6. The overall spectral variations

In general, the observed decrease in the emission line intensities between 1978 and 1993 is of a factor larger than three and up to ten for the low-ionization lines (e.g., SiII, CII, OI, FeII, etc.) and of a factor between two and three for the medium-high excitation lines (e.g. OIV, NIV, CIII, etc..).

Instead, the high-ionization lines (e.g. MgV 1324, OV 1370, 1844), which are all characterized by a broader profile, have generally maintained their original strength or have even increased it. Figure 1 (click here) is a plot of the changes with time in the emission intensity for the three kind of lines just mentioned.

  
Figure 3: The changes in the OI UV2 multiplet between 1978 and 1993

It is worthwhile to report that the MgVI 1190 and 1805 lines, absent in Penston et al. (1983) list, have increased their strength from 1983 to 1993 by a factor about three (see Fig. 2 (click here)). Also, a new emission feature observed at 1226.54 Å has emerged in the 1993 spectrum. As pointed out by the referee the presence of a spurious emission feature (hot pixel or radiation hit) near 1227 Å  has been reported by Schoenberner & Drilling (1985) and by Feibelman & Bruhweiler (1990). However, the emission we observe is real because it is present in two different echelle orders and its rather wide profile is unlikely that of radiation hits or hot pixels. We identify it as Fe VII 1226.65, although there is no clear evidence of the other two Fe VII lines at and  Å.

The changes in the OI emissions are remarkable and deserve special comment. These lines are produced by the well known Bowen mechanism by which the accidental coincidence in wavelength between photons of Å and the transition of OI pumps this upper term. In the subsequent cascade the upper term of the resonant triplet is excited and this results in the observed emission lines. Optical depth effects (and i.s. absorption) are severe in these lines and this results both in the presence of anomalous relative intensities in the triplet, and in the appearance of the semi-forbidden Å emission, a transition which has the same upper term as the triplet. In practice, the great optical depths in the photons has the effect of converting these "trapped" photons into photons that easily escape from the nebula. In RR Tel the changes in the 1303 triplet from 1978 to 1993 were dramatic: the total emission intensity decreased from 3.88  in 1978 to a very small value with an upper limit of 0.33  in 1993 (see Fig. 3 (click here)). The semiforbidden 1641.3 emission, instead, decreased much less, from 0.93  in 1978 to 0.43 in 1993, and this gives rise to a remarkable situation whereby of two transitions arising from the same upper level it is the one which is less favoured by the atomic probabilities that is actually stronger. These variations can be interpreted as evidence of higher optical depth in the OI resonance triplet, an indication of an increase in the column density of OI in the emitting region. However,the fact that the sum of the intensities of the 1303 triplet and of the 1641.3 line decreased significantly is an indication of a decrease in the fluorescent pumping efficiency also. Probably this occurs because fewer 1025 photons are available which, in turn, is an effect of the gradual decline in the luminosity of the EUV ionizing source, as reported by Jordan et al. (1994).

Note added in proof: A very recent article by Crenshaw et al. (1996), appeared in NASA IUE Newsletter No. 56, gives a list of 39 high dispersion IUE artifacts. The agreement with our findings is fair: of the 42 such features we have found or confirmed in the range 1160-1900 Å (Table 3a) 17 are in common with the list of Crenshaw. Two artifacts (at 1474.13 and 1757.57 Å) of the 28 listed in ADB and not confirmed in our study are reported by Crenshaw et al. (1990).

Acknowledgements

A. Cassatella is gratefully acknowledged for having lent us an old fashioned tracing of the SWP 20246 spectrum. We thank S. Ferluga and R. Faraggiana for having allowed us to make use of the computing facilities of their workstations.

