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1995 Ultraviolet Temporal Variability of the Peculiar Star R Aquarii S. R. Meier USN, Research Laboratory

Menas Kafatos Chapman University, [email protected]

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Recommended Citation Meier, S.R., Kafatos, M. (1995) Ultraviolet Temporal Variability of the Peculiar Star R Aquarii, Astrophysical Journal, 451: 359-371. doi: 10.1086/176225

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Comments This article was originally published in Astrophysical Journal, volume 451, in 1995. DOI: 10.1086/176225

Copyright IOP Publishing

This article is available at Chapman University Digital Commons: http://digitalcommons.chapman.edu/scs_articles/139 1995ApJ...451..359M THE © star a & clues Electrical temporal nebular period IUE order an general. the 1995. much 2 This 1 Hollis AsTROPHYSICAL analysis nearest Present IUE R The satellite to to from Aquarii. American Guest Engineering, work parameters emission the "jetlike" smaller in This in total which far-UV ionization He variability yr the tures tions Explorer 1992. Subject blackbody em- and and of between T* add variations (1986) address: This High- star ©American intensity. a timescale 1986 = emission II of nature 1982 Observer. L 3 more may hot result Astronomical post-shocked ultraviolet 61,000 A, of is A.1640 We suggest all (NE = which A JOURNAL, data headings: paper emission ULTRAVIOLET concerned December the studied B, 1982 and component. May lines University 1.5 (IUE) filamentary help Mail previous existing have insight levels of of vary parameters, could and and jet), in NE mechanisms K We x as set, 1. shows Society. the R Code low-resolution to May to in that is 10 the Space for 451:359-371, INTRODUCTION analyzed suggested with Aqr. satellite physical D flux jet of electron the have the 1985 determine the ionization in 15 a to indicate stars: binaries: of 0407, All ultraviolet Astronomical paper H the of region. and carbon, the jet with and comprehensive are em and California this rights R Center time. results (A.A-1200-3200) far-UV These A.A-1200-3200 structures. II We the August. found activity, La hot Aqr and strengthening Environment (NE individual region consistent reserved. 1989 1983 intriguing of in parameters studying Jolla, the by NE temperatures This determined for by that TEMPORAL 1995 symbiotic Low-resolution component. how the R nitrogen, plots possible are were source jet). Kafatos, Earth at ultraviolet much variability data ultraviolet June Printed Kafatos, Aqr, December, CA jet However, September analysis and to the San symbiotic not far-UV The 92093-0407. The limited indicate astrophysical are Observing in Technology (R and obtained with the wavelength Received system, Diego, (NE in ionized NE George stronger U.S.A. study and coupled accretion of Society oxygen, H - increasing of Aquarii)- He results Michalitsianos, the electron since Michalitsianos, far-ultraviolet could 20 the jet Estimates emission jet), a of spectra as emission-line emission absolute over Department in to II VARIABILITY NE Mason that decreasing star 1994 and of we a have II region symbiotic absolute T;, A.1640 scope. a Center, with R Aqr and result evidence to of regions provide and jet. Space all "' a low believe disk September STEVEN Los MENAS the jets range R densities University, • our the 4 20,000 in were steadily and ABSTRACT also far-UV stars: Aquarii the line Angeles, for modified silicon of is Remote value In yr far-UV Research/CSI in of Provided parameters of is intensity, 386 ultraviolet increasing line the - have electron AND 359 the fluxes used intensities line-emitting that KAFATOS R. 12; & peculiar- K ISM: of of day Sensing number CA increased Fairfax, of intensities MEIER accepted spectra compact Hollis. jet max system system (R (Whitelock every compact inquiries. wide white Squeren, symbiotic symbiotic. OF & astrophysical accretion emission been (H the 1;,::;; Zanstra ne to 90009 the Since R may Mattei (Wallerstein while pulsation Aqr) Institute jets = temperature Aqr for calculate THE II (V) 2 Department, high by in VA range analysis 1 NE tabulated. wavelength 18,000 x 4 1995 dwarf as has of Moreover, region) be excitation. obtained and the associated the 22030-4444 = (M7e covering over & the the H H ultraviolet: regions disk jet a method from This ionizing star 1981), and ionization March This complex This a and 10 PECULIAR JD been Scalise 1987), of function II II hot discovery outflows result 5 SW are jet, period K and NASA the region. indicate Department region +pee) the excitation, (Kafatos R 2382892 em- binary wavelengths The the and & component known from 30 it Aquarii In compared and and counterjet, of entire R Aqr Greenstein from with yielded a we properties 1978). photons a has Aerospace of We NE 3 addition, with a L 13 is of of stars lines Mira and with (H increasing The - observations an find star of Astrophysics = high believed the that + have jet to radio et the time the yr of period STARR is system (R 6.3 a II 386.3* expanding R an SiO undergo the Physics, al. 386 a the is longest of period system that complex Corporation, region) with beyond variable Aqr) Mira. are Aqr the International for 44 value found x to feature effective not 1980) of 1986). we v N to NE closest day 10 yr maser to E of also discern the H has the the line-emitting is soft each has present variable 14 (Mattei period consist between IUE contains Finally, AQUARII known and erratic II A.A-1238, of the during and Mira and that the At variations jet been em most emitting emission given. A', been X-rays. that region symbiotic temperature other 1;, emission only a SW structure, possibly observations. Lyman Data the (H ne has the observa­ the ~ (Willson, distance has plots of detected outbursts. & the on binary Ultraviolet prominent is the = successive 26,000 1240 1979 a II temporal extended a to known and Allen declined In 6 x 6 an embedded volume a hot recently subject region) region, nebula period in System of probe star limit, "'1.5 addition an ephemeris and and (Lepine, fea­ orbit subdwarf the 10 the the of Garnavich, at 1979). of K associated symbiotic 4 as The "'250 virtually of peculiar formed well of many most in This to any Le pc or as of a a 1995ApJ...451..359M , (Mira and P.A. Relative Hollis (1982) into VLA. optical Hollis, material that recently which er~tein R - Associated 360 FIG. The 8, Aqr 3 A' = The three makes rivaling variable). et 3 of 45°, 1.