Classical and Recurrent Novae are the consequences of accretionof material from a secondary star onto a white dwarf. Thematerial is lost through the inner Lagrangian point into anaccretion disk before falling onto the white dwarf. The propertiesof the outburst depend on the white dwarf mass, the massaccretion rate, the composition of the accreting material and thewhite dwarf (carbon-oxygen or oxygen-neon), and the thermalhistory after repeated outbursts. Nevertheless, while we do findsimilarities in outbursts of different novae, the latest studies ofthe maximum magnitude rate of decline (MMRD) for classical andrecurrent novae show that it is a scatter diagram and cannot beused to find the distance to an individual nova.

These figures highlight the IUE studies of ONe Classical Novae:

1. UV data are extremely important for obtaining the nitrogen,carbon, and neon abundances.

2. The simultaneous appearance of [Ne IV] 1602 and 2422 and [NeV] 1575 strongly imply enriched neon in the ejected gases.

3. ONe Classical Novae are found in our galaxy and the LMC withextremely similar abundances.

4. V838 Her 1991 was very depleted in oxygen and enriched insulfur.

SumnerStarrfield,EarthandSpaceExploration,ArizonaStateUniversity,Tempe,AZ85287-1404(starrfield@asu.edu)StevenN.Shore,DepartmentofPhysics“EnricoFermi”, UniversityofPisa;INFN-Sez.diPisa,Pisa,Italy(steven.neil.shore@unipi.it)

In the region below we present UV (and optical in some cases) spectra of 3classical novae for which we have high resolution UV spectra. These are V339Del (2013) a CO nova (Shore et al. 2016, A&A, 590, 123), V959 Mon (2012) anONe nova and V1369 Cen which is of an unknown type and possibly atransition event between CO and ONe novae. In the panel to the right, wecompare the outburst of V339 Del to that of OS And (1986) which was well

studied by IUE (Shore et al. 2016).

ThereareUVhighdispersionspectraforthefollowingRecurrentnovae:

RSOph (IUE)NovaLMC1990no.2(IUE)

TPyx (STIS,COS)

ThereareUVhighdispersionspectraforthefollowingClassicalnovae:

V838Her(IUE)NLMC1990no.1(IUE)V1974Cyg (IUE,GHRS)NLMC2000(STIS,FUSE)V382Vel (STIS,FUSE)V959Mon(STIS)V339Del(STIS)V1369Cen(STIS)

LMC1991– SuperEddingtonfortwoweeksbutitwasaCONovawithanextremelylowmetallicityandfaroutintheLMChalo.

TheDiscoveryofOxygen-NeonNovae:Williamsetal.1985

Shore et al.: V339 Del (Nova Del 2013) during its early evolution

Fig. 8. Line profile of the C II-IV and N II-V resonant transition at the various epoch for which we have contemporaneous opticaland UV observations. See text for more details.

7

1997MNRAS.290...87V

96 K. M. Vanlandingham, S. Starrfield and S. N. Shore

Table 6. Abundance comparison.'

Element this paper b Williams C Andrea. d Nova Her 91· Nova Cyg 92 f

He 2.86 2.86

C 4.23 11.4

N 225.1 664.5

0 14.1:!:::; 36.4 108.0 126:!:4J

Ne 256.4 692.3

Mg 28.9 118.4

Al 149.2

Si 9.0 42.3

S

• Abundances are relative to H relative to solar, with the following values for log (solar): He= -1.0, C= -3.45, N= -4.03, 0= -3.13, Ne= -3.93, Mg= -4.42, Al= -5.53, Si= -4.45. b Average of June 13 and August 19 results. cWilliams et al. (1985). dAndrea et al. (1994). ·Vanlandingham et al. (1996); see Appendix A, this paper. f Austin et al. (1996).

(1985), and hence their results may suffer from the over-exposure problem as well. Their abundance results are also listed in Table 6. Their values are consistently higher than both ours and those of Williams et al.

