Hatena::Groupkanatatmp

KANATA ObsLog

2010-02-10

[] Nova Oph 2010 : update

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We performed the spectroscopic observations of Nova Oph 2010 since Jan. 25. The strong features of Balmer series and NaID show the P-Cyg profile with weak absorptions. The FeII multiplet features are also seen in the regions around 5000-5300A. These characteristics suggest that Nova Oph 2010 is classified into the FeII class in its early phase (Williams 1992). The OI 7774, 8227, 8446 also still form the P-Cyg profile on Feb. 5. The P-Cyg profile dominated spectra continue to form for 10 days. It indicates that the ejecta of Nova Oph 2010 slowly evolved and expanded. An emission of the H alpha strongly develops with time. We will continue the spectroscopic monitoring the Nova 2010 Oph.

[] U Sco : update

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We performed the photometric and spectroscopic observations of the recurrent nova U Sco. The light curve show that this object evolved in the plateau phase. The radiations emitted in this stage are composed to the black body temperature from the optically thick wind and the free-free emissions from the irradiations of the accretion disk on the central white dwarf. The spectrum obtained on Feb. 5 shows that an weak emission line appears at 5400A and the emissions of the HeI 5876 and 7065 simultaneously begin to weaken. The weak emissions line at 5400A is thought to be HeII, which had already been identified in the spectra obtained 6 days after the 1987 outburst (Sekiguchi et al. 1988). Such an appearance of the higher excited level line indicate that the optically thick photosphere would recede enough. We will be able to the research the higher temperature regions in the inner shell comparing to that at the previous phase.

[] OJ 287 : Fall down the polarization degree

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The object has kept to be bright state, about V~14.5. The polarization degree of the object in V band fell down from 35% to 5%. The object showed an anti-correlation relation between the flux and the polarization degree in 2008-2009.