 

1978 1980 1981 1982

S2247, 180 min S10434, 60 min S15229, 44 min S18371, 20 min

a = S3407, 1.5 min a = S9540, 10 min a = S14727, 25 min

Wavelength b = S3405, 36 min b = S14230, 10 min

CIII 4 1174.93 74.68 0.19 0.53 0.15 0.87 025 0.66 - -

CIII 4 1175.59 75.36 - - - 0.59 - - - -

? 86.49 0.24 0.31 - - - - - -

1199.18 98.95 0.19 1.51 0.22 1.39 0.17 1.07 - -

SiIII 2 1206.51 06.22 0.22 1.15 0.18 1.17 0.18 1.13 - 0.71

OV] 1218.41 18.15 0.24 b 9.63 b 0.24 9.76 0.26 9.40 0.45 7.61

NV 1 1238.82 38.62 0.25 a 27.14 a 0.21 a 25.20 a 0.23 b 26.84 b 0.24 31.25

NV 1 1242.80 42.65 0.21 a 13.67 a 0.22 a 15.20 a 0.25 b 16.11 b 0.21 15.40

CIII 9 1247.38 47.11 0.34 0.14 0.29 0.37 - - - -

? 49.81 - - 0.26 0.18 - - - -

SiII 4 1264.74 64.66 0.19 0.08 0.34 0.18 0.27 0.20 - - + 1265.00

OI 2 1302.17 01.93 0.22 1.41 0.17 0.65 br 0.23 0.92 br - -

OI 2 1304.86 04.69 0.17 0.30 0.12 0.39 0.11 0.12 - -

OI 2 1306.03 05.81 0.21 2.16 0.21 1.79 0.20 1.32 0.11 1.52

? 09.32 0.30 0.12 - - - - - -

1324.45 24.24 0.32 0.33 0.29 0.50 0.24 0.34 - -

CII 1 1334.53 34.22 0.18 0.29 0.30 0.32 0.15 0.19 - -

CII 1 1335.66 35.40 0.29 0.45 0.19 0.31 0.22 0.37 - -

OIV 1338.61 38.32 0.33 0.14 0.31 0.14 0.20 0.15 0.14 0.32

OIV 1343.51 43.24 0.21 0.32 0.13 0.38 0.24 0.43 0.17 0.81

NII 1345.08 44.67 0.12 0.11 - - - - - -

FeII ? 1360.23 59.87 0.21 0.16 0.14 0.12 0.15 0.12 - -

1365.25 65.08 0.17 0.13 0.23 0.07 br - - - -

OV 7 1371.29 71.02 0.32 1.33 0.34 2.58 0.30 1.38 bl 1.9

SiIV 1 1393.76 93.53 0.23 b 6.64 b 0.26 5.05 0.22 5.12 0.20 5.15

1397.20 96.98 0.22 0.65 0.19 0.60 0.21 0.45 0.22 0.38

1399.77 99.51 0.18 b 1.81 b 0.15 1.42 0.22 1.56 bl 1.10

1401.16 00.89 0.22 b 8.37 b 0.20 7.33 0.23 7.45 0.21 7.15

SiIV 1 1402.77 02.54 0.21 b 2.96 b 0.20 2.57 0.24 2.50 0.17 2.04

1404.81 04.52 0.22 b 4.73 b 0.20 4.56 0.20 4.10 0.17 3.61

