Revista Mexicana de Astronomía y Astrofísica ISSN: 0185-1101 [email protected] Instituto de Astronomía México

F. J. Moffat, Anthony A GLOBAL ASSESSMENT OF WOLF-RAYET BINARIES IN THE Revista Mexicana de Astronomía y Astrofísica, vol. 33, 2008, pp. 95-101 Instituto de Astronomía Distrito Federal, México

Available in: http://www.redalyc.org/articulo.oa?id=57116159033

How to cite Complete issue Scientific Information System More information about this article Network of Scientific Journals from Latin America, the Caribbean, Spain and Portugal Journal's homepage in redalyc.org Non-profit academic project, developed under the open access initiative © 2008: Instituto de Astronomía, UNAM - Massive : Fundamental Parameters and Circumstellar Interactions Ed. Paula Benaglia, Guillermo Bosch, & Cristina Cappa W no to du W sitiv mine 6128, plosiv Key R suggestions binaries, Los binary Massey step including stars, (1) stars las se inici Virpi estrellas se Massey binaridad T estrellas ser despu systematically sobre In in ha erminar evMexAA C/W C/W v v the 1 han pueden Mon the the a W e incertidum D concluido una ´ estudios e, e Wor of ´ epartemen b Succ. explosion, for olf-Ra ´ e es (no w propiedades Niemela, after am een t en complicado distances. O) O WR a this coal A M et et frecuencia ds: y de WR binarit WNE, ´ as e bien ´ egan the de parallel stars!). parte hamp the explorar al. C-V, al. con b GLOBAL P y binaries: P for one (Serie pro frequency efore et dust emp eter to eter t tic, cono , t p 144 bres para initial for metallicit prob comprehensiv das algunas or 1. (WR) de future ject y Mon a their ered a go en ´ Canada ıricos un ´ and Bartzak v INTR el Ph Bartzak in the cidas generales kno es in a ast de These binaria en las p Being tr e la sistem´ colab is general ysique, ten or tercer en conditions, b ´ eal, presumed prop a to the stars use Confer wn y Nub las w SMC. b estrellas optical extensos in las mine sugerencias tionally eing ODUCTION las ork. h lo en (moff[email protected] y QC effects uge oraci´ ASSESSMENT os them distancias. w (Z) erties MC problems os aticamen b the e enormes WR Univ estudian las are er oth binarias, — de (W Menor. H3C e wrapp encias) Here (W disparities and of Z, on empirical sp WR last stars: NM, lik las WR ersit C) to MCs normal reflect the core-collapse de of C) sough mostly ectroscopic (3) 3J7, e con carb extract w estrellas lo in ´ e ed te the la stage stars, para te ISM en , disparidades cono definidas e all w Aqu fundamen de colliding a 33 and 1998 MA Estos as ev los will t er up Virpi de on/o in canary 1998 menor Mon en but oluci´ with , b in studies that ´ in cidas initial ı traba et 95–101 Observ a efectos treal.ca). do b (esp as information resumimos summarize GELLANIC y apparen and am w tr v xygen WR. the problemas ctorado An disapp ery Niemela, on program y ´ eal, een the defined resp formed p tal ecially bas winds, sup Z, en jo in C thon or C atoire OF metallicit a Galaxy of sen- ´ edric C.P v Ahora ABSTRA third ´ parameters edric the futuro. (2008) de ex- en (3) la ect er- RESUMEN los anzada n in adv t ear ub y . NMM menor el brigh [Olivier W b vien and cat´ F. los es to the anced y F un F on do brillo , desaparecen in o en OLF-RA o the J. alogos (2) y y ellmi examine ellmi tos ctoral pun tness de (4) general amplio highligh the (en Galacto whic n ab in them. disk, the ilar WN small W SMC, CT 2006 en (Z). Moffat metalicidad um — CLOUDS catalogues the massiv estrellas Sc CL; aparen out tos en the v la ese Magellanic ery mix (WNE) (WNE) to stars: b hn h stars; and Ov de studen el ers colisi´ close Galaxia, n increased sobresalien in the t This and outer urr prop 1 that en um programa wice all ts er ultimo cen ´ massiv Breysac e- of YET turn te in en of tonces, W of b t effect W on, masiv quien of terstellar tric w increased WR to ers y erties is t differen olf-Ra of las in en solar o C this extremit of inicial [Olivier the la dep no e y decades R paso the 2002] ev (2) stars prev distance her 2002]. Clouds Nub Breysac extinci´ WNLha presence BINARIES as subt is (4) cerca tes ha b olution = w ends (then y of esp in etter et una ev outer ork. a ail t et (Z). de es 16 WR traba extinction, dominated estrellas de yp to tra the ectrosc´ en n WR y Sc al. um there. de on de on este ago El es ma of her kp este em (MCs), reflected ab v hn more These (e.g. Desde via stars. stars. ´ es Galaxy cen b 100) the jado of para Magallanes atmosf c. in subt the programa out y urr bark ers I pro or et de opico traba tral W H b the m metallicit This pronounced, egan, v w presencia Galactic of al. y yp 100) la y olf-Ra en include la uy No in an I hace b and on ecto orking where , extraer IN ´ y erica, than regions will WNE es LMC fase Nub i.e. jo. las w para WNE for W masiv der this is kno as b partly in est´ dos y incluy CE y end THE Estos estrellas de ´ (NMs), probably et e the dominated in Huc a y one as uncertain (1) on 2006 is wn pro stars. a star-forming Ma examinar , informaci´ as de (WR) W and the ´ to d function stars, ı going a with quite LMC ´ ecadas the como h olf-Ra e in a ject, y pun although MC WNLha. can H incluy subsolar t or, the relativ v las normal lac 2001), olving In donde en WNL WNL to some stars from ev y king sim- WR wh no also and last ties 144 p the y las on b y de de en en 95 or et of la w o y y e © 2008: Instituto de Astronomía, UNAM - Massive Stars: Fundamental Parameters and Circumstellar Interactions Ed. Paula Benaglia, Guillermo Bosch, & Cristina Cappa lar, rior Clouds dence 96 considerably the rates Z-ric binary hence tially essen ∼ serv & hence Z. arise that 1979). 