■ [Recurrent Nova] T Pyx : light curve
We performed photometric observations of T Pyx in B, V ,Rc, Ic, J, H and Ks-bands. We successfully obtained the magnitude in rising phase due to the monitoring observations had already been begun since the start of the outburst. Despite of the rapid increase of the luminosity, the color index (except for V-Ks) seem to be almost constant.
■ [Recurrent Nova] T Pyx : Optical Spectrum
We performed the optical spectroscopy of a recurrent nova T Pyx. This nova underwent the previous outburst at 45 years ago (see Margaret and Mayall 1967). We identified the emission lines as HI, HeI, CII, OI, CaII and NII. Our identification indicates that this nova is classified into He/N novae. Arai et al. reported that the highly-excited lines form the P-Cyg profile in their extremely early spectrum, while the lowly-excited ones (e.g., H-alpha, HeI etc) do not. Our spectrum exhibits the P-Cyg profile of these lowly-excited lines. We do not find the highly-excited emission lines. This indicates that the spectral profile of T Pyx rapidly evolved since their report. Arai et al. also measured the line velocity of FWHM of 1000 km/s in H-alpha. The low velocity is rare for He/N class novae. We will continue the observations of this object.
We performed the optical spectroscopic observation of a classical nova V5588 Sgr on Apr. 12. The spectrum exhibits the emission lines of Balmer series, HeI, OI, CaII and FeII. We also possibly identified the CII emission line at 7234 A. The identification of HeI and CII indicates that the photosphere of the nova evolved after the earliest report by Arai et al. (CBET 2679). We will observe this object.
We performed the optical and infrared photometric observations of V5588 Sgr (=Nova Sgr 2011 No.2). The light curves exhibit the rapid decline after the luminosity observed at previous observations. They also exhibits rapid reddening comparing to that of the maximum light.
We performed the optical and near-infrared photometric observations of V5587 Sgr (Nova Sgr 2011) since Feb. 3. The light curves exhibit the rebrightening by 0.6 mag during a week. This nova has already undergone the rebrightening three times until this. The first one had a longer timescale of 30 days with the amplitude of 0.5 mag than other two ones. Other two ones show rather shorter timescale within 10 days and sharp variations. This phenomena may be similar to be oscillation seen in O-class novae (e.g., V603 Aql), whose classification is suggested by Strope et al. 2010.
We update the light curves of V5588 Sgr (=Nova Sgr 2011 No.2) in optical and near-infrared wavelength. The V, J and H band light curves show the slight decline, while the Ks-band light curve do not show the significant variation since previous day. This behavior may be a signature of dust formation as seen in V1280 Sco. We will continue the observations.