We can compare our results for CrA 81 to those of another fast ONeMg nova, Her 91 (Vanlandingham et al. 1996), and to a slower (t3=40d) ONeMg nova, Cyg92 (Austin et al. 1996). Both CrA 81 and Her 91 had very fast optical declines and high expansion velocities. Although we were unable to calculate a luminosity for CrA 81 directly, the value derived by CLOUDY shows that CrA 81 exceeded the Eddington limit for a 1-Mo white dwarf, just as we found for Her 91. We can scale our small-aperture spectra to the portions of the large-aperture spectra that were not over-exposed in order to determine an absolute flux. According

to Allen (1964), the UV flux represents approximately 1 per cent of the total flux for a blackbody of T = 3.2 X 105 K. Summing our SWP and LWR fluxes, we find that the lumin-osity of our fit as determined by CLOUDY is compatible with distance estimates obtained from magnitude-decay rate relationships.

CrA 81, like both Her 91 and Cyg 92, has a high nitrogen-to-oxygen ratio, indicating that the underlying white dwarf is massive (Starrfield et al. 1992). Her 91 had an enhanced sulphur abundance, which is also indicative of a high-mass white dwarf. We found no evidence for sulphur in the spec-tra of CrA 81; however, the strongest lines seen in Her 91 were the near-infrared lines of [Si II] 9069, 9532 A, and we have no data for CrA 81 covering this wavelength range. In Table 6, we list the average abundances from our June 13 and August 19 results, along with the values for Her 91 and Cyg 92. We do not include the November 14 results in our average for CrA 81, since these were more uncertain. Analysis of all three nova used the photoionization code CLOUDY; however, the results for Cyg 92 and Her 91 were obtained with CLOUDY 84, while our analysis of CrA 81 used the most recent version of the code, CLOUDY 90.02. CLOUDY 90.02 uses updated values for the solar abundances (Grevesse & Anders 1989; Grevesse & Noels 1993), and in Table 6 we have listed the results for Her 91 and Cyg 92 relative to these new values. Fig. 7 plots our results, as well as those for Her 91 and Cyg 92, and the solar abundances.

Due to the fact that our limited data did not allow us to constrain the density law, filling factor and filling factor law, we were unable to determine an ejected mass for CrA 81. However, due to the similarity between CrA 81 and Her 91, both in decline rate and elemental abundances, we would expect their ejected masses to be similar. Her 91 was found to have an ejected mass of 10-4 Mo'

6 CONCLUSIONS We have determined the reddening to CrA81 to be in the range of O.l::;;E (B - V)::;; 0.3, with the most likely value

Figure 7. Elemental abundances relative to H for CrA 81 (this paper), Her 91 (Vanlandingham et al. 1996), Cyg 92 (Austin et al. 1996) and solar (Grevesse & Anders 1989; Grevesse & Noels 1993).

© 1997 RAS, MNRAS 290, 87-98

© Royal Astronomical Society • Provided by the NASA Astrophysics Data System

IUEandopticalspectrumofLMC1991.ThisCNreachedV~9

This figure is an example of [Ne IV] 1602 and [Ne V] 1572 inV959 Mon (ONe), V339 Del (CO), and V1369 Cen (??), ataround Day 150 after outburst in each Classical Nova. Theionization stratification of the ejecta aids the identification ofthe transition. V1369 Cen is of uncertain type, the neon linesappear intermediate (relative to the CNO lines) and it may be atransitional form. This comparison highlights the importanceof UV observations in understanding the abundances of novaejecta.

A comparisonofUVspectraofOSAnd(1986)andV339Del(2013)

Line profiles of the C II-IV and N II-V resonant transitions for V 339 Del atthe various epochs for which we have contemporaneous optical and UVObservations.

The resonance lines of N V and C IV compared at the lastobservation of V1369 Cen, more than two years after outburst(STIS spectra, 2016 Mar; paper in prep). The absorption featurescorrespond to the same structures noted in the optically thickinitial stages on lines in the visible (e.g. Fe II, Na I). Highlightingthe importance of high resolution, high quality UV observations,these spectra provide the first direct determination of the N/Cratio in the ejecta of a nova in the late nebular stage of outburst(~200). The optical depths of the two, overlapping components(both transitions are doublets) provides an additional constrainton the optical depth of each absorption structure. The stability ofthe features over this time supports the view of a single, ballisticejection for the expanding gas.

Schwarzet.Al.2001