--(Bottom) the first existence Further to a!. & Herbig R VLA plates & recorded in and Aquarii. Universities feature (1985) discrete ©American Michalitsianos -15 hot R Aqr Greenstein detected the of the feature 33 the 23 companion taken of (1980) VLA Cl, optical visual (Top) of VLA Cl 381-- 361-- 341-- 40 46- 44- 42 41 National outburst a regions B extended Inc., feature unique (H - - is the radio VLA in 6 14.5 confirmed 6':5 light n under em ~ spectral (1980) region), ·#o 1980. NE at Radio 2 C2 (1983) of observations Astronomical 14.4 frequency achieved em occurred astronomical "' 0 00 P.A. I I!) "' of fn 0 ~ II contract emission: jet is jet and 38" 40" 46" 44" 42" the Astronomy C2, 0':5 Observations = detected 43 14.2 14.3 structure 14".6 region in at the 6 29°. Mira A, at em with the 6 a between and P.A. Also existence observations of maps em visual (1) the (Mattei extending configurations radio B Observatory 14".4 = object. 14.1 shown feature a is (NE resolved NSF. of 55°, one "jet" R Society magnitude 1928 by jet), 14.0 g Aquarii region feature is of I- & of In - - - the Bat 14".2 and Sopka Allen the and the by - 1977, A' of is the 386 A, 6cm obtained 6" operated A A' 6':5 with Kafatos, MEIER jet features B, nebular day 1935 is (SW system 1979). NE • mv Wall­ et D, 2':5 from from 14".0 LPV the jet). Provided Cl, al. in by of of by at & KAF 44".0 43".5 jets, found The from and approximately 0 distinct discovered obtained of20o continuum lines marily radio tional A.A-1907, present presence A. A.A-2975, grated in 1). Kafatos Kafatos Hack the tially region, both N v N shorter spectra associated R R Kafatos, 1991 14".32 = The Ultraviolet Aqr Aqr III] the Hollis ATOS aperture by 1230 most compared A.A-1238, C2...... ,--., ofO related features December {I • (Paresec, 1994). at continuum independent ,...) observations A.A.1660, NE from at position ultraviolet radio 14".30 .. wavelengths, gives the of components in 2803. (1988). 1909, Recent -8':4 1986; of et & a A with I recently ' the jet a , nebulosities .... A.A-1302-1306, .. the which position al. two determined From features to ~ Hobbs NASA 1240 counter in A, 14".28 morphology evidence observations These (Michalitsianos (1986), from C H the 1666, with 10" the Burrows, The Kafatos two of B, the reveal distinct Hubble n] and n emission emission gradually discovered near-UV and NE the SW Faint 14".26 .. ,, of at large the NE the region angle 1980; jet · C1, jet A.A-2325, similar N (Burgarella emission ,~ Astrophysics using ····' He jet, ... IU a 6 D. wavelength ..::~ that central (Johnson of . III] (feature weakness jet structures emitting that continuum Space et & C2, em ·-. C size .. E 14".24 II Object and of , R can 2cm Meier Horne al. taken of 2 II A.1640 integrates in observations, A.A-1747-1753, in 10" to rises higher by A, 29°, Aqr feature em A.A.1334, 2326, emission of ,, (3) R the lines & 1986; object the be Telescope the and 14".22 Kafatos A') x the Aqr VLA & regions, the (2) Kafatos Camera at with 1980, et of between emission 1988) 20" found H NE (Michalitsianos, counterjet, in for flux [0 A', IU excitation Paresce are N a feature C1 al. compact II Hollis C1 exhibit 1335, the aperture UV observations, Data position E feature, decreasing v jet. whereas region (see u] the 1982; superposed that itself 1994). et with aperture in and Mauron (HST) SW C1 Si 1982) (FOC) emission The 1986 in al. A.2470, C Fig. Michalitsianos A central et 1992; III] increases several (the System IV He the a direction. consists H (1989) Michalitsianos, at nebulosity conditions which feature However, al. relative position angle appearance the A.A.1548, II 1). and October A.1892, observations II 2':5 NE H centered allows et region wavelength and 1991). Paresce in placing found Hollis, on primarily II al. star emission is detected and and of the extends Vol. toward of D, region) (1985) essen­ to Mg a Addi­ C angle 1550, 231°. (Fig. inte­ four H was and The 45°, and pri­ UV SW UV the are the III] 451 at & of & of & II II 1995ApJ...451..359M (SWP) (LWP/LWR) cessing The dispersion in have resolution, which bration No.1, spectra ensures ately ined obtained lead LWP/LWR Aquarii the tines time-dependent using reprocessed photometric NASA IU archive presence observed the -4%-5% The All R E H detection to Aqr IU exposed developed not ultraviolet IDL IU include II has and absolute 1995 Goddard IU were of errors E that were region, System E of been with by appears the E spectra ultraviolet for a (Interactive long-wavelength ©American spectra and v N the using uncertainties calibration collected limiting all (222000-3200) lines. retrieved IUE of regions 2. the the corrected and 45 (Brugel NE at emission-line EXOSAT UV three emission soft Space spectra ULTRA (IUESIPS) to strongest 10" the and the Regional It of SWP the and be data X-ray spectral should R at (221200-3200) spectra most x RDAF LWP/LWR .12 Flight and Design signal-to-noise eta!. largely and VIOLET Aquarii for 20" different SW in in in have satellite - (221200-2000) Astronomical SWP emission Sequence SWP SWP SWP SWP SWP SWP SWP SWP SWP SWP SWP SWP SWP LWR LWR LWR LWP LWP LWP LWP LWP LWP LWR LWR SWP analyzed. both extinction lines current prime/long-wavelength extraction Data large-aperture the the also 1984). 0.1 low-resolution, jets. Camera/Image Center data intensity resolution at presented Language) circumstellar been OBSERVATIONS 46585 40265 37914 32645 observed 29989 29543 29542 20069 20068 41706 41699 A 36397 31102 10557 10558 NE 9814 9402 21998 20449 4619 12404 NASA/GSFC. 9255 9251 15662 16016 16013 were and be epochs, The the Analysis (Viotti for high-resolution Number reduction noted IUE jet (NASA/GSFC). in ...... analyzed of ...... short-wavelength The -10%-15% high-dispersion ultraviolet obtained because ratio. procedures. is the UV is the of have eta!. Spectral all affected emission also data that IU low-resolution, Facility IU LU 0.25-1 spectra TEMPORAL symbiotic and These five Society E 2,448,983 2,446,729 2,445,480 2,444,553 2,444,552 2,444,552 2,444,552 2,444,022 2,448,604 2,448,404 2,448,403 2,448,403 2,448,229 2,447,889 2,447,683 2,447,683 2,447,161 2,447,161 2,446,794 2,446,731 2,446,729 2,445,481 2,445,480 2,445,480 2,446,951 2,446,794 E 1987). using consistent the - the routines. been Julian reduction Since ae Date Date spectra from spectrometer, may spectra 6 SWP by Image UV for absorption KeV (RDAF) line A errors redundant spectra have the analyzed In LIST the the the for even spectra. moder­ spectra star flux exam­ all, prime range high­ • same OF 1986 1991 1983 1983 1983 were 1983 1980 1980 1980 1980 1979 1990 1989 1989 1989 1987 1987 1986 1986 1986 1992 1987 1986 1991 1991 1991 been data Pro­ IU cali­ low­ This with rou­ can be 29 82 VARIABILITY IUE of at Provided of R TABLE E Jun Oct Oct Oct Jun Jun Dec Dec Dec Dec Dec Dec Dec May May May Nov Nov Nov Nov May May May Dec May May OBSERVATIONS 4 5 5 27 25 25 26 3 31 28 29 29 13 31 9 8 8 8 25 27 26 26 25 25 26 28 images region, partial all LWP/LWR most resolution jet, these neither respectively. SW (IP except November from dynamic [0 Figure Figure tinuum. many Vidicon sible The 221907, this 1 The Low-resolution The As low-resolution II], and = section Dispersion jets ionization accretion by shown N prominent figures. 