2003), en cluded of need v The higher ten tion ha (Maeder easier-to-observ in around o main 2006), rotation atically other from ev jury The vious p v eal ear undisplaced en erestimate t v Meynet WR/O, the In The Ho The As e previous ed early and the mo of h a is tain in mass-loss tially more to in an binary to not of this all w factor, w . massiv latest of regions, the of initial tro factor WR whic due Z. still dels in (MCs), ork O ev single 1980 b WR main ha extension b This original more ∼ & (Maeder e the b y the It WR duction 1980’s, er, companions stellar v w 2005, e serious 1994). W rerun, binary all h to out + Meynet e factors (e.g. also b a so mo ev e binary inconsistencies and of C/WN y WR in to efore of whic seemed observ b seemed after massiv O goal absorption , the clumping. (Bouret stars binary olution allo een rates compared strongly e, in a 2. dels, it regions 10+, examine frequency another predicted sustained factor concept w with mo St-Louis strong A h stars of of this than OBSER w wing WR fr & of ∼ as seriously p 1995, t 2008). as ed action to frequency ma e Virpi’s and dels ossibly 1995, a realistic of the Meynet to this to stellar to stars (e.g. prop difficult uncertain exp factor reac w mass-loss y et stars for in 2–5 only of WR-progenitor dep resolv imp ould b stellar test RSG/BSG same lines more pla (Meynet to If V e rotation al. pro of ected that the in lo h w et WR rotation erties w A are Azzopardi due pla enden and confirmed, in y ortan w as the ranging o mo the TIONS ould the in the ∼ this the ject, v al. magnetic b er 2005). 2005; e that SMC against based y er-estimated regime time, the reduced 3 systematically the e exp winds. stars, dels the ed to a m Galaxy that, most outcome. WR Z, is Galaxy rates indep in metallicit t t 1988) n y increase pro clumping conceiv ected relativ binary factor & w out, um already w on at where curren SMC seemed F stars will the as it ere on up stage ullerton for ject Maeder lo Ho luminous while of b & Z, the of If enden w . compared this er w fields (finally) since O-stars rev stellar assumed to Breysac as w to mo In Magellanic w once O whic has e er since WR should as ed frequency t as of mass-loss ev effects Actually stemmed y n ealed included at (Maeder stars b a pro increase particu- Z delling. system- ma to the um in t er, a eliev dep ∼ arisen: appar- during h w essen- factor is man stars. again et lo 1997, func- of 40%, their b jects ha in y ould b pre- and w oth her an- ob- ap- the en- ers re- te- in- an al. b b ed v to to Z, er of MOFF y e e e , A Duffey the denote stars stars WNL (2003), WNL/Of w fat claimed w ered kno W there an and plete and 2001). W (Breysac stars tion al. lo that ing T al. Marraco other alogue with 23 of MCs of already real WNE et fide et the LMC, results T estor as as w). e C/W P al. subsequen 2001a,b). the al. As After During This O3f*-star wn sole first massiv eter 1991), the WR the found found (2003b). fain and W only in Virpi (WN1-5, in sp w and at 2003a,b; stars WR stars, completed for SMC/WR1, as of C/W (2001), O of as 1999, lab ectroscopic BA the clear This W 108 W first sole ter started Bartzak her w the + (1990; 2001), ). the its stars 134 the that as divided still 3 BA C/W C9 e elled in T99 b the O star the (WN6 as LMC, WN WR y O of W sp completed lik 1981; follo WR tly y A Bartzak results T99-69, led binaries star the referred in SMC, WR ear T excluding the F should ectrograph. indicating O last run the Most ely stars O in 1990’s of new estor, MNM). WR12 to o w os, kno although a p w t b ellmi star to SMC as star generic BA and yp the opulation that in y stars ed leading examine sole b m W stars run Azzopardi app study 2, completed fain a wn to eing Sc e, a of disco ultiple T99-4 os of (23 C/W b of ...., recen in whic MCs. in Sc later, to more hn BA 2004) grand y b eared the t although W in b CCDs b ter W study w relativ y these H-ric hild, the the y (Breysac then y a urr single) 11 t 11. as o v for O W T99-6, the F C/W yp h O Massey to ered more F disputed (due t Bartzak In should o all further CE, including o system w binary (mostly SMC SMC, WR I up had ellmi in BA and es stars binarit in h , Then ellmi total a & as CTIO fondly an in w & had ely 21 kno the WN5h dated O 2006 denoted fairly T99), to since Moffat, ere Lortet y extended LMC made 1998 a 47 1 little her, Breysac stars of no , stars short in (2004). wn b hea case, , w WN in os another in no b in Olsen, W PhD e y w WNL, the (Niemela all of ere een (Sc w 1 the b recall remo compilation w study the WN5h O); among vier 2002 then complete Azzopardi, y stars); (Bartzak BA eak-line) although m b W in effect found w w of in (1993), “pie” hn p in Of/WNL y then it Niemela, erroneously PhD ere eak F in C erio her theses: dome T99 LMC Massey v o IS urr the whic and fact the & 61 w tro all WN ed enjo ellmi (F (Massey mem (see as er-lined disco d. extinc- and P and on kno all 1979). o in duced in to et thesis WNE (Mof- et of LMC ark b com- ellmi h clear os MCs ying dur- WN no The star cat- and ona b the the an- the the b al., wn w al. all b 47 72 24 or v- er er et et of & e- & & w e e © 2008: Instituto de Astronomía, UNAM - Massive Stars: Fundamental Parameters and Circumstellar Interactions Ed. Paula Benaglia, Guillermo Bosch, & Cristina Cappa in for p pare ing findings in in b sp to WR eac 2–3 ∼ and WNL NIR in the CTIO LMC, among Th con t from these al. mogeneous effects b CI collision star in yp e erio ecomes W WN Group WN8,9 WR 1000) terv c ectroscopically I prep.). the omes us, T WR a h C/O R trary e 1998). I Ov The T BA Southern y able with MSO stars sp ak W o 5696 the ds binary o ears. W al ha stars erall, v original it = whic and and ectral en T99-69 C4 the er O C6 most b binary v of and in a (WW 8.0 results w difficult. to VERALL e elo 1. W 15/67 out The v emission. WR with 6/36 9/31 ould as 22 and 0/4 no these h Tw 24 arious Ro to data, LCO in previous Gal( C5 w a kp system W S/N mo w w imp a da C) Hemisphere: c to total W W the o-metre = P=200d, goals rest c = = ere to star he-lob e one = and frequency SSO Z app b 3.1 group, ys. (without de from C/W C4, 0.00 3

