エントリー

Observation

[season] hydrangea

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[nova] Possible Nova in Sco : spectrum

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We performed spectroscopic observations of Possible nova in Sco (PNV J16551100-3838120 located at Ra=16:55:11.0, Dec=-38:38:12.0) using 1.3-m Araki telescope with LOSA/F2 on June 02.68 under a hazy sky. Our spectrum shows broad H-alpha(FWZI ~ 4600 km/s) and O I(777.4nm) on a reddened continuum light. No visible He or Fe II lines exist in our spectrum.  

[season] rainy season

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The rainy season has begun. According to the Japan Meteorological Agency, this year's rainy season began around May 26 in the Kinki region(*), about 12 days earlier than previous years.

(*) The Kinki region lies in western Japan, and includes Osaka, Kyoto, Nara, Hyogo, Shiga, Wakayama and Mie prefectures.

 

 

[dwarf nova] slit viewer image of OT J210950.5+134840

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[dwarf nova] spectrum of OT J210950.5+134840

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We performed optical low-dispersion spectroscopy (range 400-750nm; R~600@H-alpha) of a new variable star OT J210950.5+134840(*) on May 25.67UT using 1.3m Araki-telescope with LOSA/F2. 

Our spectum shows a blue continuum with H_beta and H_gamma absorptions with no significant blue-shifts. No obvious line is visible at the H_alpha wavelength. This suggests that an emission component of H_alpha could be filling in the absorption line. Our result suggests that the object would be a dwarf nova in outburst.

(*) OT J210950.5+134840 was discovered by K. Itagaki on 2011 May 24.

http://www.cbat.eps.harvard.edu/unconf/followups/J21095047+1348396.html

[symbiotic star] V694 Mon (=MWC560): update LC

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This light curve was observed on 2011 Apr 14.

The amplitudes of variability are ~ 0.2 in g', ~ 0.1 in i', and the time-scale is ~ 30min.

[nova] T Pyx : optical spectrum in the rising phase !

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We obtained optical spectra of T Pyx on Apr. 14.478 UT according to reports of the discovery of the new outbrust ("AAVSO Alert Notics 436" and "vsnet-alert"). T Pyx is a recurrent nova. In the 1966 outburst, the object reached ~6mag in visual bands.  The object brighteness is about 11.5 mag when we observed it tonight. Our preliminary spectrum is shown in the figure. The spectrum shows strong balmer (H-alpha, H-beta), He II, N III, and atomic carbon lines. These features are unique.  In ordinary novae or recurrent novae, they show P-Cygni absorption features for the balmer and He or FeII, and other emissions in its early phase of the outburst. But, T Pyx showed no significant P-Cygni absorptions. These features may be due to the remnant gas surrounding T Pyx with a underdeveloped pseudo-photosphere during the very early stage of the explosion.  We continue observations of the object.

[season] Sakura : full bloom

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The cherry trees are in full bloom in our univeristy !  The picture was taken on Apr.12 around Koyama Astronimical Observatory.

[dwarf nova] MM Hya : g' and i' light curves

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We observed MM Hya from Apr. 9 to 12 in g' and i' bands using ADLER. Superhump are cleraly detected (amplitudes of 0.15--0.2 mag) in both bands.

[Otpical Transient] MisV1444 : spectra

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On April. 10, we obtained optical spectra of MisV1444, which was reported its brightening up in [ vsnet-alert 13124 ].  Spectra of MisV1444 show clearlly TiO band features. MisV1444 may be a Mira varialbe star...

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