13.6 resonance, Low Low Low Low Low Low Low Low Low Low Low Low Low Low High High High Low High High High Low Low Low High High first results for and NW list 2b 2c presented underexposed SW detectors. 1909) v The the are OF range C (1983 (1986 absolute shows 221238, of spectrum eV). Mg jets, along with jet Table (2000-3200 III] in presented NASA of UV R the The disk is potentials Figures region II and limitations, UV 3.1. and The May) Exposure (minutes) AQR October), overexposed emission semiforbidden, superposed emission have UV total SWP, continuum 1 240 240 240 395 345 300 770 765 200 240 240 260 parameters. 120 115 100 100 100 IU 1242 45 40 40 90 20 45 50 60 60 SW observations line contains Mg UV (Fig. 3. strongest spectra UV E Astrophysics and the or 2a-2d, good in UV DATA jets, II, Lines intensities A) spectra (IP L found saturated. 2a) associated spectra lines lines WP, Figures the line which Hn Hn Hn Hn Hn NE NE NE NEJet NE NE NE NEJet SW SW Hn Hn Hn Hn Hn Hn Hn Hn Hn Hn NE Region of spectra wavelength respectively. = the in signal-to-noise of in of 3a-3d, ANALYSIS and did Jet absolute Jet Jet Jet Jet Jet Jet Jet Jet 97.9 order intensities a of line in and in and the the observational all and presented flat, increased of C Continuum R not SWP 1a-1h, and H spectra eV) that H forbidden IV, in R nebular, Table L Aqr and analysis moderately -10, WR II II Aqr Data change C both continuum to wavelengths ranges region region, were (1200-2000 4a-4b, span remained III], 2a-2f, by spectra are 0 2 of here as ratios stellar, are regions gives System C I parameters emission analyzed. -1.5 a the a dominated taken noticeably for 221302-1306 NE II] the broad result described represent strong and IU shown and + increased constant, the the times. jets, and H A) in for [0 E (C 3a-3b, II, of range lines. were 1980 low­ H con­ SEC pos­ The al)d and III], NE 361 the for m] the by In in in in II a • · 1995ApJ...451..359M 362 shorter (Fig. changes distribution A.A-2795, with and emission-llne 2c) the wavelengths. 2803, and in levels © the American 1991 substantially 0 C Nv Si Si Cn OI 0 CIV 0 0 0 C N N Nv Si Si Om 0 C He He [0 [0 N N Si Si C Hen Mgn Mgn He [0 [0 which shown • • • • b b II IV III] ultraviolet III] I IV················· IV] IV] IV III] III] III] III] III II m1 IV] IV] III] II II] III] II 11 II] 11 Wavelengths m] Saturated Saturated Flux Flux Wavelengths ...... ·················· ...... May ...... ••••••••••••••••• ...... fluxes ...... + + ION ION Moreover, declined is is C C in in in (Fig. 11] n] units units were emission emission Figure ...... Astronomical ...... took have have increased 2d), · of of · in 1.5-2 10- 10- emission-line been been feature. feature. where intensity. place 2b 2325.4, 2325.4, 2326.9, 2325.4, 2320.9, 1404.8, 1397.2, 1393.8 1334.5, 1301.1, 1660.8, 1640.4 3203.1 3132.9 3203.1 3132.9 2795.5, 2470.3 2795.5, 2470.3 2320.9, 1404.8, 1397.2, 1393.8 1334.5, 1238.8, 1892.0 1640.4 1548.2, 1483.3, 1238.8, 1892.0 1752.1, 1748.6, 1746.8, 1548.2, 1483.3, 1906.7, 1808.0, 1301.1, 1906.7, 1808.8, 1746.8, 1660.8, 1752.1, 13 12 averaged. averaged. ergs ergs (1983 times Low-RESOLUTION the between Low-RESOLUTION ( 2326.9, 1335.7 1304.9, em 2323.5, 2802.7 2802.7 2323.5, 1407.3 1399.8, 1666.1 1407.3 1550.8 1399.8, 1335.7 1486.5 1242.8 1486.5 1304.9, em 1242.8 1550.8 1753.9 1908.7 1816.9, 1816.9, 1748.6, 1666.1 1753.9 1908.7 A.(lab) .\(lab) -1.5 (A) (A) - - May), UV The stronger 2 2 Society s - s- fluxes 1306.0 2328.1 2324.7 2328.1 2324.7 1401.1 1401.1 1817.4 1817.4 1749.6 1306.0 1749.6 1 1 continuum times) . most • 1986 except ofO H compared MEIER dramatic NE October II A.(IUE)• .t(IUE)' toward 2799.2 1335.7 1305.9 3186.0 3126.0 2328.7 2472.4 2472.3 2800.4 2329.4 1403.1 1394.2 1663.0 1638.2 1400.3 1392.2 1334.2 1489.3 1242.7 1547.4 1484.3 1304.9 3190.6 3128.5 1817.4 1239.4 1893.2 1639.7 1549.4 1891.5 1904.8 1815.3 1907.4 1663.7 1749.6 1750.5 • REGION I, (A) Mg (A) JET C flux Provided TABLE TABLE II, ULTRAVIOLET II & ULTRAVIOLET SWP SWP LWR KAF LWR 2A 2B and C greater the both region 11.7 13.2 14.2 14.6 15.7• 0.9 2.1 4.0 2.2 4.8• 4.8• 1.3 2.0 2.8 2.5• 4.7• 1.3 1.3 1.1 4.0 8.6 8.1 5.4 7.2 7.9 8.0 6.2 5.5 20068, 10557, IV, The 16016 A 9251 increased by [0 SPECTRA TOS shorter and 0 SPECTRA declined overall compared III] the III], SWP SWP LWR + LWP OF Si NASA strength OF C 38.4 30.8• 27.5" 11.5 13.2 11.9 13.8 18.5 14.4 12.3 10.6 0.8 0.7 1.1 6.3• 3.0 3.8 4.8 1.2 1.4 6.9 2.8 1.6 1.7 1.0 1.0? R II, 9.6 9.1 9.8 4.4 8.0 2.2 UV 20069, 29989, slightly II] R 16013 AQUARII 9814 C longer AQUARII with A.A-2320-2328 II] continuum Astrophysics ofC + levels from SWP SWP wavelengths [0 LWP LWP IV 51.7 39.6• 30.4• 25.9 20.3 15.2 10.3 14.7 10.0 15.0 15.4 11.7 10.0 10.1 15.5 0.6 1.8 1.3 7.8• 6.6 3.6 0.9 2.6 2.3 2.3 4.4 4.4 1.5 1.9 1.8 2.7 1.3 1.8 III], 8.1 3.1 5.5 1981-1985 A.A-1548, 29542, of 32645, 12404 9402 1986 flux in and Figure [0 distribution October until 1550, SWP SWP LWP LWP Data then II] 40.5" 51.2 33.8. 23.9 20.2 14.9 10.5 16.5 16.6 13.2 15.7 11.7 16.5 2.5 2.6 2.7 2.4 9.2 1.8 2d 3.5 0.8 2.5 2.6 2.9 4.0 8.7• 8.2 5.5 1.3 1.8 1.7 9.5 9.9 6.6 7.2 2.2 1991 41699, 36397, C were 20449 15662 (1991 increased III] System (Fig. May. -1.5-2 A.A-1907, of May). 2c). the Vol. In toward Notice times addi- 1909, H 451 II 1995ApJ...451..359M No. jet. increasing spectra (Kafatos excitation fore, displays line ing. tion, originate flux lines Figures took tunately, region with Figure }.}.2795, wavelength Si seen stronger 1909, 1986 1988), lengths imately 10" December). remained ultraviolet May -2-3 (1982-1989), increased Low-resolution The III], The fluxes x distribution 1, We in are most decreasing (Fig. October, we place [0 and 20" compared 1995 and 3a [0 Figure overall indicate 3a-3d. most 1.5-2 and still 2803 emission believe cannot no et in than III] by have IVE essentially is conditions emission-line in 3a). N v N III] ©American continuum in feature feature The regions al. the present IVE excitation a a and + radical and 1986 3d. times + Figure factor and coupled The the UV steadily large 1986), variety wavelength. C first increased that the UV C comment to spectra the lines II] UV an He A line A IVE II], continuum December in greater and earlier emergence detection aperture of changes continuum in the constant instead (see 3c }.