d=4 0.17 0.29 een effects, restrict ortan including in 0.22 at b timescales Here ∼ ) dense studies. observ . at 3. of W e ear BINAR do another of or 80 is The mostly Chile, WC/WO T ideas, due in reclassified e single, O3. O v this es the RESUL kp ABLE the t 144 an class o not, that in w it 19/126 16/102 b Australia, finding v LMC stars c not core as 3/24 reason 0/8 ed e ey erflo to the the der VL Previous with binary and pap is the Y WR see esp allo in ond SAA CASLEO mo r of strong telescop whether using and dep T = WR e 1 quite ranging ( = FREQUENCY TS 6 Huc w comparison in gar Br Z er = = ecially Stars in no W w optical, 0.00 (ESO, derate

WNL 0.13 am of end stars whic (e.g. O for 0.15 0.15 the ance using /2) will d C6 22, frequency including R(kp h BINARIES comp this less bien t SINF except in w remark WW of this (2001), on es LMC, h t whic ork summarize a in yp V stars from w for Chile) South 30 in resolution c)=6.5 the SMC study our t (1/1 of an 5/12 4/11 w ere massive v elling not whether 20–30 ONI/A e. C-pro high olving sho ere metallicit Argen Dor h wind-wind b Z to able for detection Ho . ev more presen 23 in observ . = a has Galactic ( = = w w Assum- Z used o This eren related Africa, orbital da 1.00) e degree w ed trends v

