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

Villa, A. M.; Trinidad, M. A.; de la Fuente, E.; Rodríguez-Esnard, T. PROPER MOTIONS OF L1551 IRS 5 BINARY SYSTEM USING 7 MM VLA OBSERVATIONS Revista Mexicana de Astronomía y Astrofísica, vol. 53, núm. 2, octubre, 2017, pp. 525- 531 Instituto de Astronomía Distrito Federal, México

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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 © Copyright 2017: Instituto de Astronomía, Universidad Nacional Autónoma de México n fteeris vltoaysae fteforma- the of stages evolutionary earliest understand- the our of improve ing to molecu- helped and have outflows objects the lar Herbig-Haro example, For pro- of physical motions formation. various proper study of regions to in tool cesses powerful a be to multiples. prob- or serious binaries really are a iso- most is of since still This that lem, is is stars. as systems low-mass modeled lated stellar succesfully multiple being from and far forma- binary the of of observa- tion understanding been our has and However, (1987) theoretically tionally. al. both et tested accre- Shu The by successfully proposed studied. model well tion been has clouds molecular eit eiaad srnmı Astrof´ısica Astronom´ıa y de Mexicana Revista o M´exico.to, M´exico. RPRMTOSO 15 R IAYSSE SN MVLA MM 7 USING SYSTEM BINARY 5 IRS L1551 OF MOTIONS PROPER 1 2 h eemnto fpoe oin a proven has motions proper of determination The within stars low-mass isolated of formation The eatmnod srnmı,Uiesddd Guanajua- de Astronom´ıa, Universidad de Departamento eatmnod iia nvria eGuadalajara, de Universidad Fisica, de Departamento e Words: Key 15 R e1.7 tot de masa 5 una estimamos IRS relativo L1551 propio movimiento al base en siae oa asfrteL51IS5bnr ytmo 1.7 of system binary 5 IRS L1551 the for mass total a estimated e itm iai,lscae o leeo e2. a yr mas 25.1 de alrededor son cuales alrededor los de tiempo binario, propio de sistema movimientos intervalo los un del cubriendo multi-´epoca estimamos cinc B, datos observaciones, la de estos con conjuntos seis uno del usaron y mm Se 7 A de . onda 5 de longitud IRS una L1551 a Array) Large (Very Grande Muy . 246 of period in eeue,cvrn iesa faot1 er.Wt t With yr mas years. motions 25.1 proper 15 s relative about about binary and are wit of 5 absolute which one span the IRS and time estimated L1551 we configuration a the data, covering A for used, the made were with mm tion, five observations, 7 of of wavelength sets a at archive osdrnouadsacad 4 c . a yr mas 4.2 y pc) 140 de distancia una considerando n . a yr mas 4.2 and .INTRODUCTION 1. .M Villa M. A. nlzmsosrainsd larslc´naglrdla del resoluci´on angular alta de observaciones Analizamos eaaye ihaglrrslto bevtoso h Ver the of observations resolution angular high analyzed We iul(15 R )—sas formation ISM stars: — — matter 5) circumstellar IRS — (L1551 general vidual binaries: — 1 − .A Trinidad A. M. , 1 eevdMy2 07 cetdAgs 42017 14 August accepted 2017; 22 May Received epciey ial,bsdo h eaiepoe motio proper relative the on based Finally, respectively. , M ⊙ nprooobtlo 4 a˜nos. 246 of orbital periodo un y − OBSERVATIONS 1 ( 1 , ≈ .d aFuente la de E. , 53 ABSTRACT RESUMEN 16 2–3 (2017) 525–531 , . ms km 7 sn bevtosa m orıuze l (1998) al. Rodr´ıguez et mm, 7 radio particular, at at In observations system 1985). using binary Cohen a Moreover, & as (Bieging detected wavelengths is prototype. 5 (YSO) IRS L1551 object stellar young hc stebiheto h lu (40 cloud the of source, IRS5 brightest the the ac- embedded very Thad- is is a which L1551 & hosts In Ungerechts and 1987). (e.g. pc deus region 140 star-forming about of tive distance a at its Rodr´ıguez understand 2004). (e.g. to thus process and formation sys- environment binary its and the the tem between us study interaction help to the could which understand us components, allows both systems mo- of star kinematics proper the binary relative particular, of of and In order tions absolute the . of on per determination are milli-arcseconds stars this few near proper In a show for also 2014). which, protostars al. that motions, et known Frank is (e.g. it regard, stars single of tion − 1 h akcodLns15 L51 slocated is (L1551) 1551 Lynds cloud dark The osdrn itneo 4 pc) 140 of distance a considering − 2 1 n .Rodr´ıguez-Esnard T. and , epciaet.Finalmente, respectivamente. , bouo relativos y absolutos s o aconfiguraci´on la con o ftebnr system, binary the of ldlsseabinario sistema del al − h configura- B the h 1 M ciodlArreglo del rchivo eemulti- hese ( e1 a˜nos. Con 15 de ⊙ ≈ itm binario sistema ag Array Large y n norbital an and 16 se.Six ystem. . ms km 7 indi- : ,we n, 2 − 1 L ⊙ n a and ) 525 © Copyright 2017: Instituto de Astronomía, Universidad Nacional Autónoma de México rprmtoso hssse sn L observa- 2+0 VLA and, using cm 2 system at this tions estimated of (2016) al. motions binary et Lim proper Lim 5 (2003), and IRS al. (2006) Takakuwa L1551 Rodr´ıguez et & the example, For of direction system. the in formed 1980). al. source et driving (Snell the outflow is molecular 5 a IRS of L1551 that known also is ( separated 0.3” are about which by disks, two from protoplanetary stems compact emission continuum the that showed 526 prtdudrcoeaieareetb soitdUniver- Associated Inc. by sities, agreement cooperative under operated iey oti icsinadsummary. and discussion a contain tively, results. observational the present rmteVAacieo h ainlRdoAs- Radio National the taken of were (NRAO) archive system Observatory tronomy binary VLA 5 the IRS from L1551 the of tions iaeo h oa aso h ytmado its of and system the es- of good mass a total allow period. and the are date, of system to timate 5 up IRS accurate L1551 most proper the the relative The for calculated system. binary motions of 5 disks IRS circumstellar and L1551 the absolute the of the determine motions a to proper covering years relative mm 15 7 of at span emission time continuum the of tions is motions, proper their determine circumstellar mm. to 7 the so of and emission disks, to continuum wavelength the VLA appropriate the study of most emission the dust the the jets, than from radio compact Since comes more it disk and extended disks. circumstellar grains, of the the that of with also emission but associated 5, jets IRS thermal L1551 circumstel- of the of disks emission lar the emission, only contribu- dust not from traces wave- free-free which contribution important a minimal an a at has and disks tion cm 2 circumstellar of the length of emission the uselrdsso 11 R ,ol aast with sets data only cir- 5, two IRS addi- the L1515 In of for disks positions mm. cumstellar reliable 7 determine of to wavelength and tion, A a the se- at we with configuration emission, out B free-free carried of observations 5 only IRS lected L1551 circumstel- of compact and disks the 5 lar to IRS contribution L151 the the avoid to of components two the spatially ecieteVAacieosrain;in observations; archive VLA the describe .TEVAACIEDT:OBSERVATIONS DATA: ARCHIVE VLA THE 2. 3 rprmto tde aearaybe per- been already have studies motion Proper l bevtosue oetmt h rprmo- proper the estimate to used observations All hsppri raie sflos in follows: as organized is paper This observa- VLA of sets six analyze we paper this In ROi aiiyo h ainlSineFoundation Science National the of facility a is NRAO N AAREDUCTION DATA AND ≈ 0A tadsac f10p) It pc). 140 of distance a at AU 40 . m epciey However, respectively. cm, 7 3 nodrt separate to order In . § n ,respec- 5, and 4 § § we 2 we 3 IL TAL. ET VILLA le asinfi oteiae(e al 2). Table (see image ap- the which to CASA, fit were of Gaussian 5 a IMFIT IRS plies task circum- L1515 the system both with binary of obtained the positions of The disks maps 1. stellar continuum Table multiepoch in the given synthe- of are the size and beam calibrator the sized phase The of CLEAN. CASA images con- the task of radio cleaned parameters ROBUST best several procured using the field we obtain maps, to tinuum order standard In following and Soft- techniques. Astronomy (CASA) Common Applications software ware the 1. Table using in aged given is sets data MHz. six 100 the of right on bandwidth and Information a All left with both November. polarization in circular 2012 about to performed of March were span 1997 observations time from a years, covering archive, 15 configuration B VLA the the of sets one in and data configuration five A found the of we considerations, these Under eeotie ihtodffrn hs calibrators, phase different observations two selected with the Since obtained 1). were Table see 2, 6; (Sets remain- and calibrator the 5 phase while 