1406.06 05.81 0.20 0.51 0.18 0.45 0.18 0.30 0.14 0.31

1407.39 07.13 0.25 1.34 0.21 1.30 0.24 1.10 bl 1.17

NI 10 1411.93 11.63 0.17 0.35 0.12 0.19 0.15 0.18 - -

FeII 68 1413.71 13.47 0.18 0.20 - - 0.33 0.15 - -

1416.93 16.64 0.20 0.35 0.22 0.35 0.15 0.22 - -

1423.89 23.71 - - 0.19 0.19 - - - -

1467.44 67.22 0.24 0.06 - - - - - -

1483.23 82.96 0.24 0.41 0.23 0.33 0.20 0.31 - -

1486.50 86.23 0.21 b 9.49 b 0.23 a 8.24 a 0.22 8.20 0.16 6.94

OV 64 1506.76 06.58 0.25 0.17 0.35 0.18 - - - -

SiII 2 1533.43 33.13 0.34 0.24 0.67 0.21 0.29 0.42 - -

CIV 1 1548.20 48.01 0.27 a 66.55 a s s s s s s

CIV 1 1550.77 50.59 0.26 a 35.40 a 0.28 32.8 0.29 b 31.51 b s s

1574.80 74.39 0.32 2.95 0.30 2.86 0.30 2.55 0.77 2.46

CIII 12.03 1576.49 76.35 0.10 0.041 - - - - - -

CIII 12.03 1577.32 77.14 0.19 0.14 - - - - - -

1601.49 01.22 0.34 b 1.88 b 0.35 1.82 0.34 1.75 0.77 1.63

HeII 12 1640.47 40.18 0.39 a 30.70 a 0.38 a 33.93 a 0.38 b 30.39 b s s

1641.31 40.98 bl 0.24 a bl 0.93 a 0.16 0.95 - - - -

OV 66 1643.62 43.27 0.46 0.20 0.45 0.44 0.49 0.31 - -

1660.80 60.50 0.21 b 2.57 b 0.21 2.35 0.22 2.11 0.15 1.59

1666.15 65.84 0.20 a 7.60 a 0.23 a 6.46 a 0.22 a 5.95 a 0.21 5.57

Al II 2 1670.81 70.27 0.19 0.31 - - - - - -

1698.61 98.20 0.32 0.06 - - 0.14 0.08 - -

FeII 84 1708.24 08.01 - - 0.65 0.12 0.46 0.10 - -

? 10.01 0.40 0.04 - - 0.17 0.03 - -

FeII 1713.21 13.20 - - 0.58 0.13 - - - -

NIV 7 1718.55 18.23 0.45 0.27 bl 0.30 0.47 0.30 - -

SIII 1728.96 28.57 0.23 0.12 - - 0.31 0.14 - -

NI 9 1742.72 42.47 0.16 0.03 - - - - - -

NI 9 1745.25 44.86 0.28 0.08 - - - - - -

1746.82 46.54 0.28 0.12 0.25 0.09 0.24 0.97 - -

1748.65 48.37 0.26 0.43 0.28 0.38 0.22 0.32 0.36 0.35

1749.67 49.36 0.24 b 1.77 b 0.22 1.85 0.22 1.59 0.16 1.47

1752.16 51.86 0.28 b 0.72 b 0.22 0.72 0.24 0.59 - -

1753.99 53.64 0.26 0.37 0.22 0.41 0.25 0.28 - -

 