IN R136) 0.42 0.36 in ... duced are the times er com- ev /5) O tidal gone tina, that y it star t one ho- the the 9.5 THE (R er, an ed to in et in of y is is 6 . MA mates this O nated and in ing (2005). = 22 + cluded b NGC ha with try mec a for = the this for as companion ∼ of though The W is con there 2000 see FWHM). and not winds lines, 2007). of Galaxy whic to the shifted ing ha GELLANIC oth 200d v system C/W compatible v ving binary O 1.9, 0.27 initial uniformit and olv far tains Unfortunately Despite Among b e its is the the mother in hanism. the to w sho w h 3.0 e (non-eclipsing) binary binaries. mo close to for is termediate in ed e a compared 602c. b reduces tend unreliable, orbital 3.0, , stronger y could brigh in larger Br orbital O If as is significan y w the w a Another SMC , 5000 derate preparation hottest d they only in this ould p ev the large do in stars, probably some the This an 32; systems, erio W visual 14.9 n en galaxy its has the y es the to p ter whic Th um y normally O This CLOUDS ligh km/s. star photospheres erio one analysis, in with Br system. w only inclination. ds inclination. not if the short-p v ob success ha us again of b ould ranging little ariation P 4 d via deep to homogeneit than, it sp tly attempt t h ers LBV 31 probably vious , ds companions, v W . ev for and these W its app from Cygni all is e is opacit ectral see the this reliable their This the C/W w more Curiously en and are extreme are system C/W systemic lo ha esp effect three implies the as mass la erio ear ha phase co from t cated th original and Systems v b sp y w trend. shortest for a small, W in ecially omitted, e all will ma v efore ers oler y single us O t o using absorption 3 ectral O d brigh e to to yp C Ho higher This line during and CIV5808 of ( W on and b ratio LMC y star ). y relativ WW rendering τ ha still e of b the binaries, via b een within stars outer w b that , C mass the e = e R in is dealing that this the v e t width ev stars broadband allo coun primary the Vs necessary ob published e lo binaries has of differences a due with 1 blue kno red. C easily due er, M(W needs sp b systems w, Z, W viously rapid common-en in ely diluted t w the o ecause ws implies b la closer yp could ectral v wind loss. the terparts, wn b y ere C4 the with from to y as the erall edges stronger to among sup een ers. e p St-Louis short, the one they with O4)/M(O4V) presence detected. erio slo exp W op binaries the for SMC an in mass-loss has in wind) ergian attempted affected (Cro not the it to elsewhere, FWHM O4, in w sp and mass en The p reduction to subt emission- the Ho the ds ected and estimate an er estimat- olarime- (e.g. lo all is ectrum. the ev the that with cluster alw W y w fastest v w b y whic winds wther winds domi- up 16.6d olv et LMC elop yp inner SMC et t lead- e er ev tend esti- O R W of MC (Br not a Al- ex- 1.9 for Vs es, er, do al. ed 97 ys to Z, in in in of + = C P h a e © 2008: Instituto de Astronomía, UNAM - Massive Stars: Fundamental Parameters and Circumstellar Interactions Ed. Paula Benaglia, Guillermo Bosch, & Cristina Cappa FUV Br result ration) Boisv tical line, terest dep phase-dep compared mer, the WR9 the W 98 fortunately for F no hotter, eruption in also an lar p the Smith of orbit Of/WNLh a brigh easily = what Ko SMC/WR3 rio WN6. WR7), (WN3-5) p Blending strong significan terparts, alceta-Gon¸ eratures, onen similar-slop C4 yw CI their ds HD enigsb information All Among As masses 32, enden the (also data single sho I the a ter whic emission ert of binaries brigh I sho ts with lines y detectable. of for et is 4 to , 5696 Of observ 5980, with yielding although ws CI attempt the of than their winds W et as in ws t erger al. the t w going reclassified) h b enden and the b to I sp stars , H. whic ter are ell, y WW the C/W I primary the e strong for e al., 1994, is calv SMC they while do and similar (1996) P ecial 5696 the certain P e b ed whic W = sho their shorter ∼ zero-p lines wnstream still t it eha 11 & = collide h sequence the w in other on t from C = es C 80% O and lo to 0.3 with WR5, o ws w WW probably sup w and they 1.9 3.2 WNE WN Moreno These in prep.). the viour h w emission. stars 14.9d WW et the) binaries as emission , p ere ha extract system. single 3 er b terest (e.g. enhanced o is oin . whic and ergian of ev M eha dominated al. and orly v t degenerate , W p C a binaries, at WW WNE FUSE w stars e compressions in C discussed erio en V orbital t to in H WNE con o C4 stars systems of effects viour for in lo WN6 (2006) in than) h o, = effects, Ho deep 3.0d CIV binaries previous constrained. b coun (2008). is w con t C d t disfa sho the tain its Br w oth + underw M in er W excess Br − Stars w ma the None (and o O mo (St-Louis are ten V ev companion 4 CI e O7 the to w WW sp terparts, inclination, for sho 22 5802/12), of t MCs, in their v double y Sand 22. companion yp refer did H for del er, as ours I b are mo eeds binary t Br in all in although I v the y P th SMC, some c in Br es, (SMC/WR6 in en of It in C ery 5696, k-cone in (although catalogues. of derately WN3 of claim (In (th strongly us = more 22.) b all at Galactic t to the the parameters. the when consists the 1, 32 the elo their four based Br particular L 14.3d us an orbital w et eclipses. significan higher the all uhrs of ¨ SMC/WR5 whic 9 w Br and ell probably orbital In as CI in WN 22 formation other to otherwise pro flo are al. detail LBV-lik although their 20d, as binaries, the they w sp Galaxy the I con a 22 w. w strong, h on − I binary did phase- as (1997) Br viding some- WNE WNE ectra. coun- 19.3d ell of 2005; sepa- com- 6 form tem- 5696 stel- tain Un- and and and t for- to op- the p are All 31, tly w for in- an b fit as e- MOFF It y a o o e , A from in rio their trinsic disco the smaller sho data: tions CHO 64 = 7). P ( triguing 2.77d). cousins. et stars w sc sho al. O6, WN8, nition lute RSG, O, BA kno BA clude, presence the the 9.3 eclipse star + nifican lo from mass mo T ∼ as w heme = 1.2 200 ds the al. O6I (WN4o+O9:, dels. T99-129 T99-129 Of, ws w 2006; Among As Only F Sev wn Not system  sizes the v LMC units P rom 2.33d) and v alue. can certain progenitors Galactic b in in ered and BA 10 rather t in the I of Galaxy d) eral LBV, (2003a,b) WHEh) elo H WN6, 0.5 = Galactic for allo I-V: (O The fraction sub surprisingly mass-loss 34 X-ra is Both BA order three An T99-19 of massiv in 25 con the w of 0.1 4.2d). (see WNE WNE OGLE for ws & of erg/s) to the for Sp star ject and is T99-129 the 40d. turn their h tokhin last the Marc  tain ys to ydrogen mag WN7), the strange MC WN9-11), . an reduce ectroscopic 27.9 one stars BA coun F of SMC the 2 LMC, of In and e with suspicious, o BA eclipsing than of 9 in extragalctic P WR (WN4b+O5:, prop sample stars out ellmi With apparen time: significan T99-26 sp in henk M and stars, to and a data w outbursts con these binaries, =  T99-129 & terparts. , fron first ectra, recen ork in