0431+175 the 4), used and three same 2 ing 0431+206 1, the the (Sets used using calibrator sets phase out data three carried calibrator; not phase the were in found archive Un- epochs VLA have time. observation over six components position the two fortunately, spatial the their that this shifted From evident clearly years. is 15 it about of figure, span shows time compo- of a south over 2 and position nents) (north Figure projected disks circumstellar the two of the seen. evolution com- is temporal both the of disks position circumstellar spatial the pact shown where is 1, 2003.73) Figure (epoch in system binary 5 IRS L1551 ucetsniiiywr eetd(rms selected were sensitivity sufficient e pc rjc hs airtrBa Size Beam Calibrator Phase Project Epoch Set 970 R2703+0 0.15 0431+206 AR0277 1997.03 1 999 T2503+0 0.16 0431+206 AT0235 1999.99 2 020 T2903+7 0.06 0431+175 AT0269 2002.09 3 037 C6503+0 0.06 0431+206 AC0675 2003.76 4 048 C7303+7 0.05 0431+175 AC0743 2004.89 5 029 2-9 41150.04 0431+175 12B-091 2012.90 6 BEVTOSFO H L ARCHIVE VLA THE FROM OBSERVATIONS l aast eeeie,clbae n im- and calibrated edited, were sets data All neapeo mcniummpo the of map continuum mm 7 a of example An .RSLSADDISCUSSION AND RESULTS 3. AL 1 TABLE T7MM 7 AT J00 (arsec) (J2000) ≤ × × × × × × .9 -1.4 0.09; .2 -68.8 0.12; .4 -21.1 0.04; .5 -20.7 0.05; .5 40.8 0.05; .4 -14.5 0.04; 0 . mJy). 2 © Copyright 2017: Instituto de Astronomía, Universidad Nacional Autónoma de México emsz s0 is size beam 037.Cnor r 4 3 ,4 ,7 ,1,1 n 18 and 15 epoch 12, at 9, 7, mm, 5, 7 beam 4, at mJy 3, system 0.11 -3, times -4, binary are 5 Contours disk IRS cicumstellar 2003.73. L1551 the of the map of contour Continuum 1. Fig. l aast a eue ocluaerltv proper However, relative calculate 5. to used IRS be motions. L1551 can sets of data components all simul- two motions sets proper the data absolute of all the use determine to to advisable taneously be not would it 029 ot 417 04.794 04.930 34.1576 04.946 34.1515 North 2012.90 04.976 34.1527 North 2004.89 04.997 34.1494 North 2003.76 05.075 34.1422 North 2002.09 34.1411 North 1999.99 North 1997.03 pc opnn ..(20)Dc (J2000) Dec. (J2000) R.A. Component Epoch OIINO H W OPNNSOF COMPONENTS TWO THE OF POSITION ot 410 04.439 04.594 34.1602 04.609 34.1526 South 04.641 34.1534 South 04.682 34.1498 South 04.748 34.1418 South 34.1395 South South . 06 × 0 . 15 R 5 IRS L1551 5(otmlf corner). left (bottom 05 − AL 2 TABLE 1 h m os ftemp The map. the of noise rms the , 04 h 31 m RPRMTOSI 15 R 527 5 IRS L1551 IN MOTIONS PROPER 18 ◦ 08 ′ µ n aast ihtepaeclbao 0431+206 calibrator abso- phase us- The system, the 5 with IRS subset. sets L1551 each data the of ing for motion time proper 5 IRS lute of L1551 function of components per- ab- as both measured also of the we positions to fit solute calibrator, least-squares same linear a the formed with out carried (2003). al. Rodr´ıguez et by obtained were 4 cipisavlct ntepaeo h k of sky the of plane the in velocity ≈ a implies pc 140 oino h 15 R iaysse so the of is proper system absolute yr binary mas in 5 The 25.1 shown IRS of are L1551 order 3). the fits Table of these also motion of (see the results using 3 time The Figure of function epochs. a linear six positions as a components absolute both made measured of the we to calibrators), fit phase uncer- least-squares the positional this Under of the tainty small. considering very (and is calibrators VLA) assumption phase the the by of observed assum- error by (as sets positional data the all proper that using absolute ing 5 rough IRS very L1551 a for Therefore, estimate motion to de- ratio. try are span signal-to-noise can system we large time binary a long the with a of tected cover components sets both sets. abso- data data and the all six using for the system are value we the However, reliable of mm, motion 7 a at proper calculate 5 lute IRS to L1551 able of sets not data six the for the respectively. indicate component, squares south and and over north Circles system the years. of binary cir- 15 position 5 of compact IRS span the time L1551 of a of the time) of position and disks of cumstellar evolution ascension, temporal (right Plot the 2. Fig. ′ DEC(J2000) +18◦08 δ 4.4 4.6 4.8 5.0 5.2 34.17 16 = nodrt nlz ahsbe fobservations of subset each analyze to order In ic w ieetpaeclbaoswr used were calibrators phase different two Since . ms km 7 − 18 . 2 3.1 − ± 34.16 1 eysmlraslt rprmotions proper absolute similar Very . bouePoe Motions Proper Absolute . 0 . a yr mas 6 AJ00 04 RA(J2000) − 1 34.15 ( µ − α 1 h 31 ,wiha itneof distance a at which ), +17 = m 34.14 . 4 ± 4 . a yr mas 0 34.13 − 1998 2000 2002 2004 2006 2008 2010 2012 1

