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MICROCOPY RESOIUTION TEST CHART ANSI u-d ISO US' l_MAB' No ; 1.0 I.I I- lAJ 1 2.2 '■ '- 111= 1.8 1-25 IIIIII.4 IIIIII.6 ^ APPLIED ir^yMGE Inc ■:/ / ' ^ . »'4* • 1 'y-i\ PUBLICATIONS 111' llIK dominion I^stropfjpsital Obitv\)atox^ \ icroRiA Vol. I, N... -'I uNivtRSii({i».'-.*nt.\! Q'B THi; Sl'llCTHr.M OF N()\A CVCNl I'fJO WIIH A NOTi: ON Tin; SI'KCTIUM of .\0\A AQLILAK No. :5 ItY \V. K. H AKI'KK Oil Annual 2(lth, r,»_'(l. a ii.'W star was (liscovcrcd in tlic coiistcUatioii ("ycmis hy Dciiiiiiij!;, (if Hristol, Knulaiid, wliilc he was onuaKod in ohsorvinn and plotting iiiotcor trails. The aniKiuiK'cmcnt was caljlcd to Harvard the following day, l)ut did not roacli licro until the 2:ir(l. For tlic si.x wwks or so previous practically every ninlit liad been dear, but a spell of cloudy weather set in about that time which greatly interfered with the observation of the star. Then, too, the cloudy si)eU interfered with our regular obscr- \\u^ prograni of I^oss stars, which became 'Towded in the early evening hours, and as a (•onse.M1N1..N AMIIOI'HYSKAL OUSEUVATOUY ov.T 1.-. ,.uw,itu,lrs un.l tluTrfur.., wl.il.. less t-rilliant at maxinmm than Novu A<,u.h.-, .t outrivall..! it in th.- ..xt.nt uf its varia.i..n. K>tin.at..s of its ma,n.t,ul.- won- mad- ,„,,. i,v „„. .vrit.T wlM.n ..l..ar n.-athor p..rn,itt...l. .ill-.r w.th tl.o nak.-. .->.• or w. h ,.i„„..„l.r., or son>..tiM..> w.th llu. l-in,h lin.l-r of tl.. tH.'scop... Dr. H. K. \ ou.-K also k,,,t a n.onl ..f it^ n,a«nitu.l.. fron> ni^l.t to ni^lit an.), though nuid- <,u.t,. nui,.,H.n.\.-nily „f .„,. unotlMT, tlu- nak...l-.-.v.. ..Mnnat..> ^i-ruTally ann.-.l to 0. 1 n.apntu.l... Ihv nova w... nMnpan-l witl, tt... M.rronn.linp stars, tl.r map>itu.l..< of tlu-s.- Ikmhk tak.-n frou. Ilaivanl .\nnal>, \ ..hnn,. :.(». My osvn ohMTvations, limif.l in nun.l.cT as t.i.-y are, are Hiven hclow. Ma(;mtv OK OK Nova ("Y(iM l'»2(), AiiK Spl. 24 7 2". -7 27 • 7 2'.l-7 ;iO-7 :ii-7 1-7 :i-7 entirely too few to decide the matter, vet, so far as they fro, tiuT do noin'veai iun- ^'.scillations in l.ri,;htness so marked in Nova Persei and in Nova Acjuilae. The decline was very rapid but continuous. General Description of the Ppectuum The plates of .\u«ust 24 showed a strong continuous spectmm with broad absonition iin.-s of hvdronen displaced toward the violet corresponding to a velocity of t)5() km. per soc approach the e.iuivalent of •) angstroms at the H7 region. Broad but famt and more elusive absorpti..n lines which could be identified with enhanced hues of iron and other ..lenu-nts, w.-re also present with .lisplacemonts similar to the hydrogen lines. The H and K lines of cal.'ium were esp..cially strong and similarly shifted. As there seems t„ be some ditTerenc of opinion as to wlien emission first made its ai)pearance, it may not be amiss to record that there seems no reji-sonabh- doubt of its presence on our plates of this night at C.M.T. Iti.^ hours. Its presence at Uy an.i farther to the violet is open ,0 .piestion, but at Htf and at the enhanced lines at X4924. X5018 and Xoim there is a decided strengthening of th.