Fig.46)of gives P=6.80±0.02days,makingthestarsynchronously BD +30°2130.Periodogramanalysisofthefirstseason with severaldifferentGstarsindicatesanearly-Gspectral BD +30°2130showonlyonesetoflines.Visualcomparison V is0.03mag. trum ofHR4098(F9V),with[Fe/H]=-0.48±0.2(Taylor type. Acomparisonwithanappropriatelybroadenedspec- star HD99267isalsovariableanddiscussedseparately. > be intermediateinbothspectraltypeandabundance.How- ric periodandvsin/,isconsistentwitheitheradwarfor minimum radiusof0.94R,computedfromourphotomet- km s,consistentwiththeresultofSpiteetal.(1994).The and soweclassifythestarGlIV-Vestimate[Fe/H] difference betweenthespectraofsuchdwarfsandsubgiants, ever, asnotedpreviously,inthe6430Âregionthereislittle HR 483(G1.5V),with[Fe/H]--0.0±0.06,andappearsto spectra ofßCWn(GOV),having[Fe/H]=—0.18±0.06,and stronger. Itsspectrumwasthencomparedwithbroadened identified BD+36°2193asasingle-linedspectroscopicbi- subgiant. greater thantheorbitalperiod. For thatportionofthedata coherent lightvariations,which haveaperiodP=8.31 man 1985b)classifiedthestarG2. nary withaperiodof7.15daysandcircularorbit.Laird et al.(1988)determined[m/H]=-0.64.G.RKuiper(Bidel- 1994), showsthatthelinesofBD+30°2130aresignificantly set, shownmodulothatperiod in Fig.47,theamplitudeis — —0.1.ThelinesofBD+30°2130havevsini=l±l ±0.04 days,resultinginarotation periodthatis16% +36°2193. Thelasthalfofthefirst seasondisplaysthemost Q © American Astronomical Society • Provided by the NASA Astrophysics Data System So far,wehavecollectedtwoseasonsofphotometryfor Our twohigh-dispersionred-wavelengthspectrogramsof From asurveyofmetal-poorstars,Lathametal.(1988) We havetwoseasonsofphotometric dataforBD 2.15 2.14 2.16 2.17 2.18 0 0.20.40.60.81.0 6.43 BD+36°2193 Photometric Phase 1 -1 _1 1 calculated fromtheephemerisHID2449300.0+8.3IL.Theamplitudein Fig. 47.LightcurveofBD+36°2193plottedagainstphotometricphase found inthesecondseasonandalsoforBdataboth no evidenceofsecondarylines.Comparisonitsspectrum only about0.015mag.Identicalperiodsandamplitudeswere on averagethandatafromseasonone. BD +36°2193hasasomewhatearlierspectraltype.Asec- with thatofthemetal-poordwarfrCet(G8V), seasons. Season-twodataareapproximately0.01magfainter V isonly0.015mag. fit ofthelinedepths,butcriticalratiosindicatethat [Fe/H]=-0.38±0.04 (Taylor1994),resultsinanexcellent ond metal-poordwarf,/¿Cas(G5V),with[Fe/H]=—0.60 the starasG6Vandestimatethat[Fe/H]=—0.4.Thelinesof weak comparedtothoseofBD+36°2193.Thus,weclassify J2220+493. Aspartofasearchforchromosphericallyactive radius of0.66Æ• km s.Ourvsiniandrotationperiodresultinaminimum BD +36°2193areslightlybroadened,withvsinz'=4±l tical counterparttotheROSATextremeultravioletsourceRE troscopic observationsofthestar,findingthatbothitsHa Jeffries &James(1994)likewisefoundastronglithiumline noted thatthelithiumlinewasunusuallystronginthisstar and CaII8542Âlineswerefilledinbyemission.Theyalso stars, Mulliss&Bopp(1994)obtainedhigh-dispersionspec- and pointedoutthat,ifthestarisadwarf,itveryyoung. ±0.06 (Taylor1994),haslinesthataresignificantlytoo photometry. including individualvelocitiesandarevisedvsiniof15 is asingledwarf.Jeffries(1995)presentedupdatedresults as wellai;siniof20kms,andsuggestedthatthestar tral typeandvsin/,wouldgive areasonableminimumra- as therotationperiodofBD+48°3686. IntheBdatathis dius, wesimplyadopttheslightly stronger2.42dayperiod days. Sinceeitheroftheseperiods, combinedwiththespec- Periodogram analysisofthesecond seasonfindscomparably km s“.AsTable2shows,wecouldfindnopublishedUBV strong periodsatP=2.42±0.01 daysandP=l.70±0.01 0 Our twored-wavelengthspectraofBD+36°2193show Pounds etal.