}.2320-2328, emission-line ultraviolet II these the flux increased [0 with or spectra intensities "'2- feature of of intensities were spectrum (1987 emission central exist Fig. UV considerably that C emission u], Astronomical on which values than 3 One the high-excitation of previously IV in over receives spectrum (Fig. of December) beyond 2 through Mg the whether flux A. 01 Nv Si Cn 0 N 0 C Hen N Sin Si C of the of fact the ll1548, of flux H in interesting v N • ' corresponding b IV III] continuum IV] IV] IV III] III] III] taken have The ION rises Wavelengths Saturate emitting Flux lines the v N ...... the ...... found in ...... II, central intensity, Michalitsianos ...... II ...... 3b), distribution intensities UV ...... [0 ...... that lines and region }.}.1238, and 1980 IV flux is reason 1991 Low-RESOLUTION NE in increased UV toward of 1989 where }.}.1238, detected these II] of in in spectra 1550, E both emission the exhibits in emission-line R units 0 which H from 1983 C observation volume }.2470, November. jet 1238.8, 1548.2, 1404.8, 1399.8, 1397.2, 1393.8 1334.5, 1301.1, 1660.8, 1640.4 1483.3, TEMPORAL December; 1808.0, 1752.1, 1746.8, feature 1906.7, 1892.0 Aqr. lines argues or Figure have III Society II flux June, short- II, is 1242 high-ionization of the v N have region. C are shorter feature May that were levels of both of 10- 1240 N in feature. by been III] are 1242.8 1335.7 1304.9, most 1550.8 1407.3 which 1486.5 1666.1 1753.9 1748.6, 1816.9, 1908.7 A.(lab) a continuum & and the the (A) the is in as to IV], 13 for shown and and moderate factors increased 3b since (Fig. SW averaged. approx­ ergs Kafatos increas­ the }.}.1907, the around in slightly note Unfor­ can NE NEjet NE higher period These Mg there­ wave­ A fluxes likely (1987 1401.1 1306.0 1817.4 1749.6 C long­ • He JET rises 1983 cm- H NE are the 3a) jet IV, VARIABILITY be jet in in of TABLE Provided II ULTRAVIOLET II II 2 s- 1 .!c(IUE)' . 1240.7 1305.4 1752.0 1665.4 1394.1 1491.9 1401.4 1335.6 1884.6 1817.1 1640.5 1548.4 1907.0 jet (A) compared compared intensity in increase 2-3 method with weakness }.}.1660, spectrum spaced, sion excitation 0 and and excitation and emission-line discount in l1640 last 2C). increasing 2C Kafatos We UV time. that perhaps 0 intensities R the The Low-resolution Aqr the I emission-line III], are findings times low-resolution cannot }.}.1302-1306, flux Hollis Figure SPECTRA of was several by the The data. over shown temporal are either N this SWP 1666, was et and the this OF the overexposed) between excitation in compared of (Fig. conditions conditions to to line wavelength III], of al. shown et 10.3' the 4b 0.6 3.8 0.8 2.5 2.0 8.0 discern 0.5 2.4 However, 2.7 1.5 2.2 1.3? OF ofKafatos method v N strong implemented 37914 levels the the al. individual v N the intensities value (1986) emitting in NASA N R (1991 R fluxes period and 4a) (1991). III] Figures UV flux AQUARII AQR values H ll1238, UV }.}.1238, in C SWP 1989 IV in II because any }.}.1747-1753, emission are found C to May) of variability proved II Figures indicates in SWP region exist the in since E of and AA1334, levels Astrophysics et continuum III]. Again, makes volume the found the periodic line December provides spectrum (ll1200-2000) approximately 0.3 4a 3.3 0.5 1.1 6.4 9.4' 2.5 2.0 1.9 1.9 3.1 Figures 1.0? IV later al. 41706 1242 both 1242, to an in represent NE the and The E NE the (1986), of fruitless. fluxes in 5a-5h, features ascertain lines observations "'1.5 in the spectrum it that the data jet. 1335, of contain 1983 and 4b. period N is jet line the behavior difficult 5c-5h evidence, the was lack [0 NE of are IV] and expanding. Figure Michalitsianos yr flux the set He where continues NE the May C Using III] C intensities H A period taken jet. }.}.1483, of plotted if was IV SW is IV a are II II, 1991 II and (Fig. temporal Data "'1.2-4 jet and any more + weak small to (Fig. A region }.1640 E AA1548, 4a in Si the as indicates C (see determined jet shown a Fourier in spectra know B, in IV+ the 4b). periodicity (1989 May. indicated II] smaller in as total recent 3a). 1991 to has 1487, UV consistent System and The the Tables in in }.}.2320-2328. times and far-UV The a virtually variations 0 increase, et 1550, The the in function declined NE continuum December) the Notice irregularly the integrated December of transform that increased al. and IV], NE data decrease data order the present 2B jet. greater SW earlier, overall from (1986), earlier 0 exists emis­ high­ jet C He with (the and SW We 363 set, the III] jet IV, all or in of of of of a II 1995ApJ...451..359M ~ , 364 over Notice SWP and flux emission coronalline 4 the regions often obtained. LWP/LWR Mira. yr FIG. The A') this UV J! I N ~ in data !:!:!. u:: . ~ 0 E' :::l X E (A..t1200-2000) saturated. the of 2.-Low-resolution the timespan. temporal are 0.4 0.2 Q.6 flux R 0.2 0.4 0.0 0.6 0.8 0.2 0.4 0.6 0.0 0.2 1.0 0.8 0.4 0.6 1.0 0.8 1.0 ©American does increase set. Aquarii Between SWP increasing NV emission SiiV+OIV] between These (2000-3200 not in wavelength Similarly, obtained variability and vary the plots 1979 and 1225-1900 UV in LWP/LWR IU with ~ intensity. between E also Astronomical January continuum C spectra Clll] I the A) Wavelength the plots region m] provide integrated wavelength 386 1980 A.A.1907, of (A..t2000-3200) A, CII]+[OIII] suggest The the ( was flux day -JD November excluding I (A) H evidence ]011] total and obtained 11 I pulsation 1909 region 2,443,850) the flux emission-line Society integrated SWP range LWP and SWP wavelength SWP LWR because SWP H LWP (features Lya that throughout LWR II 1991 by 20449 41699 29524 period 20069 16013 10557 9402 and 0111 9251 ).1216 the measuring He 2d was 2c ~ "1 and MEIER May 2a II C1, intensities they UV far-UV • NE regions. ~ i ~ ' of C2, in 1985 geo­ also Provided line the are the the jet A, & KAF 2000) R the element (- Si emission confirm January minimum and the since Aquarii FIG. Figures IV) UV ATOS JD by total c\1 I "' ~ have !:!:!. u:: and ~ 0 ~ E' :::l Ul E X the continuum plotted 3.