- continuous spectmm which is unmistakable. Fine sharp H and K lines of calcium undisplaced were also a feature of the spectra as in other recent nova>. The deveh.pment of the spectrum during tlie remaining day> of August and the first few days of September was marked by the formation of the usual nova emission bands, ^^ THE SPECTRUM OF NOVA C-kGNI llt20 2()» tlH-ir inrn'use in int.nsitv n-lutiv. to the c-.,.,tinuo«s s,>.vtr«.n, .uul hy tlu- ..,.Toa.nt h.M..« as is always tho .-as., to tho viol.t of tlu- ..orn.al p..^ition of the l....>s. 1 ho ...u.va lo.. velocities of these .lisplaeen.ents a.e ..uoted i.. the .<"i w ..H. i, is i,uTea.sed \n the interval n.enMone.l fn.n, f..^) km. to nearly 12tM; k.n. ,M^r see. .\s a ready stated there is some doubt as t,. the presence of emission ban.ls to the v.ol.-_t of \\y .... \uKUs't 24, but thev are <„.ite pronou.,ee.l .... plates of the 2.-ith a...l by the 2,th there .s '., marke.! dilTerenee betwee.. the emissio,. a.nl .•o..ti...io..s s,>eetrum. ().. philes of this iatt,^r date, while all the emissi.... bands show eviden.-es of stru.ture, yet it^.s most pr<>- „ounceaxin,a at the suh-s w.th fai..t absonition between. .V peculiarity ..f this stru.ture is thai in the case of hydrogen the absorption divi.les the emission ban.l u,.synunetrieally, there be.ng m..re o a to the violet tha.. to the red. The plate take., the last we<.k of Sept.-mber showed that the .Rht from the star wa-s mostly concentrated in the emission ban.ls, X4(>4() being pn.mment. The emission lines we.e strongest at the red end ai.d rapidly becatne fainter a.s the violet was approached. On « panch. matie plate taken on Sept. 2 wUh a d.spers.on such that from Ha to K was 32 mm, the red Ha line is a very outstandmg feature of the sneelrum This band is the probable cause of the strong orange colour to the teleseop.. image darh.g the latter part of September. The widths of ihe emis,sion ba-uls are much ,"" tha.. wi the case in Nova Aquila.. The thn>e bands to the red of H^ namdy he enhanced lines of iron at XX5169, 5018 and 4924, ami H3 itself are each ^bout 28 ajK" stroms in width. H7 23, Hi 19 and K 18 angstroms in width. In the ease of Ha there is no doubt of a decided increa.se in its width between Aug. 25 and Sept. 2, it bemg very noticeable from even a casual inspection of the plates. If anything its centre is more to the red on the latter date than on the farmer, but no great weight is attached to tins owing to the low dispersion used aiid the band may be considered as occupying its normal position. In one particular at least the spectrum differs from the general trend in Nova Aquila- i„ that the main nebular bands N, (X5007) and N, (X4059) ar. not present on any of our plates, although a month had elapsed fiom the star's ma..imum brightness. I., the ca.se of Nova Aquilae No. 3, whose decline in brightness was much less rapid, only about . o, 10 days elapsed after the star started to wane before the N. band appeared and it was followed within the months time by the other nebular bands at X43t^3 and at X49o9. Widths and Positions of the Main Emission Bands \n attempt has been made to detemine if