0

1978 1980 1981 1982

S2247, 180 min S10434, 60 min S15229, 44 min S18371, 20 min

a = S3407, 1.5 min a = S9540, 10 min a = S14727, 25 min

Wavelength b = S3405, 36 min b = S14230, 10 min

? 61.42 0.32 0.11 - - 0.39 0.06 - -

OIII 1768.33 67.93 0.27 0.03 - - 0.21 0.03 - -

FeII ? 1776.63 76.31 0.43 0.33 0.32 0.22 0.31 0.27 - -

FeII 191 1785.27 85.03 0.49 0.12 - - - - - -

FeII 191 1786.74 86.55 0.27 0.01 - - - - - -

FeII 191 1788.00 87.75 0.44 0.03 - - - - - -

SiII 1 1808.11 07.76 0.27 0.36 0.28 0.26 0.26 0.27 0.69 0.41

1814.69 14.38 0.26 0.19 0.25 0.18 0.23 0.14 - -

SiII 1 1816.93 16.68 0.23 b 0.61 b 0.21 0.49 0.23 0.49 0.16 0.52

SiII 1 1817.45 17.16 0.25 0.11 0.24 0.07 0.22 0.05 - -

? 31.71 0.23 0.25 - - 0.22 0.21 - -

OV 1844.42 43.92 - - 0.24 0.07 - - - -

AlIII 1 1854.72 54.44 0.31 0.32 0.30 0.25 0.35 0.22 - -

AlIII 1 1862.79 62.52 0.30 0.15 0.21 0.11 0.31 0.13 - -

FeII 1869.53 69.26 0.28 0.07 0.25 0.08 0.42 0.07 - -

FeII 1872.64 72.41 0.97 0.10 0.52 0.08 0.62 0.09 - -

FeII ? 1881.16 80.93 0.23 0.35 0.22 0.39 0.25 0.30 0.16 0.19

1882.69 82.30 - 0.04 0.16 a 0.02 a 1.5 0.08 - -

FeII ? 1884.11 83.81 - - 0.21 0.53 0.21 0.41 0.23 0.37

1892.03 91.76 0.25 a 5.10 a 0.26 a 4.66 a 0.25 b 5.08 b s s

FeIII 34 1895.56 95.17 0.26 0.04 - - - - - -

 

1983 1984 1985 1986

S20246, 820 min S22531, 40 min S27051, 20 min S29535, 220 min

Wavelength a = S20247, 20 min a = S28741, 20 min

CIII 4 1174.93 74.68 0.13 0.60 - - - - 0.14 0.26

CIII 4 1175.59 75.36 0.24 0.30 - - - - - -

? 86.49 bl 0.40 - - - - bl 0.14

MgVI 1190.03 89.80 0.60 0.49 bl 0.26 - - 0.19 0.58

1199.18 98.95 0.21 0.80 0.54 1.17 - - 0.24 0.73

SiIII 2 1206.51 06.22 0.21 1.05 0.22 0.87 0.25 0.55 0.14 bl 0.56

OV] 1218.41 18.15 0.22 a 7.33 a 0.25 7.73 0.25 7.63 0.21 a 6.77 a

NV 1 1238.82 38.62 0.21 a.bl 31.04 a 0.22 27.66 0.22 26.55 0.23 a 26.60 a

NV 1 1242.80 42.65 0.21 a 14.16 a 0.24 14.17 0.20 12.22 0.21 a 11.13 a

CIII 9 1247.38 47.11 0.20 0.20 - - - - - -

SiII 4 1264.74 64.66 bl 0.11 - - - - - - +1265.00

FeII ? 1265.57 65.33 0.19 0.06 - - - - - -

OI 2 1302.17 01.93 0.19 a 0.85 a 0.19 0.60 0.14 0.63 0.40 0.42

OI 2 1304.86 04.69 0.13 0.18 0.37 0.17 - - 0.12 0.18

OI 2 1306.03 05.81 bl. a 0.97 a 0.23 1.00 bl 0.97 0.23 0.74

? 09.32 bl 0.17 - - - - - -

1324.45 24.24 0.27 0.52 bl 0.24 - - 0.23 0.36

CII 1 1334.53 34.22 0.16 0.20 0.20 0.17 - - 0.18 0.11

CII 1 1335.66 35.40 0.28 0.32 0.38 0.25 0.20 0.18 0.28 0.23

OIV 1338.61 38.32 0.24 0.08 - - - - 0.18 0.09

OIV 1343.51 43.24 0.18 0.20 - - - - 0.20 0.17

NII 1345.08 44.67 0.39 0.10 - - - - - -

FeII ? 1360.23 59.87 0.11 0.14 bl 0.07 - - 0.15 0.12

 