-Low-resolution 2,448,600). the (e.g., LWP/LWR 3.0 2.0 obtained that 3.0 0.0 2.0 3.0 2.0 4.0 2.0 3.0 4.0 first ( line UV continued -JD around 6a-6f NASA 0 the IV intensities Geocoronal versus flux flux Lya I, between 2,446,100) E show NE 0 C (ll2000-3200) and observation In 1985 and I IV III], in Astrophysics time jet emission addition, IU various 1983 an emission-line 0 January in E has spectra for IV], upward the the May Wavelength continually line the wavelength C in H ionization total all and intensities of II, (- 1982 II Cll]+[OIH] H the trend C region temporal JD 1989 I II III], NE UV fluxes (A) Data May. region 2,446,200), range. June jet over increased until C flux declined, stages (features IV, began in this SWP SWP32645 System LWP SWP20068 SWP LWR LWP Note variability LWP and 1991 Si the and 7 II, yr 29988 36397 12404 15662 16016 of SWP A, the 9814 0111~ NE after in to period. Si reaching individual December He 3b B, 3d 3c 3a the increase intensity Vol. II III], increase and (ll1200- 3200 jet. which same plots D) and 451 All in of a - 1995ApJ...451..359M No. emission-line intensities. ionization indicate levels. obtained wavelength NE expanding a observe ions n; the that nitrogen, provide same electron correlation, ionization intensities to ratio for equally of times mate that have both ne 10" constant FIG. The In clear JJ each ~ <'l ~b J! ~ the total . jet. ~ !:!:!. u: 1, Q) E e> X :::l x the are the x 6 at the (Nussbaumer similar for element Figures with 1995 20" 4.-Low-resolution This Si nebulosities The between a other correlations at ions formed 0.8 insights 0.6 0.2 0.4 that 0.0 0.2 0.4 more 0.6 0.8 0.0 1.0 density H luminosity excitation the 10 oxygen, 1200 constant III] region. ©American state emitting a large stages imply each II ionization 4 would line mainly - constant form the minima region H em- J(A.1882.7)/l(A.1892.0) for Geocoronal in o 7 1989 of in II lyo: a-7f, fluxes other ions Notice (ne) IV] into aperture a the a for and region Cll 3 in the the I 3.2. ionization variety favor December volume-averaged in 1986) volume. for surrounding SiiV+OIV] and source in in 1400 at in the each H are and the successive gas same the remarkably ionization silicon IUE in temperature, each the the the Nebular the the II feature same is the being an was later were nature maxima) region N spectra element H of receiving decrease Astronomical nebulosities lower IV] H I expense region, this in emission and Wavelength increase NE II ionization are C temperature. used region. II I IV the region data increasing, excited A. 1991 1600 Parameters region of jet the ionization temperature. of plotted (see than well. the in in to density-sensitive NE at are (2JD 0111] the May perhaps of central combined line I density the SW in Since obtain the may (A) Figs. approximately equally most 0 linear jet and in UV This generally states. ionizing the in jet against UV NE may m], the one 2,447,500). result the 1800 (feature is For this 6d-6f) NE star TEMPORAL emission other provides an levels Society as continuum relationship of jet SWP exciting NE SWP would expect at assuming be Assuming The Gill)- example, emission is estimate a jet. x 4 region from source each correlate all proportional increasing A') jet. not 37914 result estimates (l.U200-2000) show ions of ionization These diagnostic of 10 4a the The The evidence measure the the other 2000 R all carbon, flux 5 and Aquarii in • of again of em- of if some these same from case, IV may lack ions esti­ (i.e., line the the and the the VARIABILITY Provided an an to to at of E 3 density, energy, I:.nz geometry is the written have unity nA Michalitsianos, jet where strength (1991) emitting from carbon, disagreement portional (Nussbaumer (Wallerstein decreasing, electron of ne the volume have nebular were with region perature portional between spectra authors em- l(A.2325)/I(A.1335) and and density-dependent density line Michalitsianos the the values whereas because sianos, 1989 1983 ne 16,000-18,000 ~ The 5 x 5 Electron the and is 2 displayed the rise form electron IUE Hollis by 3 N is the ratio to 10 December obtained increased in a November. Earth electron found 10 ofT.~ A,z absolute d are T. was N in in 6 & taken temperature or be the oxygen, T. for solar listed with the the is emitting density chemical region OF decreased 10 estimates A.z is observations, 1986 of were to cm- of UV = Kafatos to closer electron is proportional higher eta!. taken were spherical while temperatures the calculated line em- the streams, the is by 1 the (Osterbrock the density & NASA n; some R over & line with above. a 26,000 3 K density, (Michalitsianos the using used abundance. et December with intensities and Hollis & LO., cube Greenstein the NE is (1991). ratios Storey and electron AQR distance 3 (Wallerstein region factor range into agreement taken a!. The than region. the abundance intensities. (Hayes elemental the a Feibelman the 1982; line density, to curious using the T. to 0. 4 jet where silicon time. the in range 1988), case, of The K rings, a account. yr UV [0 Astrophysics eta!. is value were this may estimate Te by semiforbidden for other Another 1981). ratio value the the f the to is estimate from relative from time period. the temperature-dependent 9 temperature, Hollis III] from In , ('I;,) ne value all & 1974). the of where line n; higher Since and the 'L or although line-emitting of H (1985), line behavior. obtained H or where 1980; solid ionic estimates We was with the forbidden L of this authors. Nussbaumer estimates ofT. with optical This perhaps for 3 is & 1982). II II Si one 16,000 et intensities I In a H indicate J(A.2321.0)/I(A.1660.8 the the d eta!. 1989 intensities. diagnostic in to UV region the region the found L 2 The disk, determined a!. Greenstein III] paper, abundance angle assume than the general, II the for Michalitsianos line atomic s; f Michalitsianos is the characteristic the high-resolution 9 Earth, region emission lines The path there 1980). from 18,200 observations always < s; 1991), The June a Between ratio H expression l'lE estimates obtained line both ratio the ofT.= to Data to line the NE spherical of 1 T. of an T. region II the factor and and is 0 number be T. the equation two length depending is s; appeared ne for geometrical solar 1984). increasing For strengths region ne values If are the and jet are yielded K. of the while III] values understood an nebular 22,500 A 2 ~ by 1980; the region measure our System determining continuum is high-resolution sight 6600-18,000 This 1982 responsible and densities 26,000 with appears line using 9 f semiforbidden overlap electron more found C NE 9 region: length Hollis the through for Throughout abundances x region eta!. estimates et the and obtained A, of is II for a the excitation + (1) value charge 10 spectrum, (Kafatos, May K. Michalit­ constant, line jet observed a!. equal are value and ne emitting emitting electron the A-1666.1) the electron on K, 5 reliable the can NE is square by effects (1988), in These of s; em- to et using up 1980; to is ratio tem­ 0 then pro­ pro­ nA is flux and line 365 NE the the the 10 the the the for for be be (1) jet Z, a!. to be in to in in of III K 0 4 3 • , 1995ApJ...451..359M

70.0 ,----,-----,---..,----,---,,..-~ 12.0,----,---,----,---,------,--, 5e Total UV Flux 1..1..1225-1900 C IV Flux U 1548, 1550 @ > 9 ~ ::::!.

