Hatena::Groupkanatatmp

KANATA ObsLog

2010-04-08

[] S5 0716+714 : Update the data

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We update the data of S5 0716+714. The figure shows the light curve of the object and temporal variation of the polarization degree in the V band. The polarization degree keeps to be high, larger than 10 %.

[] 3C 454.3 : Flare up in 2010 season

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Fermi/LAT detected an increasing gamma-ray activity from the 3C 454.3 (ATel #2534). After this report, we have started to observe the object in 2010 season. The figure shows the light curve in the V band and the V-J color variation. We detected the increasing optical activity from the object. The flux in the optical band has been increased coincident with that of the gamma-ray band. The V-J color showed about the same value at the flare in 2009 season, and about 2.1.

[] Type II SN 2009ls : Confirming the end of the hydrogen diffusion

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We have performed the photometric observations of Type II SN 2009ls. The light curves indicate that SN 2009ls would reached the "secondary plateau phase". For a typical SN, the luminosity should linearly decrease according to the decay of the Co56. This conspicuous behavior was seen in another Type IIP SN 2004dj (Tsvetkov et al. 2008). These results indicate that the diffusion of the hydrogen have roughly finished in its expanding atmosphere, but the layered material may be left in the inner part. If we confirm how long the "secondary plateau" continue, we may estimate the mass and the abundance of the hydrogen (or layered Helium?). The spectra would show the nebular emission lines with weak (or no) hydrogen lines. We will continue the photometry.

[] V407 Cyg : many conspicuous features

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We have performed the spectroscopic observations for the symbiotic nova V407 Cyg. Its spectra show several peculiar characteristics as a classical nova. First, the spectra show the both emission lines of FeII and HeI. In general, classical nova is classified into the FeII or He/N class. Our spectra exhibit the both characteristics. Thus, V407 Cyg may be classified into the 'Hybrid nova' like V458 Vul. The HeII is also possibly seen in our spectra. In general, such a highly excited emission line is come to be seen in its later nebular phase. However, The evolutions of the spectral profile (and the light curve) are rather slow for a symbiotic nova (e.g., RS Oph; Iijima 2009). The behavior contradicts the appearance of the highly excited emission lines. Alternatively, the width of the Balmer series is broadened as > 5000 km/s, but the other lines clearly show the rather narrower than those of Balmer siries. These spectroscopic features are remarkably conspicuous for the classical nova. Although the nova eruption is rarely confirmed in a symbiotic system, a few outbursts of this subclass occur as a recurrent nova (e.g., T CrB and RS Oph). As the photosphere of expanding shell is shrinkage, the inner part ejecta unveiled and the nebular emission lines should reveal. We will continue the spectroscopy for V407 Cyg.

[] Starting Observations of Type II SN 2010bj

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We have performed the photometric observations of Type II SN 2010bj since Mar. 28 (UT). SN 2010bj was discovered of 15.3 mag at 27.05 Mar. in spiral galaxy NGC 2357 by L. Cox (reported in CBET 2230). The distance modulus to this host galaxy is adopted as 32.5 referred in NED/extragalactic database. This SN was classified as a Type II SN around its maximum phase from the spectroscopy at Apr. 6 by Challis et al. (reported in CBET 2232). Our obtained light curve also indicate that SN 2010bj is well similar to that of a typical Type II SN. We will continue the observations of this object until the limited date.