the 2WNE understand WR5 the seems eO WR Chandra, 37.6d), to Cherepashc those osed line-emitting trast ligh 1.1 in hardest. o angular-momen for this our et ha t) i eO W com on guided b range has et time orbital t to eWNL the = (WN4b) tly binary v al. e observ t stars but M the are detailed is e t (in (in a system uniform the w 15 al. with lo bined in b 78 curv (WN3(h)a H, the (CHeB: of

single the broad four coun BA 2006). ere new WR e w Nine on a shell core the O b  20–40 unkno a  P in unlik WNE all in ha p eing compared T99-71 deep ations 1994). larger ho es. V444 most found, the (b h mixed erio star 2 terpart = the 2 v ev with are winds. uk with V444 large SMC w probably study LMC binary binaries, ◦ e H-burning eginning M regions H-burning lines, , 18.0d), olutionary sp e est the WNEb). d SMC, p wn used M 2007). The

tum the luminous their stars, basis (compared Cyg ectral ositiv eclipsing, fraction to at + semi-regular our

(WN4+O8:, all for eclipses bag, part sho The SMC Cyg, WNE origin. of (F , its O5V, m secondary masses These (WR5, to loss after to most (WN5 o with the Galactic wing man in the uc e BA sp of v ev ellmi F presen In CHeB: with b surv O-star arying recen o detec- h prob WNE CHB: ectral y SHB: abso- olv WN5 ellmi stars T99- from w MA- than This fact, defi- P (L WR y and lik sig- the p ell- in- in- in- all ed ey to et in of e- + 6, = X a e e t t © 2008: Instituto de Astronomía, UNAM - Massive Stars: Fundamental Parameters and Circumstellar Interactions Ed. Paula Benaglia, Guillermo Bosch, & Cristina Cappa This WNL-lik in ob binaries w vidual HeI o o Smith all > a3, w large ro coun w WN line to 3) binarit telescop tributed most tem, lines H LMC yield nary” and Sequence. with detection egory lo t b the stars, cally high the the w v ccur y ere e e w w erview o in ject b stark 1000 Moffat subt cen find F In Among These Among ha est I CHB optical. binary a5, e (only 158.8d formation systems terparts rom 6 found stars 4686 the of w , BA in cen significan quite the v WN most in category tral, y con while systems as NGC single e et lines, yp , the the b, that es, T99-92 km/s) con e) are tral reclassified within man winds. nor and phase, our imp al. es. trast WR as one (1989), are R stars c) (WNE frequency the within significan (BA are eigh the In stars LMC frequen latter trast Vs t 3603, also none WN5h binaries, with y with runa stars ortan at rev A w there (1996) kno This generally . the pro t six ha signature o approac O/IR short-p cases T99-119 t sho 41 with has the app Note sometimes scatter), all eal other with w ving from using generally w subgroup since wn) 3.3 cess the that certain of com P all wing t in WNL can latter ere tly a sho sub ear w the WN5-7 stars b in all y t, . the = b whic sp among system the een ould that, broader-line WN8-11 p erio bined ecause among prop if the WNL among as in found h outshine ws the order stars traditional the classes, driv erio ectroscopic the to presence 92.2d = a the there 6 the stars an of noted case, probably returned R136 binaries, MC h d R145, core ha evidence ∼ WNL imply erties. as narro ev BA ds e brigh non should 2 t binaries. broad 60 accelerating fall LMC Stars WNE most v with yp WR to without en to the WNL WN4-7 of for in e the (BA T99 W sample. w studied it of a1, es, in although km/s relativ gain some on WN10-11 the b ere w the in WN6(h)). ter or C stars all strong that e is BINARIES the er 10 a T99-99, Esp WNL) tec v systems all luminous while to emission easily as a2, stars or results catalogue the not certain alue stars, preliminary for stars range an 3 their the than strong a hottest hniques subt the Galactic are binaries. a redshift near ecially an ely WN6ha (R136 y homogeneous a3, sp WN This of “p . short-p result WNE y for is no winds wind. ectroscopi- allo some ev are WNE high sho significan Curiously yp ossible extremely the 2–5d, a5, the WNL for difficult WN5h:a) the also (FWHM emission One binaries, enly the binaries binaries app es. lines w of w (WN2- for a1, still at in IN this of R136, single stars, stars, (with LMC Main (run- clone erio their indi- Tw v that that nar- WR ears The w cat- sys- and 2 dis- the the the ery (or a2, THE bi- a m in in y is d y o t . , MA 126 and-add, in ing b star ration), WR20a function more the (Uso mary trum, ing ren the  to also the R144 p band of p ha Based in ma their with b 119 these erage kno panions. stars BA L considerable on ∼ R136: Dor, more ∼ 55 a GELLANIC w est erio eatibilit e X 1200 650 v con Moffat a EW 30 higher y an (R a tly T99-116 Among Tw Still e wn in either y?) companion, masses v individual sho (WN6(h)), in  v ∼ K(O) b little d stronger erage, V ti-phase sho p single WN6ha although compact vincingly km/s blended steeply ma M e strength from 1992). 10 so o on in R145 olarization km/s 32 is R144 (158.8d), ws WR ∼ R close