~

> H II region NEJet ...... ,"" 2.4,------,------,------,----.--,-----, 6d § 0 I <•>0 Ill) (0) 0 IV](*) 0 1.) 0 Ill] (0) 0 IV](•) a. r'l e:.. 00 8. ~ '-< •

~ 0 :::. ::... ~ ::... 'Q" ~ ;. ~ 'Z > ~ > ""=t o "= ~=­ .... r'l"" 0.0 __ L___J__..L...__..L._ _ _j______j 0.0 L___.J..__..L...__..J:_ _ _J_ _ __L_ _ _j 0.0 L___..L._ _ __L_ _ __j_ _ __L __ L____j "" 3000 4000 5000 6000 7000 8000 9000 3000 4000 5000 6000 7000 8000 9000 3000 5000 7000 9000 6000 7000 8000 9000 ~ Julian date (+2440000 days) Julian date (+2440000 days) Julian date (+2440000 days) Julian date (+2440000 days) a FIG. 5 FIG. 6 ~ 00 ~ FIG. 5.--{a) Total UV flux (221225-1900), (b) Total UV flux (U2000-3200), (c) 0 I 221302-1306, (d) C II U1334, 1335, (e) C IV H1548, 1550, (f) 0 III] H1660, 1666, (g) N III] H1747-1753, and (h) ;-"" [0 III]+ C II] H2320-2328 absolute fluxes ofthe H II region and NEjet plotted as a function of time. Note the increase in emission-line intensities for the H II region and NEjet as a function of time. Fluxes are in 10- 12 ergs cm- 2 s- 1 A - 1. 9 FIG. 6.--{a, d) 0 I U1302-1306, 0 III] 221660, 1666, 0 IV] 221397-1407, (b, e) Si II 21816, Si III] 21892, Si IV 21393, (c,f) C II H1334, 1335, C III] H1907, 1909 (often saturated), C IV 221548, 1550 low-resolution absolute line intensities ofthe H II region and NE jet plotted against time. Filled squares represent the lowest ionization stage for each element (0 I, Si II, C II); open squares represent the next stage (0 III], Si III], C III]), and the highesi ionization stage is represented by an asterisk (0 IV], Si IV, C IV). Note the close correlation between the line intensities in the NEjet. Line intensities are in 10- 12 ergscm- 2 s- 1 A - 1• 1995ApJ...451..359M cm- 20,000 values yielded sponding to sphere the the nebular (features (d) FIG. C be largest 3 II , L U1334, and should 7.-(a) K, SW NEJet Hn A, a parameters = • • b Region B, values the From Between Between value Jet. 6.3 characteristic ©American ...... T. and or AVERAGE 0 1335 ...... line-emitting = ..... be IV] x diameter D). optical 22,000 of 10 of considered .V.1397-1407 1986 vs. 1982 Notice 14 NEBULAR L for d C line n. 4 4 6 Dec = May = em. IV X X X R ~ (cm- r;:-14.0 ;! S; 0 0 <::.. ~ ~ ~ ~10.0'- ill :e '7 ~ ~ ~ g_ gJ z K ~ "' ~ the " )( )( 250 J.J.1548, ratios 1.5 size of 102c 10 10 18.0 16.0 and 10.0 12.0 14.0 12.0- Aqr 12.01- 16.01- 14.0 10.01- 18.0 and 0.0 2.0 6.0 8.0 4.0 were 8.0 6.0 4.01- 2.01- 8.01- 6.0- 4.0- 0.0 2.0- 0.0 Values linear 4 5 TABLE region 0.0 3 Astronomical 0.0 0.0 PARAMETERS the vs. x ) pc, as 1989 '::--:~-:-'::--='"=-='-=-:-:--:-~::-:-:-::-:-~:-:--:-~ ,-----..,.---,---,----,---,-~ 1- ,----,---,--,------,--,---,---,--., L__ of f­ f- '-----'----'--'------'--..L___j 1983 (Hollis can 10 0 2.0 1550, lower _ substituted the relationship 5.0 n. disk). III] Jun. ~26,000" 15 2.0 Dec. be .. _t_ of of 4.0 3 33,ooo• 18,000 19,000 = ... eta!. J.A1660, region T. 10.0 (e) em 0 N _ C found the d x 4 (K) limits. 6.0 Ill] IV] Si Ill] FOR With 4.0 = __j_ ... 1991). UV 15.0 for :$ I II (A.A.1660, H (A.A.1907, (A.A.1483, 8.0 250 10 _ between R 1666, J.1816 b (e.g., in II in the 5 20.0 AQUARII 6.0 _l_ A 10.012.014.016.018.020.0 fu TEMPORAL . . region Tables em- pc, equation Society (b) _ summary 6.3 1.5 = the vs. 1666) 1909) 1487) 25.0 NE • L(cm) the N ___j_ 1 n. 8.0 X X Si • 3 III] diameter , successive 10 and 10 _ was 30.0 = III] jet. flux flux flux and 3 14 15 ).).1747-1753 _ __jl_____j and x 6 10.0 J.1892, (1) •• 35.0 . corre­ found These of _,____j • T. 1 4. and • 10 the 7b VARIABILITY ionization . = 12.0 7c 40.0 Provided of - - - - (f) ------4 Si ~ g_ ~12.0 "' "' "' .,f (.) ~10.0 ::. ~ i:ii co <::.. vs. ~10.01- §' "' i:ii )( ~ ~ ~ ~ 14.01- 16.0 18.0 IV 12.01- 14.01- 16.0 0.0 8.0 6.0 2.01- 4.0 N 5.0- 6.0- 8.0 7.0- 4.0- 3.0!- 2.01- 0.0 1.01- 8.01- 6.01- 2.01- 4.01- 0.0 0.0 J.1816 stages. M 0.0 IV] 1- 1- 1- 1- 1- c- ,------,-..,----;---,--,---,--,-----, ,-----,--...,----,--,----,:- L___l_ U1483, 5.0 ~ 2.0 by I I vs. . Fluxes I _ 10.0 Si I OF the ~ C _t____L 4.0 n H NE I 1487, IV Observation 15.0 TiME IV • 1979 1982 1980 1991 1986 1983 1990 1992 1987 are 1989 1986 1986 1982 Si I Si Saturated J.1393 (A.A.1548, Jet: M Region: 6.0 NASA R Ill] I 20.0 _ in IV (c) EVOLUTION . . Jan Oct Jun Nov Oct Jun Dec Dec Dec Oct Dec May May I (1..1892) AQR (1..1393) 10- _j__J....____j_ C M1M1~1~1M 8.0 low-resolution 25.0 I I II 1 4 5 27 27 ...... 3 26 13 29 13 I 8 1550) L 25 7 J.J.1334, line 10.0 ...... Date ergs ...... 30.0 ...... AND flux I flux .----.-7"71f ...... I ...... Astrophysics I ratio. flux 12.0 OF em- 35.0 n. TABLE I 1335, _ I 1HE FOR 40.0 2 14.0 .. __j____j • 6.02 emission-line s 1.16 I I I -I NEBULAR vs. R 7d L(cm) 7e 45.0 .­ 5.90 6.98 6.70 6.35 4 16.0 1.83 1.67 A------AQUARII - - - ~ ------C X X III] 10 10 1 . 14 15 U1907, PARAMETERS Data fluxes n, 9.0 6.0 (em_,) 1909 5.0 3.5 2.0" 3.0" X of X System 10 10 the (often 5 4 R Aqr saturated), NE 367 jet 1995ApJ...451..359M (Anandarao and outburst, in 250-300 maxima visual provided determine ation a"' Vogel, path between section.AssumingM (Spitzer and Mira 368 ne region Stromgren or FIG. The The "' the white 2.7 a maxima. x 4 length light is 8.-Visuallight magnitude 44 1928 visual surrounding number properties & x declined 1978), no ©American 10 by dwarf R the yr 10 has and sphere. a 0 Paresce 5 of & longer 14 the orbital 3.3. em- region Mira (Kafatos value 1935 increased Pottasch However, the where em. 3.4. of was AA by Properties between 3 of and ionizing H With curve This and present. the Properties VSO has 1 binary 1992) "'2 (Whitelock calculated II the for the we "'2M region. of binary 1986) calculated & T., maintained by steady mag, value Mira in Astronomical assumed 387 (Fig. the L\mv = photons 2 and Michalitsianos period, of 0 the A day mag, 20,000 for increase ,M possibly the of semimajor From star is 8), variable ais has radius = using Mira :I 12 12 10 :~f 10 12 10 10 ::1:::;\_:-:::' 1 the et 8 6 8 6 6 mid-1970s the ~c---~,~-,----,----,--~5000~-.-,----,----,----,---oo~~ ;4~4 :coo~--,---,----,----,---~sooor----,---,----,----,~~~ 8 ·~. a 0000 0000 0000 0000 238 242 240 239 243 comparable 2 Mira ~ the 6-12 .. values J suggesting that ------,...!.950------1...!.96-0 .... . containing "' ' al. Kepler's l temperature • • i • .,•,.• needed Secondary , ~\ K, variable M7 almost ~ 1970 \ in the ;;_ \'::-J-'_1_~ 1 M • ' , . 387 the • • ' visual • \ indicating lr' : 1983). and , \1 the the rl I mag. • are ~ " ,: III ~ historical • 1890 ·\ • for • 0 . . \t ' Stromgren day axis J_ . ( .. been Orbit in ._ Society number (Wallerstein light l 1982; Mira. \ H to • _\ \J constant the presented •• the law ,_· ., ·' R I' ' ·; that Since Since to 1810 A 1920 I _l , a II lt •...:1,1!'-r~J!.'....;;: ionize • Aquarii Mira : • since • :t J ' of hot H S • minima region estimated \ the ..[ "r was ; obscuration of .. • i ' the .... Burgarella, light • II ... ' ' '\•' ,: ; the 1840 the ,,_=_· 1978. of • 1978, r~ MEIER ~ subdwarf , •• region emission \ varies ~ 2800 from ·r • the \! minima relation used obscur­ v,_~__:.J:._i-,, • · hydro- in . , . . . I '\ r ? .... 1930s is , curve 1986) .; orbit I' . .•. H .. and 1811 Provided • this • 1670 \; ~., the the r \ R " "( to at in 1 · K ~ 1980 of • :':,: :1 Aquarii 1 II · "· ' ~ =-"'-' : I & \ to ;. .. • A .• • ·~ ., \.! ~ -c ~_\._\, 5000 5000 ; 5000 5000 5000 1987 ~ 1900 '1 KAF ~ :- IIA•&"'-;, I l I \ • 181 'f \ \ • '( ; ' __ peratures izing nebula. nosity values number body stellar L*, found gen the number to ~. , ;, "• ~ . 