(1991)identifiedBD+48°3686astheop- We havetwoseasonsofphotometryforBD+48°3686. 0 0.20.40.60.81.0 6.44 BD+48°3686=SAO51891 Photometric Phase 2961 1995AJ 110.2926H _1 1 -1 -1 -1 period isalsofoundasthesomewhatstrongeroftwo. first observingseasonisessentiallythesameassecond. variation inthedepthofminimum.Thelightcurvefrom Data inVfromthesecondobservingseasonareplotted calculated fromtheephemerisHID2449600.0+2.42£\Theamplitudein Fig. 48.LightcurveofBD+48°3686plottedagainstphotometricphase has arelativelylargeloglithium abundance.Ambrusteretal. rapidly rotatingstaroftypeK5IV.Significantlyrevised Fleming etal.(1987)concludedthatBD+70°959isasingle nary withaperiodlessthanfewdays.Shortlythereafter, because Silvaetal.(1985)haddetectedstrongCaHandK Rq ,indicatinganinclinationcloseto90°.Weagreewiththe Jeffries &James(1994)whileourusin¿=16±1kmsis from fourobservations,supportingtheconclusionthat km s"showsnoevidenceforvariabilityandisinexcellent of BD+48°3686.Ouraveragevelocity-19.8±0.2 approximately 0.08mag,butwithsignificantcycle-to-cycle against the2.42dayperiodinFig.48.Theamplitudeis § 2962 HENRYETAL.:CHROMOSPHERICALLYACTIVESTARS et al.(1995).Thoseauthorsalso determinedthatthisgiant et al.(1991),wherefollowed byFekel&Balachandran conclusion thatthestarissingle, firstappearedinAmbruster kms, anddespiteanapparentlyconstantradialvelocity, emission, estimatedarapidrotationofi;sin/=30-40 on ourprogramandincludedasacandidateinCCABSII des clusterorpossiblyyounger. conclusion ofMulliss&Bopp(1994)andJeffriesJames nearly identicaltotherevisedvalueofJeffries(1995).The lithium linesimilartothatofMulliss&Bopp(1994)and type ofKlV.Wedetermineanequivalentwidththe agreement withJeffries(1995)averageof-19.4kms suspected itmightbeasynchronouslyrotatingstarinbi- v siniandrotationperiodresultinaminimumradiusof0.77 star issingle.Comparisonwithstandardsindicatesaspectral V is0.08mag. (1993), andaremoreextensively discussedinAmbruster spectroscopic parametersforBD+70°959,includingvsin/ (1994) thatBD+46°3686issimilartotheageofPleia- (1995) showedthestartobe200-400 pcabovethegalactic = 19kmsandaspectraltypeofK0IIIaswellthe © American Astronomical Society • Provided by the NASA Astrophysics Data System BD +70°959isastronglyemittingx-raysourcethatwas So farwehaveobtainedfourspectroscopicobservations 1.40 1.45 1.35 1.50 0 0.20.40.60.81.0 6.45 BD+70°959=ETDra Photometric Phase -1 -1 -1 ported lowamplitudephotometricvariabilitywithaperiod plane, indicatingthatitbelongstotheIntermediate-oreven extensive UBVRIphotometrythatshoweddefinitevariabil- of afewdays.Morerecently,Jetsuetal.(1992)presented calculated fromtheephemerisHID2449300.0+14.24E.Theamplitude Fig. 49.LightcurveofBD+70°959plottedagainstphotometricphase their UBVRphotometrywasconsistentwithaK0-1III metric periodof13.982±0.008days.Theyconcludedthat ity, withafullrangeofalmost0.3maginVandphoto- Old-Disk population.Inanabstract,Berginetal.(1988)re- in Vis0.23mag. We notethatthemeanvelocityofoursevenobservations the firsttwoseasonshaveslightlysmalleramplitudesof third seasontheamplitudeofvariabilityis0.23magwhile data givestherotationperiodP=14.24±0.02days, Table 2aremeanstakenfromJetsuetal.(1992,II, in asingle-linedbinaryormerelyconsequenceoflinepro- could notdecidewhetherthiswasevidenceoforbitalmotion riod of13.91±0.02daysandanamplitude5kms,but moderately rapidlyrotatingchromospherically activesingle result fromthemoderatelinebroadeningcombinedwith that itisasinglestar.Apparentvelocityvariationsprobably km sareextensivelydiscussedbyAmbrusteretal.(1995). 