the main emission bands o<-cupy their normal positions or if they have suffered any displacement, but ow^ng to the ack of definition of their edges, the det^m.inations are not very trustworthy. The fo lowing tables, however, give the results, which may be considered as approxmiate values at 18908-1 i 009.i^5710 •^?:lrf' in iii.K vnoNs OK mr, d" M,M.,N ASIKOI'HYSICAI, OH.KKVATUUY ■:::i:x:r:r::X :f;-;^:';tt,:!;:::::;::tl:;;.Tr::; ;:::,,,:r:\;::,:;"::-,':x::::.::^;:"- - ■ -- \\ 11)111 oi- I;mi>sion IVsm. (In Aini^iniiiiHi I'lat.' ni,Sl.I,A< KMKMS OF 1:M1SSI0N UaMJS (km. i«i w') ■itOO m\H wn nd 117 Hi 4".i:i'J . 4i»:!:v 4'.>;i I 4<.«s. 4'.>;!'.>.. 4".UJ.. r.01 1 . . WW.'. COM Miuii> + l — ss - 1(1 - N'.t - ;i(i i ! -18 1 - 33 - 71 + 1'.K) + 174 + is^. + 27 + 2;t + -M -r 11 + .-,1 + 21 + - :!l + 10."> + ;i5 + 170 + 32 + 77 + s:{ + 20 + 131 M,..,„ uf IJ .,.as„r,s on 1<> pint, s = + -^ l^"' l"'"- '^^'^ x= + •") aiigHtnmiB ut Mp + 2'.> + SO + 124 + 85 +57 35 M.^. ^i*--Ii: ^)-m^5^-:s5;jj^>4ir;^.^j^^ B«i*l!-lif ::^;^^- ^-;^ Jk>- :t>!^[^^ ^i^ THK &l'K(-lltrM OK NOVA < YtiNl \'.>20 Mkasi uKrt OK Ahhoiiition Hanu.h 4W.S III. 41>-.x.t 4U32 " 4933 4034 '» 4'J3« '"' 41I3U 41W2 " 4i)4:i 4U(j(; " 49A1 •' 4977 4 "Iti ■J.'. 711 i'. 7«) '.'7 7tM •J7 7H') ■».l tW ;u) 710 :m) 7lti .il 714 1-715 2 7511 2-77h •'.•777 24 •7f..'. 27-753 25 727 >li:ir|. \. lix-.iy \t....l|.lll>M 1,111. » Wi II :.li.| K M ♦H5 i H 1 i 21 -15 2 1 A IMVI 11 2! -17 4 ti - 71I7 H U -lU tl 5 s7n h 2 1 Itl ft •i - »47 '-• !j -10 3 - 1 \m 7 IJ -15 5 um< ** i ", 1. 1 - 1077 8 i 1! 11X5 '> 1 in 4 U nil i o ) 10 1 5 - 1 UK) -1110 '1 i 2 i l.H -17 2 -121H -lUHl 1 2 i 1 ^ 1 » 15 4 14 7 5 6 -1164 3 i I 1(1 1 -IIS.'J 3 1 I i IH 1 ,„, , „ ,„ „, „r ,1,. W„ ot .he broad ban* .cro u^.l u 1, 1 A« _ 4623 4586 44U7 447C» 4472 4l.')() 44'.'4 fiHAKP H AM) K (AI-dtM AWSOUPTIUN Vttentiou ha. been called to the fine, nn.hsphued cahiu.n lines, an.l ^]^'J;^;^^^ .a,ler Lntains the measures ofthe 16 plates.. .l..h tl.e ----,. ;;;;;- ".iLfi^ ii!^^ 272 jTHi.n AiniNs ui nil; i H.MIVIiiV AVIUnl'IIVSK Al. . .H>K.UV AH t»Y :;;:::;:;::::::''-;:: :i:;;r:r;::::i-'::r^^^^ N„vM(irn.inHn.Mi I'.M'.', uimI Num. \.ill|t I Mll--H'll ll<« ;il,~iiri>liiMi Imiiil Ha ii;,rrinv iit).-'ii|i'ii"i ..ili.c.rpliiiii iri.li (iiuii :ili-<>il'""" Willi iiti«ii|iUi>ii lialliiW ;it>"i'lp'l"ll ;,|,-|llIllUMl ' .' Iinm.l ;iliMiriiliiin liriiMil :ili.--l.«iipii<'>> 'M I.IIMIl.U Sl'lX TIU M I'L.ii' I'.'.tl l''-"". AiiK- -•'> (1H71 :il,>..rpiiipii fi.V.7 :it.-.prpiioii (■^■,4-j lir.iuil iiliMitpii"" tkWJ al.xirplii'ii lipi:, i,li-i.rpiii.ii ,iH_. Mr\ lilna.l :,l.-lliill ;,<,4i| vil\ liIiMiil :ili.-« liriiiiil uli«iiliii(■,! ll-» ftliHirpliiiii -jiii vriy liriiuil ;ili-iirpliiiii ,-,loti aliMirplinii .-,01(i 116 lllllSMiill .-,001 Hi iilwiirptiiiii Hjoy sharp .•iiliiiim H n'l" nil I liiuail iili^ II :""' ll« IStll sharp 1 ill' iulii K ill'' 4S4ti liriiud K iili^orpliiiii. 4HI7 47:i4> 4*'i)Ni 4.40 44',t.'i 447J 44:* 44:<4 44.IH 4;i.s« 4;ii:i 4;i'js 42S4 j.'i'.i 41(H. 4tK i '■ uliH4)r|it mil riiiii^Kiiin faint ul)!^>r|)lii>n liaitil rriii?»^iini iibdiiriilHiii 21 A » hi'' irMih?i<>n irriK 22 A wlili' 1'i.VH .il.