comparing with 35 as w brigh y y of w Vs: 140 v the on that our (1989) . WN6ha if and strong ery e v to also no detected b cf. with erg/s, exp R and alue ∼ an couterparts. a Ho the devised ecome star for scatter) CLOUDS Both V = binaries v pro km/s). BA 400 83 than curren pro comp t lines with y significan stars) large. erage led WN 280 around 55 w sp see ected far b only amplitude WNL excess most BA most -101/102 WN5-6 at T99-12 FWHM ev and cess v  e WW ectra elliptical an data, e comp km/s  of the to the er, a km/s onen on T99-118 with maxim all the from ev 5 stars t this. LMC ywhere, for a clearly these ∼ 21 binary previously for from massiv of R lik minim C with en and companion a tec stars with p due 0.5 the V t v onen t in WNE w t kno eriastron w excess ely stars, v M (the for erage, 1/r WN2-4 for (HeI m difference in to e hnique erifying tend the o data (but F Finally WN um

stars mag 82 to K(O). uc or accreting, (e find LMC adiabatic wn an NGC apparen um sin t e . stand WN9-11 (WN6h), stand the the but (r h and stronger binary I in stars star R145 cen  line-depth = to in This probably com to 3 stars, 4686) O-t although higher. primary that fain is ha unpublished masses the LMC) , of exp 5 stars. curren i HeI ∼ 0.7) tral WN passage on 3603/A1 W ha this R145 w v yp hotter the out. = bined 2400 than out, M e shift-and-add ter in eighed, tly e w Galactic mak v presence. ected R145 an I e L L ranging e

compact e 0.25 WW stars found 4686, dense binary case FWHM stars, the X X result. orbital , star, y and tly faster in w W Binary single These M WNL km/s b es only orbit, = or giv the after ∼ app with ere trinsically somewhat oth WN e C is brigh in frame with lac with sin the 1–2 surpass- are through en BA BA the increas- mo , a a scatter hotter, ears cluster unable broad- binary theory on one ks winds R145, 3 in stars, (with those while shift- With R145 sepa- sp long- com- stars stars stars clear T99- T99- from as ving 10 WN WR cur- test pri- 114 i R a ec- re- 30 99 to v- 33 of of of = V a . © 2008: Instituto de Astronomía, UNAM - Massive Stars: Fundamental Parameters and Circumstellar Interactions Ed. Paula Benaglia, Guillermo Bosch, & Cristina Cappa ing lost burning pro at siv WR+O that that far An the phase, app lution not Azzopardi, WR+O summarized 10 and from phase p v lo that 100 erg/s, loss alues onen w − e tokhin, lo Rep., vide • Of • • • • • • • • The neglected) 4 ear w follo enhance for rate less blank stars. w the RLOF the eak M sp WN5-7ha More Significan Impro Detailed Wind-wind Detection The V t. er whic dep of particular with in ery its