1-1987 .,..v-- \ \ (AAVSO .; \_._\_:_,_:_· Hummer 1820 ; 1930 ~ ~ 1 ionize l_ ATOS . \ I '• ~ by energy ~ ionizing ! the I' A \. :• -., photons formulae ~, 'J to of were ...... ·v models i the Table ' of of ~ 1850 radius ~ ~ be .; data, the I (T* the photons :' • :\I · ------AA-VS-0 • r I ..•. photons ionizing PARAMETER emitted .; ~ ------2::-:!45 N,{H • "'- then NASA • & secondary photons Values • kindly = ~ {I H ! HoT ~ 5 1680 • :~. Ni . : ·:,'- • \.·J (Allen \ lists and is 50,000 Mihalas ; . II y required • I . ., t • used r) ' , .... \ ~ • COMPONENT • •,: (hv region ' 1f not provided . based = by ~ " , • photons that \ r. .. ",; EFFECTIVE \ ; , . 1910 these ' luminosity t• " , Astrophysics : Ni , ~ •• ! .• or \ to \I.\ 1976) the " K ~ \ I lr ... V I· greatly . to are on 13.6 · ., arise ~ (hv \ : T* ~'&1 determine and Lyman ~ (1970) (i.e., . Y 1830 1940 ionize l values .I ; t I '\ central . by .• A ·. the ~ . \ . = • ~- consistent TABLE \1 .:- 'V ~ PARAMETERS (beyond 0.05 0.003 -l l were TEMPERATURES i:: t: J. -12 -12 -: t 0000 0000 240 239 0000 0000 243 241 eV) 244 · 50,000 100,000 from number 00 2 features 8 6 8 8 6 Mattei). 10 10 13.6 6 12 12 10 :: 10 the different of at two determined continuum required H star utilized 5 e K a the whether II VALUE. V) of blackbody. region. Note the K) with is Data Lyman C FOR = secondary different T* for 1 in Lyman T* 3.2 , the from ASSUMED to C = to the the the the 0.04 0.001 outburst 2 photons 100,000 continuum estimate x that System , photoionize number A, far-UV, central 10 the size Since effective limit) 42 and the star. K that and s - estimated required Vol. R* most A') in star. 1 overall of occurred black­ . These lumi­ their tem­ ion­ and was the 451 of 1995ApJ...451..359M (1974), ships from culations accretion accretion that tions 100,000 tional unreasonably No. state (assumed emission, emits 10 of This white mate ward upper perature photoionization ionizing K radius A-1640 hot star & Our determine a!. consistent calculated method cx(n), 20,000 Bacx than ponent underlying T* Alternatively, For The 5 The for Michalitsianos the ~ 1992), K. surrounds component 1, calculations has transition, the of the are the the method 50,000 derived as F(A.1640) of limit dwarf. the argument results of line 1995 He temperatures K and lowest ionization from K a G radiation boundary-layer 228 effective F;. most R* a numerical of parameters. for assuming disk stellar) is 4 blackbody hot but II the ©American above. with (upper (T), for intensity temperature Tylenda continuum K the A-1640 that ~ free-free the A from However, small effective by depends star. and the recent for the (Michalitsianos it 10 = 3.5. and the the (He by the hot of H that yield at 8 is 13 temperature Bath the The of limit), 1982). secondary hot is · symbiotic em. Table modified its II the that photoionizing The recombination R radius Accretion the in value the this number II a is (1977) star (Pottasch region, and estimate Tb x The T* observed component inner value Aqr stellar an temperature secondary, Lyman agreement 1 divided 10 on et same the at electron we resultant of system accretion = We the 5 is free-bound effective can _ only of for a!. provide Astronomical 40,000 A-1640 the 50,000 nebula may 11 believe are close Zanstra boundary we of relevant star. conclude the continuum, of wavelength stars. Disk (1974), the cx(3) cx(2) of of be eta!. continuum assumption T* 1984). by (e.g., intensity used used blackbody ionizing temperature. the be T* integral to in effective determined radiation hot the disk, may obtained with temperature (ehv/kT* K Parameters absorbs K evidence coefficient the T*: that 1980; - Moreover, slightly R hot Kafatos method emission. the - ;;:; to In corresponding (lower secondary Lynden-Bell star, 40,000 that Aqr layer 50,000-60,000 underlying with UV have previous T* this component. estimate following T* then photons (Murset of Kaler used _ limit) temperature ;;:; providing because all if made may continuum that, here = a TEMPORAL 1 method, region. higher, the limit) eta!. Society was the 60,000 )T3G a K for temperature radiation from Assuming 100,000 the This in of we nebular * 1981; (Burgarella star arise is in and He origin in the estimates used the T* the et implied 1986) equation 4 - continuum and & still the estimate the obtain (T) these the The is since The a!. K 10 relation­ ~ II the an nth from the Kafatos various Zanstra K Pringle a to overall K case 42 60,800 higher · short­ and arises A-1640 of of is 1991). • 7;, He small addi­ com­ T;, rela­ He tem­ than level esti­ cal­ is star one 1 s- hot the the the Tb an an Provided VARIABILITY ( = = of of to et 2 is II II a a 1 1 ) jet by have star Figures tions in (hv should l:,.NJN actual Lr yr- where photons for for line The tables the the by Ni are ary disk/boundary itself type mated uncertainties, boundary obvious order dwarf. radius x The The The From factors observations large 10 = calibration is ~ presented secondary, 1 the layer the intensities efficiency R by main size is 38 and provides been 3.2 required 13.6 the {3 of Lr/LEdd M_ properties R* Ld of complete total R* The Aqr theoretical if (M/M the in = be strongest line-emitting f3 3a-3d ...... • L~:d uncertainties, the that from (L0) the the blackbody of magnitude (R Values OF x L conclusions 8 3/:,.L/L ~ of total Table is sequence-star. eV) PARAMETER layer taken accretion increasing (M 0 results 10 the has UV is 2.6 ) 2-3, the ...... source ACCRETION to calculated 4. ~ 0 NASA 0 ...... ·· in the 42 R since and emitted the the then of ) which ionize Ni · errors layer yr- based accretion 4.95 luminosity · (1982-1989), been DISCUSSION X flux ergs Table set ·· radius temperature for AQR s - 6 as and of secondary lines · the is results photoionization, 1 Stromgren 10-5M* in · Table indicates ) · 1 the of ..... · estimates used of the the the Ni. functions, on , and x rate providing · smaller s- Tables · analyzed. emission-line region are of and over the ·· IUE accretion. 6. from DISK Astrophysics the since the 10 H ionizing and . 1 . · of . . number Therefore, absolute our values emission-line Under disk. onto is n 2B. subject in -4M;1(10~biK)[ to number obtained the region. signal-to-noise photoionizing ( PARAMETERS (disk+ TABLE the the ultraviolet Tb, the Tables ultraviolet -10%-15% 105b!K 5 calculate L star 4.9 the 3.2 1.2 AND that than the Over relation. and of T. secondary, to the = La the are Eddington of last boundary In source. X X X 0.04 the 0.04 40,000 of UV of relative Tb to within Assuming in emission-line 10- 10- 10- is secondary, the R* )3/2[ 6 CONCLUSIONS boundary the 6 ionizing this the the Lyman Lyman intensities 1 derived 5 then assumption decade, uncertainties accretion indicate the = R 5 6 continuum 10 and FOR and secondary K spectra corresponding values the intensities time Aqr 100,000 This observations VALUE" section, !