We have started the photometric observations of Type Ia SN 2010it since Oct. 15. This SN was discovered of 15.6 mag at NGC 1417 on Oct. 11 by Lick Observatory Supernova Search (LOSS). The spectroscopic observations were performed and it is classified into Type Ia SN before maximum. We will perform the photometric observation of this SN.
We update the light curves of Nova Aql 2010 in VRI-bands. The light curves show suddenly a rapid decline in the R and I bands. In general, the decline rate of nova is according to the power-law due to the free-expanding photosphere and its shrinkage. However, our light curves is inconsistent with this interpretation. This rapid decline may be originated from highly opaque material in optical region due to forming dust in the ejecta. If this nova formed the dust, the near-infrared flux will increase up with the decrease in optical region.
We update the light curves of the Type Ia Supernova (SN) PTF10ygu in optical wavelengths. This SN exhibits the slowly rising time comparing to that of a typica SN Ia. This fact indicates that this SN may be classified into the luminous group.
We started the photometric observations of Type Ia supernova PTF10ygu since Oct. 14. This object was discovered of 18.7 mag on Oct 12.5 UT in spiral galaxy NGC 2929 by Palomar Transient Factory. Thereafter, the spectroscopic observation was performed and this object was classified into a very young Type Ia SN (ATEL2934). Despite of the comparable property in the light curve, Type Ia SNe are thought to be classified into two groups based on their velocity evolutions. However, if we successfully obtain the spectra around two weeks before maximum, the line velocity would be very high comparing to that of latter phase. We will continue the photometric observation of PTF10ygu.
■ [Extragalactic nova] M31 2010-09b : update
We update the light curve of M31 2010-09b. We can roughly estimate of the t2 ~ 10, which takes days decrease of 2 magnitude in the light curves. The low decline rate indicates that this nova is a very fast nova, like U Sco, V2491 Cyg, V1500 Cyg and so on.
We performed the spectroscopic observation of Nova Aql 2010 on 2010 Oct. 5. The spectrum still exhibits the CaII IR triplet. This nova may be slow nova. We will observations of this nova.
■ [Extragalactic nova] M31 2010-09b : Observations Start
We performed the photometric observations of M31 2010-09b using 1.5m-Kanata telescope equipped with HOWPol. This nova was discovered of 17.3 mag in the nearby galaxy M31 on 2010 Sep. 30.566 by the amatuer nova survey persons, Nishiyama and Kabashima (CBET 2472). Despite of the early discovery of this nova (ATEL 2896), our preliminary results indicate that the brightness rapidly decrease with time. This results suggest that M31 2010-09b may be a class of very fast novae (Payne-Gaposchkin 1958). But, the object is not so moreluminous than M31 2009-10b (CBET 1971, Kanata ObsLog on 2009 Oct. 19). This means that this nova may be reddened by the galactic dust or a possible candidate of the recurrent nova, like U Sco. Shafter et al. reported that the spectrum exhibits the HeII 4686 line and the FeII line series on Oct. 1.39, which indicates that this nova is a possible hybrid nova (ATEL 2898). This class object will be rapidly fading out. We will observe this object until limit.