Table A.1
Optical spectroscopic summary.
| Date | I-band | Comments | Reference |
|
|
|||
| <1955 | – | Hα, Hβ, Hγ and He ii 4686 Å in emission | Lindsay (1955) |
| 1967 July 14 | – | Balmer emission to Hϵ. He ii 4686 Å absent | Sanduleak (1978) |
| 1972–74 | – | Hα, Hβ, Hγ, Hϵ in emission. No mention of He ii 4686 Å | Azzopardi et al. (1975) |
| 1977 September 17 | – | Balmer emission to Hϵ. He ii 4686 Å emission comparable to Hβ | Sanduleak (1978) |
| 1978 January 27 | – | Hβ to H13 P Cygni emission. He ii 4686 Å and Fe ii (multiplet 24) in emission | Azzopardi et al. (1981) |
| 1978 July 16 | – | Hα to H11 and He ii 4686 Å in emission | Shore et al. (1987) |
| 1981 July 13 | – | Balmer series and He ii 4686 Å in emission | Shore & Sanduleak (1982) |
| 1982 March 22 | – | Balmer series and He ii 4686 Å in emission | Shore & Sanduleak (1982) |
| He ii 4686 Å ~50% weaker than 1981 July 13 | |||
| 1983 Oct. 10 | – | Hα to H11 and He ii 4686 Å in emission | Shore et al. (1987) |
| 1983 December 17 | – | Hα to H11 and He ii 4686 Å in emission. | Shore et al. (1987) |
| P Cygni profile for higher Balmer lines but not Hα or He ii 4686 Å | |||
| 1987 Nov. 7 | – | Hα to Hδ and He i 5876 Å in P Cygni emission. He ii 4686 Å absent | Zickgraf et al. (1989) |
| 1991 September 17–20 | – | Hα to Hδ and He i in emission. Double peaked He ii 4686 Å | Nota et al. (1996) |
| 2000 October 11–14 | 12.52 | Hβ to Hδ in emission. He ii 4686 Å absent | Massey & Duffy (2001) |
| 2000 October 13 | 12.52 | Hα, Hβ and He i 6678 Å in P Cygni emission. He ii 4686 Å absent | Torres et al. (2012) |
| 2001 November 24 | 12.66 | Hα, Hβ and He i 6678 Å in emission. He ii 4686 Å absent | Torres et al. (2012) |
| 2005 December 10 | 12.69 | Hα, Hβ, He i 6678 Å and He ii 4686 Å in emission | Torres et al. (2012) |
| 2007 October 3–4 | 13.10 | Hα, Hβ, He i 6678 Å and He ii 4686 Å in emission | Torres et al. (2012) |
| 2008 November 13 | 12.79 | Hα, Hβ, He i 6678 Å and He ii 4686 Å in emission | Torres et al. (2012) |
| 2010 November 24 | 12.55 | Hβ to Hϵ in P Cygni emission, He ii 4686 Å absent | This work |
| 2011 July 11 | 12.62 | Hα to Hδ, He i 6678 Å and 7065 Å and He ii 4686 Å in emission | This work |
| He ii 4686 Å stronger than Hγ | |||
| 2011 December 8 | 12.51 | Hβ to Hϵ in emission, He ii 4686 Å weakly in emission | This work |
| Hβ single peaked, Hγ to Hϵ P Cygni profiles | |||
| 2012 July 07 | 12.92 | Hβ to Hϵ in (single peaked) emission, He ii 4686 Å stronger than Hγ | This work |
Notes. I-band magnitudes quoted are from OGLE-II,-III and -IV (Sect. 2.1). Note that emission lines are single peaked unless otherwise noted. Lindsay (1955), Sanduleak (1978), Azzopardi et al. (1975), Shore & Sanduleak (1982). Shore et al. (1987) and Torres et al. (2012) do not present all the spectra described in these works. Additionally Azzopardi & Breysacher (1975) detected He ii 4686 Å in emission in 1977 October via an objective prism survey.
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