1983 1984 1985 1986

S20246, 820 min S22531, 40 min S27051, 20 min S29535, 220 min

Wavelength a = S20247, 20 min a = S28741, 20 min

1365.25 65.08 0.26 0.11 0.19 0.12 - - 0.37 0.10

OV 7 1371.29 71.02 0.30 a 1.64 a 0.27 1.44 0.22 1.22 0.26 1.45

SiIV 1 1393.76 93.53 0.21 a 4.45 a 0.19 4.21 0.22 3.78 0.24 a 3.07 a

1397.20 96.98 bl. a 0.36 a 0.16 0.53 bl 0.77 0.22 0.45

1399.77 99.51 0.15 a 0.90 a 0.22 0.98 0.13 1.11 0.19 0.85

1401.16 00.89 0.19 a 6.67 a 0.19 6.38 0.20 5.46 0.19 a 5.46 a

SiIV 1 1402.77 02.54 0.17 a 1.88 a 0.18 1.79 0.22 1.69 0.21 a 1.65 a

1404.81 04.52 0.20 a 3.36 a 0.20 3.60 0.18 3.26 0.17 a 3.00 a

1406.06 05.81 0.18 a 0.12 a 0.20 0.33 - - 0.19 0.30

1407.39 07.13 0.19 a 0.92 a 0.19 0.91 0.20 0.82 0.20 0.80

NI 10 1411.93 11.63 0.18 0.21 - - - - 0.21 0.16

FeII 68 1413.71 13.47 0.21 0.25 - - - - 0.20 0.14

1416.93 16.64 0.25 0.36 0.12 0.17 - - 0.22 0.21

1423.89 23.71 0.23 0.13 - 0.05 - - - -

NIII (MgIV) 1470.68 70.34 0.39 0.07 - - - - - -

1483.23 82.96 0.22 0.29 bl 0.24 - - 0.10 bl 0.20

1486.50 86.23 0.18 a 6.36 a 0.19 br 6.83 0.17 6.25 0.18 br. a 5.49 a

OV 64 1506.76 06.58 0.22 0.17 0.40 0.24 - - bl 0.06

? 30.70 0.34 0.29 - - - - - -

SiII 2 1533.43 33.13 0.24 0.28 - - - - bl 0.13

CIV 1 1548.20 48.01 s s s s s s s s

CIV 1 1550.77 50.59 s s s s s s s s

? 65.49 0.28 0.10 - - - - - -

1574.80 74.39 0.22 a. bl 1.89 a 0.27 2.31 0.31 2.01 0.29 2.00

1601.49 01.22 0.30 a 1.49 a 0.33 1.48 0.17 1.32 0.30 1.26

NV ? 1619.74 19.26 0.40 0.13 0.23 0.06 - - - -

? 20.72 0.45 0.14 - - - - - -

HeII 12 1640.47 40.18 s s s s s s s s

1641.31 40.98 0.16 a 0.79 a 0.14 0.81 0.18 0.85 0.14 a 0.75 a

OV 66 1643.62 43.27 0.10 a 0.26 a 0.30 0.25 - - 0.46 0.40

1660.80 60.50 0.22 a 1.69 a 0.21 1.68 0.21 1.62 0.19 a 1.49 a

1666.15 65.84 0.19 a 5.28 a 0.20 5.03 0.19 4.53 0.21 a 4.59 a

? 82.71 0.10 0.05 - - - - 0.15 0.03

