F. Surina, R. A. Hounsell, M. F. Bode, M. J. Darnley, D. J. Harman, F. M. Walter
We investigated the optical light curve of T Pyx during its 2011 outburst through compiling a database of SMEI and AAVSO observations. The SMEI light curve, providing unprecedented detail with high cadence data during t=1.5-49 days post-discovery, was divided into four phases based on the idealised nova optical light curve; the initial rise, the pre-maximum halt (or the 'plateau'), the final rise, and the early decline. Variation in the SMEI light curve reveals a strong period of 1.44\pm0.04 days before the visual maximum. The spectra from the LT and SMARTS telescopes were investigated during t=0.8-80.7 and 155.1-249.9 days. The nova was observed extremely early in its rise where a distinct high velocity ejection phase was evident. A marked drop then gradual increase in derived ejection velocities were present. Here we propose two different stages of mass loss, a short-lived phase occurring immediately after outburst followed by a more steadily evolving and higher mass loss phase. The overall spectral development follows that typical of a Classical Nova and comparison to the photometric behaviour reveals consistencies with the simple evolving pseudo-photosphere model of the nova outburst. The optical spectra were also compared to X-ray and radio light curves. Weak [Fe X] 6375A emission was marginally detected before the rise in X-ray emission. The middle of the plateau in the X-ray light curve is consistent with the appearance of high ionization species detected in optical spectra and the peak of the high frequency radio flux.
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http://arxiv.org/abs/1303.6592
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