, Time (years) © Copyright 2017: Instituto de Astronomía, Universidad Nacional Autónoma de México BOUEPOE OIN FL51IS5 IRS L1551 OF MOTIONS PROPER ABSOLUTE oi n ahdlnsrpeettelatsursfis h c The fits. least-squares the represent lines dashed and Solid St ,2ad4,i fteodro 39msyr mas 33.9 of order the of is 4), and 2 1, (Sets ascension right the of observ t evolution are both temporal include circles a The bars Blue circles) (error calibrator). 0431+175 (full sets. calibrator north data phase the six the with all of using motions system proper binary Absolute 3. Fig. 528 seFgr ) mligavlct ntepaeof plane the in of velocity a sky implying the 4), Figure (see naslt rprmto faot2. a yr mas 21.7 about of motion proper absolute an ( svr ls ota siae sn l aasets. data all using values estimated both that of to mean close each very the for is different, and motion slightly 5 proper is estimated 2, subset the (Sets observations Although 0431+175 the calibrator 6). using phase system the binary with 5 IRS L1551 ugop1Nrh+25.2 North 1 Subgroup ugop2Nrh+10.8 North 2 Subgroup ≈

l aaNrh+15.5 North data All h m

14 AR (J2000) 04 31 aaComponent Data . ms km 5 34.13 34.14 34.15 34.16 34.17 ≈ 9520 0521 2015 2010 2005 2000 1995 − 1 22 e iue5 setmtdfrthe for estimated is 5) Figure see ; ot +19.2 South ot +30.0 South ot +13.7 South . ms km 6 AL 3 TABLE − Time (years) msyr (mas 1 nteohrhand, other the On . µ α ± ± ± ± ± ± − 3.9 3.7 1.0 1.0 1.0 1.0 1 msyr (mas ) − − − − − − 19 17 20 18 18 16 ...... µ 2 1 6 8 8 9 δ ± ± ± ± ± ± IL TAL. ET VILLA − a) 0 0 2 2 2 2 1 ...... − − 4 8 0 0 0 0 ) 1 1 n elntosi hw npnl ( panels in shown is and s epstoa netit ftetre oreadtephase the and source target the of uncertainty positional he lrfiuecnb iwdonline. viewed be can figure olor toswt h hs airtr03+0 n e circles red and 0431+206 calibrator phase the with ations dsuh(mt ice)cmoet fteL51IS5 IRS L1551 the of components circles) (empty south nd rjce eaain n h oiinage be- angles position measured the the to and fit separations least-squares linear projected a made we is angle position the while time, decreasing. be- with which separation increasing observed, clearly projected is is the components about two in of the change span tween A time as a components, years. over separa- angle, 15 south position spatial and the the as north well of the time figure between over This tion change evident. are the the system shows of binary disks 5 circumstellar IRS two relative L1515 the the where of 6, three- motions Figure in proper A shown is an- time) 5. and position IRS gle separation, L1551 (projected system plot compo- binary dimensional south the and of north the nents the measured between we angle Then, position and epoch. separation observation ascension each projected (right for posi- its component calculated the and south measured declination) we the then of observa- and tion sys- mm reference the 7 of as component north of tem) the intense of sets most position (the spatial data the component sys- took six we binary First, all 5 tions. used IRS L1551 we the tem, of motions proper tive Dec (J2000) + 18° 08′ nodrt aclt h eaiepoe motions, proper relative the calculate to order In rela- the of study detailed a perform to order In 4.4 4.6 4.8 5.0 5.2 9520 0521 2015 2010 2005 2000 1995 3.2 eaiePoe Motions Proper Relative . Time (years) a n ( and ) b ,respectively. ), b) © Copyright 2017: Instituto de Astronomía, Universidad Nacional Autónoma de México iaysse o ugop1(aaSt ,2ad4.Tetempora The 4). and a 2 circles) ( 1, panels (full Sets in north (Data shown 1 the is Subgroup of for motions system proper binary Absolute 4. Fig. nFgr seas al ) rmtefiswe fits a the at From separating shown is are 2 4). component of fits Table south rate these the also of that (see found results 7 using The Figure time, in of sets. function data as all components both tween ewe h w opnnsi hniga rate a at changing is of components two the between h m h m − AR (J2000) 04 31 AR (J2000) 04 31 0 . 6 ± .