«irpl 11.11 liarmw l.l.■.^ 1 .< -loll .U't \ Ml'!' ituio . iin^..i"n '-.'. \ wi'l'' : ttls t . II 11 jr. \ »i'l' tkU'iT .1111,-1.111 llff 24 .' >iili-. ri.i.'iH7 nliMirpliiin . .VS7H CIlllKKIUll rAi:>-2 al.wirpliiiii »> ak ,.'«40 ttl.w.rptinn tji (iiiili' 5.'*2 ftlisiirptuiii 12 A Willi' .V.7H iiiii.<«inn II7 24 V mill S.V.ti ahMirptii.ii 1' iiirfti .•..'>;t2 I'lni^sinn faint IH A wi.li r,422 al'i fain' 20 A wiili' .'■>;io."i ''iiiiMsion 14 .\ will'' .\-n« i'iiiiK..4 4M0 It'i'll < 4 tlVJO 4li<».'> 4.-.HI 4.VK) ».-.»'• 4.'i;J7 4Al<.l 44M 447« 444>l 44.'i« 44:tl 4:t7.-. 4.^42 41(44 4:mm) 42«2 4234 4I7« 4102 :!li7l 3fMH 3t»3;i 3'»:« The illustrations uso.l aro direct ..Mlart?.-infnts .,{ the spi'drum platos, th.- inaKi.ifi- cation being .>4 diameters. Being prints of ..nlargements of tlie original negutiv-s. they are, of necessity, negatives tln'inselves. While the writer is i-esponsihle for the measurement and discussion of the plates, all of the observers shared in the work of securing them. Dominion Astrophysical Observatory, Victoria, B.C., .Ian. 14, l'.t21. .m^m. ',-^1 ^m^^:,7ii^^ •_>7J I'rm.irATioNs of the I)omini(»n asth. .physical ouservatohy NOTI. ON TIIK SPKCTKIM OK NOVA AlilH.-K No. 3 The toll.minn t.nf .•uMluii.s a Uvwi iU-M-vipUnn ..f thr rluinu'tcr of the sp.-ctrum on four (lat<- in I'.HIt and ..no in I'.t'.'d, and ii.chid.- al>o a more d.^finite dclcrMunatiun of tlic i)nvitinn of the llrf •■mi— ioii hand in l«.>!S. T\u' n.'W plato were taken at this oI.mtn atoiy with th.> -innlc prism caiuera in jr.MKTal us.', usinn S.r.l M) plat.'s. They ar.' as follows: I'l.-llr Nil 2087 •2155 2iT.i 4141) Ual>' M T j Kx|>iisiiif I Miiti. licnmrks I'll'i. .lunr :i!n27. .lutir INSTS . . .Illl> JISLS Si;it IJ-.jiH> lll-.'O, Apiil ■.'i'.isCi 1 J()ni " i i i'"»P' ^■'■'■y ''1'"' 10'" 7 I C^p 7-.") ; iiiiiijic •■ clc. irir " l)liii' ^incc the autiiiun ..f lOlS the spectrum ..f the n..va has undor|i..m' slight modiHea- , ions' in -he r.-^ion n.v.-re.l l.v our plates. nan>ely fn.n. XMm t.. \51ll(l. Those ehai.fjes :nay he sumn.e.l ui. hv stating that the hy.lr..)jen en.issi..ns hav." vanished disapiiearmn Ui-sl fr..ni the vi..l.'t en.l ..f tli." speetruiu and the ii.'l.ular emissions are m.ire c.nj.li .•ate.l h" reason of numerous al.s..iptioii lin.>s erossiiif; the hands. The emission hand, which eMende.1 rounhlv fn.m X4(i(M) t.. X470(t. was v.'iy faint in HH!. relative to the other ..mission han.ls, and harelv a tra.-.- of it is se.-n on the i-fJO i.late. althoujih all plates could with profit, stan.l nmr.^ .■xp..suiv. The .■ontinu..us s|.e..trum. which at the .'lose of lt of abs<.rpti.m lines when they reached their iiiaxi- n,un, di.pla.-ement ab..iit th.' end of June, 1018. The impression one gets fn.m a casual inspction of thes.. han.ls is that these isolated strips are really the violet .-dges ..f baiui.- ai.proximately 55 angstn.ms in width, which have been " eaten out " by absolution, leaving only those strips and the central secti.wi of 12 angstroms width. r-ISf'j-V : -: 'i C:^ , '-r.'-V ; ,i*IKi.^^- THE SPECTRUM OF NOVA AQril-.E NO. :<.) The measures <.f these is..hi1e»l strii)s on the iiHsun.pti.m that they are veloe.ty (hs- plaeenients are j^iven in th.