Outburst of CT Hya

In vsnet-obs 2188, Tonny Vanmunster reports an outburst of CT Hya, which was recently identified as an SU UMa-type dwarf nova. Vanmunster observed this star at mv=14.4 on Feb. 21.947 UT. Daisaku Nogami, Ouda Station, observed this star at V=18.95 on Feb. 23.581. This observation might suggest that the present outburst is over (more than 4 mag. decline in 1.6 day might be too rapid, though ?).

  085108     +030832      2000 CT Hya     UGSU         13.6C-20:P
    (Downes & Shara 1993)
  085107.41  +030833.8    2000
    (from Ouda image)

VSNET chart (revised V magnitudes)

The 1995 Feb. outburst (from vsnet-alert log)

(from vsnet-alert 51, 1995 Feb. 28)

Dear colleagues,

CT Hya is now in outburst, which was first notified by M. Iida, and we (Ouda team, Kyoto University) observed it on Feb. 27 at the Ouda Station using 0.6 m refl. + CCD with Johnson V-band filter. Our observation finally revealed the superhumps with amplitude of about 0.3 mag. in CT Hya and CT Hya was first identified to be a member of SU UMa-stars. The preliminary analysis gives Psh of 0.065 (+- 0.001) day.

Best regards,
Daisaku Nogami

(from vsnet-alert 52, 1995 Mar. 3)

Dear colleagues,

We (Ouda team, Kyoto University) observed DV UMa and CT Hya using 0.6 m reflector + CCD with Johnson V filter. The magnitudes of DV UMa (out of eclipse) and CT Hya are estimated with the maximum counts of CCD images as follows:

stars    date(UT)  V mag.
DV UMa  Mar. 2.63   16.5
CT Hya       2.58   14.4

DV UMa continues to be fainter rapidly (about 0.5 mag/day).
CT UMa is still in superoutburst.

Best regards,
Daisaku Nogami

For more reading

Paper by Nogami et al. (PASJ submitted, TeX file)

Get full texts and figures

Light curve of superhumps (1995 Feb. 27)

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