ectral to most wing absolute binaries Main of systems er 51, 4. Z; of presence v p This T* /yr eting. enden I. olving olarization M., binary h p v their winds 3 SUMMAR this short w v ary 486 is significan ossible I., is as and its ed ork 10 deriv imp follo Sequence fits companions & not v not & studies t follo − alue t, . and probabilit ma with initial stars with amoun Breysac 4 w L geometric on ortan rapid Cherepashc imp w-up than p REFERENCES of increasing collision ed frequency for ere imp esp M y for erio binary 5. ws: quan the a is

b b t p ortance data Y ecially am R144, e FUTURE probably are /yr ortan y t massiv the erio angular d, mass-loss their of comparable ts studies: expansion and her, findings related OF brigh Cro bien tification of y eclipsing ev for WR ds nature, little in for constrain effects of t H h wther J. are HIGHLIGHTS olv cousins high, where at t of uk, e in test in the the in are b 1979, R145 metallicit star momen star ed ecoming p to lik the WR formed most of ev A. m eriastron. from binary brigh seen stars although ely suc of nor & y olv (i.e. during this are they to in due range WR M. A&A, lead at ts. view the stars Dessart h ed WR the a tum the in the the ter study 2007, higher in strongest stars via to binary y a systems. (mostly did systems WNE p off , to most 2-3 R136. 75, WR system. WR ost-LBV) w stars the increased clumping v do and implying W could CE alue ould a Astron. the not ha can w es (1998) 120 e mass- Z. com- eeks. LBV stars mas- star. do ha note ving ev and not 1.5 so- al- H- b b b to v- es o- in MOFF e e e A Bartzak Meynet, Massey F Bouret, F Massey Cro Marc Massey Ko Breysac Niemela, Moffat, Moffat, F F F Breysac Smith, Cro St-Louis, L v T Uso Maeder, St-Louis, V T an o ullerton, o o alceta-Gon¸ uhrs, estor, ¨ an ellmi, ellmi, ellmi, enigsb MNRAS, 115, A&A, 2001, 137, 1994, MNRAS, ApJ, 301 ApJ, A&A, V. MNRAS, 33, tard, Rob 1998, 426 wther, wther, v, b der henk ev V. 2006, , , , 116 S. eren, ert, L. G., her, her, os, A. J.-C., Huc A. 1265 117 P P C. P C., C., A., G., 637, 348, J. erger, AJ, ApJ, Ap&SSL, V. V. N., ., N., o, 1997, ., 447, 369, ., A. P P ...... F., F. P Olsen, Sc F. M. 2004, C. & calv . . J., h 2003b, 2001b, 1991, 2003, 2008, 2005, S. J. De MNRAS, 1992, Moffat, Moffat, & ., S., & D., Moffat, 324, 338, 281, t, A. A., Moffat, 121, hild, 1025 232 J. W., Lanz, Duffey Shara, Moffat, J., 1988, 667 544 1981, V., 422, 2005, Meynet, Azzopardi, Maeder, G., K. P Seggewiss, es, Gioia-East 1989, 2007, ASP & v A&A, A&A, A&A, RevMexAA A&A, 18 360 163 Niemela, K. an ApJ, 1050 Moffat, Massa, A. H., & D., MNRAS, MNRAS, 232 810 Dessart, T., A. A. , ApJ, A&AS, ApJ, A. A. Moreno, , A. Rensb 2001, M. A. 371, ApJ, ARA&A, A. & 109, Abraham, F. F. G. 389, A. & F. G., 416, F. 244, 404, 440, Lortet, S. F. M., 330, M., D. A. Hillier, 628, w J., J., J., W., 1997, 1994, 1295 J., 504 & V. NewA 2001, ergen, 347, o L. J., 43, 635 291 338, 324, o L9 975 1041 F. L., & & E. Drissen, P & & (SC), d, Marc 286 S., 953 1998, & ark & 203 J., 45, Marc Guerrero, T 2008, M.-C. 373 Moffat, A&A, A&A, & K., Z., ApJ, D. 1025 33 Moffat, estor, Niemela, Rev., & er, W., & henk 177 Prinja, 33, J. & MNRAS, Marraco, henk & J. Ko RexMexAA L., 1993, 550, 2005, & 321, 287, Jatenco-P G. 42 W. W o, 45, enigsb A. A. Bastien, o, De aterhouse, M. 1999, S. V. 2003, R. 713 135 465 803 F. S. F. A&A, A&A, V., Lo A. S. erger, 296, K. H. V. J. J. A&AS, ore, & P 2001a, 2003a, ereira, (SC), 2001, 1990, 2006, 2006, 1996, P ASP 438, 280, 622 Pit- ., G. C. E. & , © 2008: Instituto de Astronomía, UNAM - Massive Stars: Fundamental Parameters and Circumstellar Interactions Ed. Paula Benaglia, Guillermo Bosch, & Cristina Cappa H-burning. There reac N. WR hardtime M. A. A. line G. A. so? (e.g. the T ideal massiv A. on pre-main In Br R136 P. ha A. A. and o A. lik sytems. (an A. A. stronger than more N. con A. stars wind-wind G. N. to compatible H. stars input v eff erflo v e WN6ha 22 emphasize Massey Moffat Z. Moffat Moffat Moffat Zinne Moffat tiphase Ko Moffat Moffat Walb R tain Walb Mae Smith Moffat e Moffat Cor cen h y and profiles? WN) star. auw emission but the our stages whose in ev core, or enigsb suc the w are e tral c der olv suc or orn NGC orn than In WR significan cker than is h wind these excen sequence - b - an end man - and ------ed - elieving - collision h stars, unimp - as for Concerning WR20a, while hot - I with The If er The This Y Sure, to W wind W - - Bac Be 9 The stars am T - et descendan - the 3603 ger that tidal I the normal ell, CI e lines y of or tric do on binary found w (in The I stars agree reclassified they k careful clues ere qualit am v I not y ma lines colliding there the ortan colliding most - I c but the tly ery Andr feature observ , to the are haracteristics the system fitting in W effects, that 5696 that short if zone h for y impressed sure in these ydrogen e them all brigh main with lion’s the Of that high y b companions, y y of ∼ Galaxy). t, distinction prop ´ e, are luminous ou ou the e instance, the ts with NGC of ed seem are 2 NIV is rather ho stars due that y p w Galaxy) (Brandl of ha is ter reduce winds wind ou these if Myr our erio Nathan. a v to as debate masses sequence a w cluster. osed some share b ery stronger suc v another few w eha small selectiv to 4058 ric 3603 e do tell there, fit (b to all e and d “disco that WR to h, old. than This high h con y accept small stars viour mak that binaries O2-3 some y tigh ha w theory these of in me! and the ou 1 et still b tak the ell ab and o of and stationary v tribution, n et y w these mag remo There BINARIES LH10, w e e e um without t al. v example our in out mass is form than w p e e in 80–120 are e ery mass n not v star them massiv WNLha emission The H of of eriastron een WNL NV the the their um R136 ery probably should the b 1999) the for core ving in VL er the WNLha m in the sp extreme necessarily b the the W are 4603/19 (on ust the mo these lines fact high termediate winds ers. the loss T/Sinfoni ectra” statistics! lo the WN WN-lik olf-Ra e emission stars are shedding M burning of H-ric of excess ok for and del. WR strongest 100 eclipsing ha b a core stars case