2 34.13 34.14 34.15 34.16 34.17 34.13 34.14 34.15 34.16 34.17 0 ± . ereyr degree 1 9520 0521 2015 2010 2005 2000 1995 2015 2010 2005 2000 1995 0 . a yr mas 6 a n ( and ) − − i.5 aea iue4frSbru Dt es3 n 6). and 5 3, Sets (Data 2 Subgroup for 4 Figure as Same 5. Fig. 1 1 b Time (years) Time (years) sn h i aasets data six the Using . hl h oiinangle position the while , ,rsetvl.Sldaddse ie ersn h least the represent lines dashed and Solid respectively. ), RPRMTOSI 15 R 529 5 IRS L1551 IN MOTIONS PROPER a) a) dsuh(mt ice)cmoet fteL51IS5 IRS L1551 the of components circles) (empty south nd rto n oiinagebtentenrhand north 335 the about between of sep- components angle projected south span position average an time and estimated a aration we considering years, and 15 observations of mm 7 of h t,w acltdarltv rprmto for motion proper relative from a obtained calculated those we and fits, values the 180 these and Using pc) 140 tively. of distance a assuming Dec (J2000) + 18° 08′ Dec (J2000) + 18° 08′

4.4 4.6 4.8 5.0 5.2 declinations and ascensions right the of evolution l 4.4 4.6 4.8 5.0 5.2 9520 0521 2015 2010 2005 2000 1995 9520 0521 2015 2010 2005 2000 1995 sursfits. -squares Time (years) Time (years) ± a (47 mas 5 ± 1 ◦ respec- , ± b) b) AU 1 © Copyright 2017: Instituto de Astronomía, Universidad Nacional Autónoma de México n ftems icl rbesi srnm.In astronomy. in problems difficult is most mass the of of determination one the evolution However, its lifetime. determines and it since property, damental only it fit; change. the minimal of very a result produces the does point substantially for single affect this appropriate However, not most analysis. the of type be this could the configuration with observations disks. A that circumstellar indicate the could facts of These deter- centroids the the affect of also mination in could lower; which ex- structures, be more to tended will sensitive are positions observations the resolu- these addition, of angular accuracy lower the have in tion, observations configuration B the VLA the Since this with VLA. out the of carried cor- observation point configuration This the 7. to Figure in responds fit the from deviates that that than observations. accurate centimeter using more using calculated is calculated observations, as mm system, 7 binary only of 5 disks IRS circumstellar L1551 relative compact the the the that of think motion trace we proper better Therefore, observations by mm emission. 7 produced this the mainly hence and is the dust, known, emission is disk it as circumstellar However, observations. who cm (2003), 2 al. used Rodr´ıguez et by estimated that than h opnnso h iaysse 15 R 5 yr IRS mas L1551 4.2 of system order binary the the of of components the the for years 15 of system. span binary time 5 a IRS component, over L1551 north of angle the time) position to and and the respect of with angle separation component projected position south the of (separation, evolution temporal Plot the 6. Fig. PA (degrees) 530 170 175 180 185 190 1 2 3 4 5 360 350 340 330 320 310 si skon h aso tri h otfun- most the is star a of mass the known, is it As plot separation versus time the in point a is There eaain(mas) Separation − 1 hc ssihl larger slightly is which , IL TAL. ET VILLA 1998 2000 2002 2004 2006 2008 2010 2012

