In 1948 the South African amateur astronomers de Kock and Kirchhoff were the first to notice that RR Tel had brightened to 7th magnitude. Subsequent examination of the Harvard Patrol plates showed that it had in fact reached a maximum in 1944 after rapidly brightening 7 magnitudes (Mayall, 1949). Prior to 1944 the object showed variations with a period of 387 days and an amplitude of up to 2 magnitudes in the blue. After the outburst the spectrum evolved in a manner characteristic of very slow novae: an F5 supergiant absorption spectrum gave way to strong permitted and forbidden emission lines. The ionization levels characterising the emission increased with time. The spectral development has been extensively studied and has been well summarised for the period up to 1973 in the Thackeray’s (1977) monograph on the subject. More recent spectra (e.g. Penston et al, 1981) show that although the trend towards species of increasingly higher ionization has probably stopped, the visual and near ultraviolet light is still completely dominated by strong emission lines with a weak blue continuum.
KeywordsSubsequent Examination Spectral Development Symbiotic Star Strong Emission Line Mira Variable
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