- f„ll.miMK tal.le, plate N... 1041. taken I'.MS. Dee. 15, Innnn added for reference. The veh.eities are redueed to the sun oidy and m e..n.putinK them 1 have used the wave-lengths for the nebular i.an.ls as Kiven l>y Wright m \ oh.ine i:{ of tlie I. id. OhMiriiliir!/ HiiUdin. Nakrow Emission Strips j 1 1041 1 2087 1 ' 2155 1 ! 2473 2tt25 4141) 5007 02 4fl.W09 48t)l •.".;! 435:1-37 -IfwDO - lfi;')S-5 -I7.-.5 -17t>l -173'.)- -1772 2 -1763 4 -1744 n -174S-2 -17«Wj 3 ' -1751 4 -1733S -1737-i» -1727-0 1 i -1740 5 -1739-1 1 -174>t J -17.^.!t-2 -Mt-an RtHliiclioii losun Vi'lo<-ily. . . -ltV.5S-H - 10 (> -Ifiti'.t -17.Ml-."> + 12 -(i -1744 i -1755-2 + 6-3 - 174() 1 -1743-3 -1733-5 j 1 - S-5 - 26-2 ; ' -17,52 1 -1760 ' -1754 2 + 24 -1 -l7:io Main E .MISSION Bands Itiiiid 1041 2087 1 2155 2473 N. X-. Ilz-i 5007 2 4!t5H-2 4S6O0 43(12 S 1 1 , .-,<107-fl 5006 8 4r> angstroms wide and its determin- ation is subject to considerable error. The emission bands become complicated by reason of being crossed by numerous' lines, apparentlv due to some absorbing matter between us and the emission producing substance. One of these absorption lines has be<>n singled out, not only because it is one of the most i)rominent, but also because of its presence in the hydrogen emission ban.is all through the latter part of 1018. Fnmi the Ottawa spectrograms the writer found the corresponding velocity to be -440 km. per sec, referred to the sun. l.unt and oth.^i- have since got almost identical results. While the line is not (|uite so well measurable in these as in the 191S plates, due mostly to the less dense spectra obtained when the star was faint, yet there is no doubt that it is similar absorption which has made its appearance in the nebular bands. r-T*-f*Vr L""vi-,ft' ^*zSM^^^^^^^^m^^^m^^^^ •27t; ITUI.ICMKINS (IF THK DOMINION ASTi:oPlIY>I(AI. OHSKKVAVOKY (HAIiVI TKUISTIC AbSUUI'TION I-INK IN F.MIS.SION UaNDS -^-^ mil •J087 •Jl.V. - in:! N ■ S - lid 17 -4f)l + r..:i -- \:m •J47:i 1 -»7!l 1 -4.-.1 .-. -|:i7ii j -45«)-2 1 - S ■ ."i - |i'.:i 2^i'J5 .■, - 47t) 7 - Mil II -47'.> 8 f r.' 1! -4tiO 1 -44-. •-' -410 .p 4Mil ■:.:■. i:iiNt:i7 -4.-i(»S -4;ii-4 .:.::;:.:,:. lilllllllilill In - VrliMilio nil -44M ^ 111 r. - I.VJ -II2S - 'Jli'.' - lO'.l MlSCKI.I.ANKOIS AllSOlil'TION I. INKS lllil 4:iNJN 4:;7r.'i i:',7l II 4r)ri'.i() 4(i:i.vJ i:.4'.i 7 i;iss-r) 4:iN.');t 4:ivJ i:i77 :i i:i7l '.I i:it'.!i ■ ."> i;i47 :i i:! i:i .' y.vM 1 ■Ji: ■Ji7;i 414>.t M.an 4:ill 1 - - - - - ! :M.',i'>'i .•.(KSti'.l .'iO:iti 7 :,(vjs li .'.IVJSN i rM-22 ■ .-) .'idlli .") 4'.i>.):!-.'> ."il)'2S-7 41INN;! 4'.is:ii) 4'.'NS'.' IIINI! J 4'.•^7■4 , 4'.INS0 I'.in:!! 1 4:isH-.-) 4:!H<1 ■ 1 1 . ... 4;iSN-7 4:iN2S 4:iNi • 1 4:is2 4 4382 4877 'J i:i, . 4 4:f7:.'.' i:i7-' J i:ir>!i 2 l:irj il 4:174 1 4:!7I -7 4;it)',t4 1 4H4J0 Thk Kmission Hand at IU 1. \iilu.HC 1\- pane 27:5. of tho Publications of tlii" Dominion Ohsorvatory, tlio wnli.r'^aM- a -unuua.v of tho oMiission sp.-Hn.n. of Nova .