1698.61 98.20 0.49 0.09 - - - - 0.17 0.05

OV 67 1707.95 07.59 0.55 0.16 0.94 0.20 0.13 0.20 0.38 bl 0.11

? 10.01 0.14 0.03 - - - - - -

S III 1713.12 12.77 0.35 0.07 - - - - - -

NIV 7 1718.55 18.23 bl 0.27 bl 0.24 - - 0.51 0.22

? 25.02 0.20 0.05 - - - - - -

SIII 1728.96 28.57 0.23 0.11 0.15 0.05 - - 0.20 0.08

NI 9 1742.72 42.47 0.17 0.03 - - - - - -

NI 9 1745.25 44.86 0.22 0.06 0.12 0.05 - - 0.16 0.02

1746.82 46.54 0.22 a 0.10 a 0.55 0.07 - - 0.28 0.07

1748.65 48.37 a. bl 0.31 a 0.20 0.23 bl 0.32 0.18 0.20

1749.67 49.36 0.21 a 1.43 a 0.21 1.24 0.22 1.41 0.20 a 1.15 a

1752.16 51.86 0.23 a 0.63 a 0.18 0.58 0.20 bl 0.85 0.21 a 0.51 a

1753.99 53.64 a. bl 0.27 a 0.22 0.22 0.22 0.24 0.23 0.22

? 61.42 0.30 0.08 0.43 0.12 - - 0.25 0.06

OIII 1768.33 67.93 0.20 0.04 0.18 0.04 - - 0.17 0.03

FeII ? 1776.63 76.31 s s 0.18 0.19 - - 0.39 0.21

FeII 191 1785.27 85.03 bl 0.04 - - - - - -

1805.96 05.47 0.49 0.27 bl 0.16 0.35 0.52 0.81 0.36

SiII 1 1808.11 07.76 0.32 a 0.29 a 0.23 0.23 0.26 0.33 0.28 0.16

1814.69 14.38 s s 0.22 0.14 0.18 bl 0.13 0.28 0.10

SiII 1 1816.93 16.68 0.21 a 0.44 a 0.23 0.41 0.22 0.42 0.22 0.40

SiII 1 1817.45 17.16 s s 0.23 0.07 - - - -

? 31.71 0.29 0.11 0.17 bl 0.11 - - 0.21 0.13

NI 8 1836.74 36.25 0.29 0.01 - - - - - -

OV 1844.42 43.92 0.54 0.10 - - - - 0.34 bl 0.08

AlIII 1 1854.72 54.44 s s 0.27 0.14 0.33 0.12 0.29 0.13

? 59.96 0.54 0.03 - - - - - -

AlIII 1 1862.79 62.52 s s 0.32 0.08 - - 0.32 0.06

FeII 1869.53 69.26 0.27 0.05 0.15 0.04 - - 0.22 0.07

FeII 1872.64 72.41 0.28 0.06 - - - - 0.19 0.07

FeII ? 1881.16 80.93 0.20 a 0.33 a 0.21 0.32 0.28 0.27 0.20 0.27

1882.69 82.30 - 0.10 - - - - - -

FeII ? 1884.11 83.81 0.23 a 0.45 a 0.20 0.43 0.18 0.51 0.21 0.39

1892.03 91.76 0.25 a 3.76 a s s 0.25 3.53 0.26 a 3.38 a

FeIII 34 1895.56 95.17 0.32 0.04 - - - - - -

 