~ luminosity Data N{H a it errors continuum R flux M for 6 layer,! ratio. factor luminosity, is number L* continuum 1 AQUARII radiation, 1045 from cannot 7;, are period ~~~~ calculation _ as M that approximately layer), 2.3 3.8 1 M in l.Ox10-11 the 8 increased I) were disk = of in * System = can subject K, flux *is the of Tables 0.03 0.006 J-112 are X X 100,000 flux The = the of is is if Table in weaker the of 1 M/10- 10- 10- an ) photons 1 of the the 1 found parameters of the the of be interpreta­ a be ], the 3-5 related LEdd is are -4%-5% symbiotic increased 4 6 estimates accretion IUE observed M and size hot the photons ionizing and a affected K hot seen derived mass 5 to bound­ by NE given. results 6, 0 of 8 solar­ and = lines. froll) for disk, IU sub­ esti­ M NE it 2-3 star and f3 369 the jet 1.3 by an in of is is E 0 6 a 1995ApJ...451..359M , ~ , jet ing material addition, excitation. of an could condensations Hack Michalitsianos Figures most high-resolution HST function 370 excitation expanding dilute increasing the temperature-dependent tinuous hot NE from from flow combined evidence of does day detection ity 15 line temperature vides region wind separated exhibit ti}.e the that while tionary rate unable precessing by because line Mira Paresce UV 1242 times. ;(; Our The The 65,000 the the is AU plots accretion with NE -1.5 star NE intensities highly pulsation intensities flux and over the continuous at not likely the and evidence an and emanating FOC the (1944) emission (see gas UV Moreover, elevation have is of far-UV a to jet. a and 5a-5h Mira condensations the & or direction. from plotted accretion the K. clearly SW of vary trend Mira ©American from the of times SW becoming constant hot is the below). of He wind. produce (see mechanism observations conditions system This Hack as collimated a originates Moreover, observations collision highly declining. highly found material time. bipolar period formed of the jets is secondary counterjet Mira, the II disk period the on indicate in that emission-line in of Table and in 1982). of intimately results observations between shock A.1640 and in the show as Finally, from the (1994) matter, the high-excitation increasing the a shocked the in Mira disk. excited However, Further which rate, the that the collimated such a the around 386 of larger, placing highly of wind NE gas which jet of SW function 4), from The from emission-line in In jet. may the associated the IUE that N may in source that indicate two other line ratio of overflowed the in day may the which is would consistent An is jet a the addition, 1989 by i.e., is jet, v the Astronomical both far-UV accretion from connected due contains IUE We matter, which an decreasing regions region well-collimated earlier collimated. and this inherently Mira. the observations NE FOC the be have a form decreasing it the alternative Paresce emission period ratios, fact be provide features on from accretion is T, shock mid-1970s of well December stream to believe would produce occurring the spectra far-UV consistent UV an jet He may directing that the hot time indicate that been shock-driven calculations two with emission as Therefore, temporal expands observations mass the accretion it with the with is within its they II fluxes NE or disk continuum 386 other et the is to indicate could fluxes a component highly strong with A, in the winds of be in line-emitting region unstable increasing Roche this any this hot al. emission and disk. the the energetic model an and and ejection ionizing a determined intensity, stellar material Figures B, collides indicative 1982-1989. day and that its NE in near and decreasing with (1991) hand, the time. even system. multiple and secondary, flow far-UV scenario lines variability primary and argues temporal Society produce collimated are An we disk highly evidence SW the the lobe jet a the binary pulsating 1991 total using material is a winds wind becomes by and do more periastron accretion The in D region colliding, events. have model of found 5a-5h temperatures jets v N at is proposed with line-emitting NE collides extending stellar temperature (Kafatos argues and If (Solf emission that this not Paresce increasing, collimated the a of of integrated May. that would emission­ source This emission­ MEIER a from the constant 7;,. emission orbit. provides from variabil­ unstable jet declined that outflow to plots the A.A.1238, the formed bipolar believe NE • for widely collid­ clearly that within a higher These 1992). If more Mira most wind form for con­ as with pro­ C disk The sta­ one L Provided 386 the the the the the jet by be In as in & & in in of is is II a a & KAF v N 1988), jet. point from evidence observations declining, X-ray regions subdwarf. overall emitting an emitting larger. one ionization is region hot be provide sities (Michalitsianos flow (see and inate increase The A.A.1238, may results passes (1994). excitation, a increased Kafatos the the which peratures sities 1992 from dence dence presented clearly 1983 line ing the temporal increased lines gas V. radiative increasing In Alternatively, The ~ expansion ATOS unreasonably It by cools. high ionizing direction period and D earlier intensities Kafatos increase may be 300 summary, toward an through source. of are and the is as for that and collides may emission This the of to display ultraviolet in due However, the ionization of the possible 1242 the in accretion et He volume for ionization a increasing. the km region shock be activity expect Table Therefore, variability since by of Observations overall confirming H continuum the the perhaps the previous temperature al. shock is of to bipolar necessary predictions NASA symbiotic II, such expanding II source in be et NE features (Kafatos Solf in of ~ in s- and of collisional an total (1986). with emission-line intensities IUE a region accretion which we excitation. 10 the material al. speeds emission-line 1986 agreement photoionization 1 et UV from 4 collimated is that jet a • expanding and to in (1992) 5 high high may spectra as disk IUE He believe Since show state 1986), al. integrated the a ultraviolet K increasing material may the wind observations result are observations continuum The we observe Astrophysics postshock plots mentioned and October, the The have declining A, II N that as the flux 1988) star et is up stationary states be for NE at line increasing }.1640 believe by of and of that obtained v disk that the B, account ionization the detection al. lower one perhaps feature that emanating of to We a increase a excitation, with NE increased Viotti (Figs. R the jet. in this of "'80,000 Michalitsianos emitting flow and likely rate intensities which several 1995) Michalitsianos, is the was IUE dominant of X-ray the intensities as Aqr UV would believe spectra feature the in also while shocked. a jet, a emitting electron flux ionization Solf(1992), ionization. high-temperature system. of D. material H above, of precessing A previously could the size (1979-1992). for clumps of et 5a-5h) flux by 10" confirm emission by precessing in jet. may circumstellar in of (Michalitsianos II is 40 although distribution and In suggests hundred emission al. features volume intensity, expect by K H the an region from a that the emission-line N IU of A directing Data and and obtained x km However, the excitation (1987) be temperature requiring II indicate in would factors recombination is density The v, there 20" In volume the accretion E increased of provide spirals region electron shock gas emission the s- responsible responsible who that the present which If an et disk matter does mechanism shock other for or Perez, in aperture H A a km System shock 1 photoionization recent found from . presence is accretion consistent is al. NE region Moreover, accretion a An and Figures 11 be found features of during its and a with a may material photoionized excitation s- a region into is spectra. not no a mechanism, has region. region further shock heated. shock (1986) words, (Solf disk, -2-3 jet soft expanding & & analysis, collimated line needed 1 density line intensities may minimum becoming the B emission­ that only has evidence ROSA Vol. indicate Kafatos Kafatos provide the steadily the encom­ of around exhibit for for chang­ of 1979- inten­ X-ray which inten­ in as 2a-2d 1992). inner while A, orig­ been line­ tem­ may with high with over by Evi­ disk disk The N v N soft H and evi­ hot the 451 the the the the the by to B, T is II a a 1995ApJ...451..359M --. 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