\.,uila.. No. :?, wherein he fou.ul the en.i^-ion band at H,^ to he about 54 angstroms in vvi.ith with its eentre displaced •U.nut I a.ifistron, to the violet of its normal position. This wa> based on 28 plates taken WM^^^^'" ®r-S^ THE SPECTHl'M OF NOVA AQt'IL.K NO. :{ 277 at Ottav^a between July 19 ai.d Noven,ber 10. 1918, the plates earher than t^jose nd,- c-atinK a displa<-e«,ent of 04 angstn.ni. hut with limits p.K.rly deter,nmect m..re accurate deternnnations, "the emission ban.ls were about 1 angstrom to the red m each ease. This^cin-un.stance of a negative displacement in Nova Aquilae seemed to impress itself on the writer, and on coming t<. \ictoria a few preliminary measures weiv made on the plates here with somewhat similar results. \danis tinds ..orroboration of this violet displacement ..n the Mount Wilson plates. as recorded in .Utrophy.iral Journal for March, 1920, page 120. Lunt discu.s.ses the emission spectrum at some length in Munthly Notices for March, 19'2(), and gnH>s results for the 3 hvdrogen bands 0, y and 8, as well as for the nebular bands N, aiul N,. He finds an average displacement represented by -51 km. i)er sec, the e<,uivalent at W of 84 angstroms to the violet. His displacement at H/3 alone is 94 angstroms but this is not comparable to my result because of a correction which 1 made an.l which I)r 1 unt preferred not to make- namely, that re- fine, sharp calcium lines as reversals indicating the true 'velocitv ..f the star. On such an a.ssumption a correction of +0 31 angstroms would be required to Lunfs displacement, making it 0.G3 angstroms. I.unt considers this view erroneous and looks upon the broad emission bands as giving the true velocity of the nova, namely, -51 ti km. per sec. The purpose of this note is, however, not to discuss this pha.se of tlu- <,uestion, but to give the results of additional measures. Looking over hunt's results, I l>egan to wonder if I had been too hastv in considering that no reliance could l)e placed on measures of the other bands. To that end I have examined many of the Victoria plates and 41 plates taken at Ottawa between July 1 and November 30, which the Director, Dr. Klotz. was kind enough to send me, ami have not felt like changing my fonner opinion that measures made upon the other bands are only rough approximations at best. True, the nebular lines are occasionally definite, but the comparison lines are not always of the best In the early stages Hy is sharply defined by the absorption line at its violet edge and fades oiT very gradually into the continuous spectrum at its red edge and later it becomes blended with the nebular band X43t)3, so that uncertaijity prevails in either ca.se. However occasion ha-s been taken to measure H3 again on the 41 Ottawa plates 278 ......... Ar...NS OK THK ..OM.N.ON ASTHOPHVS..A,, OBSK.nATCHV licallv I lie same interval, with the .,,,1 „„ •_.(, ViH<.ria l>lates a^ well eovering pradi followiiin rc-ult : 20 Nictoria i)late: n Ottawa plater 48fi0.420 4St)0.4t)<) 1 c... tlw. •'(> kill aDDHKieli, is 48t)()./l> same as th.- fnrmer hut less extensive measures. Dominion Astroi)liysieal Observatory, Victoria, B.C., December :<(», I'.fiO. ..i^.^:i ij^trfj-;-^ .-^/ff. 3- O S IJCKPU &411O 66111) fi I «iis^:^^^^?sa^ ^.i^S^i^Jf' %?^ >;?^i ■ fe? i^44£m^iL^'iyM \