that line v e passages course). rates that masses. adiabatic this compatible only t IN erage) a v system. visual) stars w co-rotating. of that e (actually the Of h y preclude M bit stars? DISCUSSION o fall of e et seen in of are THE the the outer phenomenon.

emission N are categories emission stars 1 but b lines NGC data size lik b stars m O-t NGC An y on or T ric O2-3 Myr i.e. et binaries absorption strigh individual LBVs uc on These e it least in should a w h. Whatev yw more In O2–O3 yp this case. la WR MA of h y at that een using factor do in WN5-7ha) 346, an the – y with 3603). W old. a e addition, stars, of the sho ers y constan in t y (or the in Do GELLANIC to not e sp category , seem O stars. are highly up their is v refined lead called b further w the T the It so ectra, ariable cen the extreme HeI the e stars er stars r14 not ed of y the quite rev from comp and giving ou asso lines do that The tral they R136 to most to 10 I WN for t mass O eal and es at 100–150 4686 mixed. the these see are R and b o so ciated study I the and stars out and difficult V onen the an 1 profile ca ccur – eing all) not these an b are luminosit us system Pismis an at LBV Myr the cluster luminous eliev that vit in in LBVs WN6ha O y in (Massey “Of they brigh CLOUDS y in susceptible ts. another the app y the b called, new the at lik line-driv 30 star with p evidence eing M R145 e WNL pushed age w addition should ossible scenario e stars all Dor, to that ear end

as frame are test 24 most of – there that. short can y increasing range. refers mak probably main Z classification alw , Smith WNLha that they to et of sensitiv (30 clue stars whic on NGC the suggests cluster en pass b bac massiv con a the of e al are of require p e to ys has steroids” Dor y sequence winds. erio do from only similarly ou ha h that the considered 2004). k rotational tribution et shouldn’t wind-wind 3603 the main stars to driv v b e not, no mid d sa stars O2-3 e y 158 e al. line O to a to that their the massiv distinction y emission the MS an confirmed es (classical) and star, sequence. sp By that actually are An that (justified or NGC – da y emission; or a stars, are most ectral massiv com just they stars, late y additional of ys strong sp T the v ∼ b (sub)gian (p e but w ariabilit rumpler clue collision the e ectra 3603, probably narro bined binaries ere 1 binary) erhaps v lines stages tak massiv w migh ery i.e t Myr forms e w I yp dep a b He-burning Ro wh when Sometimes called y e wind. WNLs w en et it at w in e luminous based didn’t ould c winds I w that t y y endence app old. he as 16 ts. feature effects. w similar ligh of een e ha energy binary b is in in in seems eak e more stars stars w v that lob core WR ears this 101 lik the the the the tly e are are ell. Of on er in of a e e .