1987 1988 1992 1993

S31081, 127 min S34702, 435 min S46032, 95 min S48188, 120 min

a = S34005, 20 min a = S45214, 20 min a = S48187, 20 min

Wavelength b = S46030, 2 min b = S47600, 15 min

CIII 4 1174.93 74.68 - - - - - 0.24 - -

MgVI 1190.03 89.80 - - - - - - 0.22 1.12

1199.18 98.95 0.18 0.59 0.15 0.57 - - - 0.53

SiIII 2 1206.51 06.22 0.20 0.51 0.16 0.37 - - - 0.35

1218.41 18.15 0.25 6.26 0.27 a 5.18 a 0.25 3.36 0.22 3.39

? 26.45 - - - - - - 0.67 0.93

NV 1 1238.82 38.62 s s 0.22 a 17.25 a 0.21 15.83 0.24 15.10

NV 1 1242.80 42.65 s s 0.23 a 8.20 a 0.20 a 6.24 a 0.22 a 7.22 a

CIII 9 1247.38 47.11 bl 0.16 0.16 0.09 - - - -

? 49.81 bl 0.17 0.59 0.12 - - 0.24 0.42

OI 2 1302.17 01.93 0.38 0.25 0.22 0.18 - - - 0.12

OI 2 1304.86 04.69 0.12 0.11 - - - - - -

OI 2 1306.03 05.81 0.26 0.66 0.20 0.31 - - 0.22 0.21

1324.45 24.24 0.24 0.29 0.21 0.32 0.21 0.24 0.23 0.34

CII 1 1334.53 34.22 0.51 0.20 0.35 0.08 - 0.04 - -

CII 1 1335.66 35.40 0.29 0.18 0.25 0.15 - 0.11 0.21 0.10

OIV 1338.61 38.32 0.18 0.05 0.16 0.05 - - - -

OIV 1343.51 43.24 bl 0.10 0.17 0.13 - - - -

FeII ? 1360.23 59.87 0.19 0.11 - - - - - -

1365.25 65.08 0.14 0.08 0.13 0.07 - - 0.38 0.09

OV 7 1371.29 71.02 0.28 1.50 s s 0.27 1.27 0.29 1.24

SiIV 1 1393.76 93.53 s s 0.25 a 2.22 a 0.22 1.66 0.24 1.79

1397.20 96.98 0.17 0.36 0.19 0.26 0.20 0.29 0.23 0.30

1399.77 99.51 0.25 0.83 0.19 0.72 0.22 0.79 0.23 0.70

1401.16 00.89 s s 0.23 a 3.92 a 0.22 3.94 0.23 4.66

SiIV 1 1402.77 02.54 0.23 1.57 0.24 1.50 0.25 0.89 0.24 0.99

1404.81 04.52 s s 0.23 a 1.96 a 0.20 2.01 0.20 2.25

1406.06 05.81 0.18 0.23 0.18 0.21 0.37 0.18 0.19 0.20

1407.39 07.13 0.22 0.82 0.21 0.59 0.22 0.56 0.22 0.61

NI 10 1411.93 11.63 0.11 0.13 0.34 0.06 - - - -

FeII 68 1413.71 13.47 0.18 0.23 - - - - - -

1416.93 16.64 0.17 0.19 0.17 0.14 0.43 0.15 0.16 0.25

1483.23 82.96 bl 0.23 0.33 0.22 - 0.23 - 0.16

1486.50 86.23 s s 0.19 a 3.76 a 0.21 3.63 0.18 a 3.42 a

OV 1506.76 06.58 - - - 0.08 - - - -

SiII 2 1533.43 33.13 - - 0.16 0.06 - - - -

CIV 1 1548.20 48.01 s s s s 0.29 a 27.48 a 0.26 b 16.31 b

CIV 1 1550.77 50.59 s s s s 0.26 a 15.58 a 0.26 a 14.38 a

? 65.49 - - - - - - 0.27 0.10

1574.80 74.39 0.28 2.01 bl 1.53 a 0.29 1.43 0.29 1.67

1601.49 01.22 0.31 1.34 0.72 1.34 a 0.31 0.97 0.30 0.95

HeII 12 1640.47 40.18 s s s s 0.36 b 14.41 b 0.36 b 15.75 b

1641.31 40.98 0.17 0.60 bl bl 0.12 0.35 0.16 0.43

OV 1643.62 43.27 0.36 0.29 0.41 0.39 0.55 0.36 0.41 0.38

1660.80 60.50 s s 0.19 a 1.17 a 0.23 0.88 0.23 1.01

1666.15 65.84 s s 0.22 a 3.16 a 0.23 2.56 0.21 a 2.90 a

1698.61 98.20 - - 0.18 0.05 - - - -

OV 67 1707.95 07.59 0.53 0.14 0.37 0.10 - 0.08 0.36 0.10