0.17 mag. of theFKComaetype,inThe72ndNameListVariable the photometryofBerginetal.(1988)andJetsu file asymmetriesinasinglespottedstar.Onthestrengthof giants (Fekel&Balachandran1993). giant is5.3R.Thisstaranother memberofthegroup distorted lineprofilesduetothechangingspotdistribution alone is12.2±0.3kms,consistentwiththeassumption as wellourspectraltypeofK0IIIandvsin/=19±2 slightly longerthanthevalueofJetsuetal.(1992).For subset 2). Stars (Kazarovets&Samus1995).Themagnitudesinour spectral type.From9radialvelocitiestheyalsofoundape- on thisveryactivestar.Theminimum radiusofthisunusual (1992), BD+70°959wasdesignatedFTDra,asavariable +70°959 isplottedinFig.49.Periodogramanalysisofthose +70°959 makeitsevolutionary stateuncertainsincethe Q As mentionedabove,theconclusionthatstarissingle The thirdofourthreeseasonsphotometryforBD The unusualrapidrotationand lithium abundanceofBD 0 0.20.40.60.81.0 Photometric Phase 2962 1995AJ 110.2926H -1 -1 -1 -1 nary classificationofG5:V.Observations ofadditionalstan- likely adwarforperhapssubgiant. Thus,wegiveaprelimi- of thewingsindicatesthat star isnotagiantbutmore phase plotindicatessignificantcycle-to-cyclevariation. mid-G isestimated.Whilethe Ha linecoreissignificantly riod. ThefirstseasonisplottedmodulothisperiodinFig.50. pre-main-sequence candidate.InarecentpaperFavataetal depleted thesurfacelithium. filled inbyemission,ithasrather broadwings.Thestrength mine anaccuratespectraltype inthe6430Àregion,but velocity of13.6±0.2kms,supportingFlemingetal.'s The amplitudeisroughly0.12magbutthescatterin erations discussedbelowleadustopreferthe1.145daype- The secondseasongivesnearlyidenticalresults.consid- ods inthefirstseasonare0.525,0.884,1.145,and7.76days. the identificationoftrueperiod.Thefourstrongestperi- moon isup.Therefore,aliasesintheperiodogramcomplicate APT toacquireitandbecauseisnotobservedwhenthe a vsin/of50kms.Favataetal.(1993)foundthatthe it wasapparentlysingle,classifiedK0III,anddetermined x-ray emissionsource1E2349.8-0112.Theyconcludedthat lar tothescenarioarguedforFKComae(Bopp&Rucinski calculated fromtheephemerisHID2448900.0+1.1451s.Theamplitude Fig. 50.Lightcurveof1E2349.8-0112plottedagainstphotometricphase cause ofthislinebroadening,itisratherdifficulttodeter- the fainteststaronourobservingprogram.Thedataare the rapidrotationmightresultfromacoalescedbinary,simi- in Vis0.12mag. As Table2shows,wefoundnopublishedUBVphotometry star hasastronglithiumlineandproposedthatitislikely 2963 HENRYETAL.:CHROMOSPHERICALLYACTIVESTARS sparse becauseitsrelativefaintnessmakesitdifficultforour of thisstar. single giantislocatedwellabovethegalacticplane.While (1989) claimthatthestarissingle.Wedeterminevsin/=41 (1995) determinedvsin/=64kmsfromtheirspectrum. 1981; Bopp&Stencel1981),suchcoalescenceshouldhave ±3 kms,significantlysmallerthanpreviousvalues.Be- > Fleming etal.(1989)identifiedalate-typestarwiththe From sixspectroscopicobservationswedetermineamean © American Astronomical Society • Provided by the NASA Astrophysics Data System We havetwoseasonsofphotometryfor1E2349.8-0112, 3.10 3.05 -. 3.00 - 2.95 - 0 0.20.40.60.81.0 6.46 1E2349.8—0112 Photometric Phase -1 -1 -1 period inFig.51.Therotational amplitudeisapproximately 0.04 mag.Thesecondseasongives thesameresultsexcept Data fromthefirstseasonareplotted moduloour1.487day resolution spectroscopicobservationsshowedHaandthe riod of1.145days,whichresultsinaminimumradius cussed below,webelievethat the shorterperiodiscorrect. but analiasofcomparablepowerexistsatP=3.04±0.01 he presentednophasediagramnorlightcurveofanysort. claimed ittobevariablewithaperiodof3.06days,although nally, inthecourseofalong-termmonitoringprogram nication fromR.Mathieu,whoreportedashortorbitalperiod by suggestingthatthestarislikelyanRSCVnorrelated was notapre-main-sequencestar.Walter(1986)concluded ever, hefoundnolithiumabsorption,indicatingthatthestar Can HandKlinesinemissionwhiletheupperBalmer fields, althoughitsx-rayfluxwashighlyvariable.Hislow- Tauri starfoundtobeabrightx-raysourceintheTaurus 0.93 Rq,althoughthe0.88dayperiodiscertainlyalsopos- blom etal.