Time (years) siae asso bu . n 2.0 who and (2001), 1.7 al. about et Woitas of and masses (1995) estimated systems al. binary et Tauri Ghez T for by results with consistent is e scrua n h bevdvlct sapprox- sys- is the velocity of observed the imately the and circular 2000), almost is al. are tem et disks the the Bate of of (see plane parallel plane the some orbital and make system the to binary that necessary namely is of it assumptions, mass However, total the a system. estimate bi- follows the can 5 and we IRS bound of motion gravitationally L1551 Keplerian mass is the total system that the nary Considering determine cases to few system. feasible the the is of one it are where systems binary particular, opnnso h ytmuigKpe’ hr law, third 246 the Kepler’s about of is using which period system orbital the the of estimate components also can we mass, aeetmtda nlnto nl faot60 5 about IRS of angle L1551 inclination toward an performed estimated have Studies disks. the of supin,w siaeattlms ftebinary the 1 of about mass of total system a estimate these Under we assumptions, 2014). al. et Chou 1998; Rodr´ıguez al. et tively. h 15 R iaysse fteodrof order the of system binary yr 5 mas IRS 25.1 L1551 the system. the of motions of calculation circumstellar proper reliable the compact a 5 allows two wavelength IRS this the years. disks, L1551 from 15 of mainly about emission of comes millimeter span the config- time that B and Given a sets) cover Observations (five and A archive. the urations, VLA with us- the out system of carried binary were sets 5 data IRS six ing L1551 the of observations omdwt h aepaeclbao.However, calibrator. phase same per- the not with were observations formed the since care, with taken EAIEPOE OIN FL51IS5 IRS L1551 OF MOTIONS PROPER RELATIVE 020 5 2002.09 037 10 2003.76 048 16 2004.89 029 37 2012.90 999 -5 1999.99 970 -23 1997.03 pc ∆ Epoch eetmtda bouepoe oinof motion proper absolute an estimated We multi-epoch mm 7 analyzed have we paper this In v real − ms ms ms (deg) (mas) (mas) (mas) / 1 ± ± cos ± ± ± ± α sn l aa hsvlesol be should value This data. all using -335 4 -316 8 -338 3 -336 4 -355 3 -327 6 . 7 i .SUMMARY 4. where , ± ± AL 4 TABLE 0 7yas hsetmtdmass estimated This years. 27 . 1 ∆ M δ ± ± ± ± ± ± ⊙ 316 5 335 5 338 4 336 4 357 3 328 9 i nadto otetotal the to addition In . steiciainangle inclination the is eaainP.A. Separation ± ± ± ± ± ± 181 5 179 5 178 4 177 4 174 3 184 9 M ⊙ respec- , ◦ ± ± ± ± ± ± (e.g. 2 1 1 1 1 1 © Copyright 2017: Instituto de Astronomía, Universidad Nacional Autónoma de México i.7 eprleouino h rjce eaaino th of separation projected the of evolution Temporal 7. Fig. n oiinage(panel angle position and h oa asadobtlpro ftebnr sys- 1.7 binary of the values of obtained period We orbital tem. and mass total the eraig ecluae eaiepoe motion yr proper mas relative 4.2 is a of angle calculated position We its and decreasing. circumstellar time projected with compact increasing the is two that disks the found between we other separation addition, by In reported those with authors. consistent is value this .d aFet:Gaaaaa aic,M´exico. Jalisco, Guadalajara, Fuente: la de E. .M il,M .Tiia n .Rd´ge:Dpraet d Rodr´ıguez: Departamento T. and Trinidad A. M. Villa, M. A. L5 289, 2000, ApJ, 1985, al. M. et Cohen, J., & C. H. J. Clarke, Bieging, A., I. Bonnell, R., M. Bate, de (Universidad ac- DAIP M.A.T. from Guanajuato). manuscript. support our on knowledges report useful very respectively. Separation (mas) NA,37 773 317, MNRAS, po otl14 unjao t.320 M´exico. 36240, Gto. Guanajuato, 144, Postal Apdo. ewudlk otakorrfrefrthe for referee our thank to like would We

300 320 340 360 380 9520 0521 2015 2010 2005 2000 1995 − 1 hc ae tpsil oestimate to possible it makes which , REFERENCES b) .Sldlnsrpeettelatsursfits. least-squares the represent lines Solid ). Time (years) M ⊙ RPRMTOSI 15 R 531 5 IRS L1551 IN MOTIONS PROPER n 4 years, 246 and a) opc icmtla ik fL51IS5(panel 5 IRS L1551 of disks circumstellar compact e

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