NIV 7 1718.55 18.23 0.22 0.19 0.41 0.19 0.69 0.18 0.41 0.24

SIII 1728.96 28.57 0.18 0.08 0.15 0.07 0.21 0.11 0.26 0.09

NI 9 1742.72 42.47 - - 0.56 0.01 - - - -

NI 9 1745.25 44.86 0.54 0.05 bl 0.03 - - - -

1746.82 46.54 0.28 0.05 0.36 0.06 0.11 0.04 0.47 0.04

1748.65 48.37 0.21 0.20 0.22 0.17 0.25 0.16 0.23 0.15

1749.67 49.36 0.24 1.08 0.27 a 1.11 a 0.21 0.77 0.24 0.87

1752.16 51.86 0.20 0.40 0.19 a 0.40 a 0.22 0.38 0.27 0.33

1753.99 53.64 0.21 0.20 0.23 0.15 0.22 0.14 0.20 0.13

? 61.42 bl 0.15 0.21 0.05 0.26 0.05 0.22 0.04

OIII 1768.33 67.93 - - 0.21 0.02 - - - -

FeII ? 1776.63 76.31 0.54 0.24 0.14 0.15 0.40 0.08 0.14 0.18

1805.96 05.47 0.62 0.38 0.65 0.51 0.60 0.74 0.64 1.07

SiII 1 1808.11 07.76 0.29 0.19 0.32 0.11 0.32 0.07 0.39 0.09

1814.69 14.38 0.25 0.11 0.20 0.08 0.19 0.06 0.20 0.08

SiII 1 1816.93 16.68 0.24 0.30 s s 0.26 0.13 0.30 0.17

SiII 1 1817.45 17.16 0.22 0.06 s s - - - -

? 31.71 0.22 0.08 0.16 0.06 0.19 0.07 0.21 0.07

OV 1844.42 43.92 0.67 0.12 0.45 0.09 0.38 0.11 0.54 0.16

 

1987 1988 1992 1993

S31081, 127 min S34702, 435 min S46032, 95 min S48188, 120 min

a = S34005, 20 min a = S45214, 20 min a = S48187, 20 min

Wavelength b = S46030, 2 min b = S47600, 15 min

AlIII 1 1854.72 54.44 0.34 0.15 0.33 0.08 0.35 0.09 0.56 0.07

? 59.96 - - 0.65 0.02 - - - -

AlIII 1 1862.79 62.52 035 0.06 0.22 0.04 - - - -

FeII 1869.53 69.26 0.21 0.04 0.15 0.02 - - 0.55 0.06

FeII 1872.64 72.41 0.12 0.05 0.15 0.02 - - - -

FeII ? 1881.16 80.93 0.21 0.26 0.21 0.20 0.18 0.20 0.22 0.23

FeII ? 1884.11 83.81 0.18 0.35 0.23a 0.37 a 0.17 0.31 0.21 0.35

1892.03 91.76 s s 0.27 a 2.25 a 0.27a 1.74 a 0.26 a 1.76 a

 

element mult. FWHM Intensity Notes

NeV 1145.60 45.30 0.24 - Jordan (1973)

CIII 1296.33 96.00 0.26 0.08 Kelly (1987)

? 1307.00 0.32 0.08

NIII 1387.30 86.90 0.28 0.10 Kelly (1987)

FeII 69 1413.70 13.30 0.12 0.28 Also in CH Cyg

Ni II 6 1510.85 10.40 0.26 0.04 Also in CH Cyg

SiII 2 1526.71 26.40 - >0.08 reabsorbed

? 1562.20 0.12 0.04

? 1778.30 - 0.03

? 1778.70 0.22 0.05

? 1781.10 0.23 0.03

NIII 1835.31 35.20 0.20 0.02 Kelly (1987)

OV UV75 1845.63 45.30 0.32 > 0.03

? 1899.80 - >0.03 blend

 

Table 3a Table 3b

Confirmed (or likely) spectral Additional artifacts found

artifacts from ADB in this study

1216.35 1160.0 1583.9

1281.62 1165.9 1629.8

1298.48 1266.9. 1691.1

1504.94 1287.9. 1702.7

1536.84 1288.2 1706.9

1603.40 1288.5 1710.0

1603.92 1288.8 1729.0

1604.37 1315.7 1755.6

1692.91 1381.7 1800.0

1718.62 1453.7 1825.1

1725.77 1454.1

1762.21 1454.9

1794.07 1460.7

1795.38 1487.8

1809.93 1500.9

1845.27 1573.0