(1993b)havefoundthreeGdwarfrapidrotators ric periodof7.8daysbecausethatwouldimplya claimed byGrankin(1994).On thebasisofresultsdis- menu and,thus,fortwoseasonshastestedtheobserving confirm orrejectourassumedperiod. in thePleiadeswithrotationalvelocitiesofnearly40kms. tional velocitiesof57and44kms,respectively.Soder- two remainingperiods,0.88and1.145days,resultsinrota- ity of95kmswouldresult.Asimilarassumptionwiththe equaled thesolarvalue,anextremelylargerotationalveloc- the shortestperiod,0.525days,isalsoanalias;ifitsradius minimum radiusof6Rq.Likewise,wehaveassumedthat further. days. Infact,thelatterperiodis practicallyidenticaltothat limits ofourtelescope.Periodogramanalysisthefirstsea- Comparison oftheUBVphotometry(Table2)Walter and thatthesystemwasnotamemberofTauruscloud. firmed itslackoflithiumandrevealedittobeadouble-lined series wasobservedtobeinemissionononeoccasion.How- stars. TheobjecthecalledTau1wastheonlyearly-Knon-T spectroscopic dataforanumberofpossiblepost-TTauri On thissomewhatarbitrarybasiswehaveassumedthepe- dards obtainedatHaareneededtoconstrainitsspectraltype sample ofsupposedweakTTauristars,Grankin(1994) spectroscopic binary.Theyalsomentionedaprivatecommu- others. Martinetal.(1994)obtainedaspectrumthatcon- candidate inCCABSII.ItsassociationwithpossibleTTauri obviously strongactivity,Strassmeieretal.(1993)madeita sible. Obviously,additionalobservationswillbenecessaryto son’s datagivestherotationperiodP=1.487±0.002days (1986) andMartinetal.(1994)mayhintatvariability.Fi- system withaspectraltypeofKOIV.Onthebasisits (1986). Inthatpaperhediscussedx-ray,photometric,and stars haspromptedadditionalobservationsofthisstarby Wa Tau1isoneofthefainteststarsonourphotometric Our interestinthisstarwasarousedbytheworkofWalter Our dwarfspectralclassificationeliminatesthephotomet- 6.47 WaTau1 2963 1995AJ 110.2926H -1 Bidelman, W.P.1985a,AJ,90,341 Bidelman, W.P.1985b,ApJS,59,197 Bidelman, W.P.1991(privatecommunication) Bidelman, W.P.1983b,AJ,88,1182 Bidelman, W.P.1983a(privatecommunication) Bessel, M.S.1990,A&AS,83,358 Bergoffen, M.J.,Stocke,Walter,E,&Fleming,T.A.1988,PASP,100, Bergin, E.A.,Fritz,M.L.,Guinan,E,Innella,G.,Leckenby,H.,Mc- Benz, W.,&Mayor,M.1984,A&A,138,183 Beavers, W.L,&Salzer,J.1983,PASP,95,79 Beavers, W.L,&Fitter,J.1986,ApJS,62,147 Ambruster, C.,Guinan,E.F,&Siah,M.J.1991,BAAS,23,941 broadenings of16±2kms.Thecriticallineratios ratio isabout0.67andbothstarshavesimilarrotational nights withseeingabout1"orbetter.Ourhigh-dispersionred Batten, A.H.,Fletcher,J.M.,&MacCarthy,D.G.1989,Publ.Dom. Basri, G.,Wilcots,E.,&Stout,N.1989,PASP,101,528 Basri, G.,&Marcy,G.W.1994,ApJ,431,844 Barden, S.C.1985,ApJ,295,162 Bahúnas, S.L.,etal1995,ApJ,438,269 Baliunas, S.L,etal1983,ApJ,275,752 Argue, A.N.1963,MNRAS,125,557 Ambruster, C.W.,Fekel,F.C.,Guinan,E.F.,&Hrivnak,B.J.1995(un- Abt, H.A.,&Willmarth,D.W.1994,ApJS,94,677 mag. Fig. 51.LightcurveofWaTau1plottedagainstphotometricphasecalcu- Abt, H.A.,&Levy,S.G.1976,ApJS,30,273 Abt, H.A.1984,ApJ,285,247 late-G andearly-Ksubgiants,includingtheKOIVtypesug- the meanmagnitudeofstarhasdecreasedabout0.04 0.04 mag. tively. 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