[vsnet-alert 14772] Re: OT J170609.7+143452 outburst

[Denis Denisenko]

Dear all,

MASTER-Tunka has accidentally observed this field less than 2 hours
ago with 180-sec exposure starting on 2012-07-19 at 14:53:08 UT. The
unfiltered magnitude of CRTS OT J170609.7+143452 is 16.6+/-0.1. This
is well above the quiescent magnitude of this variable (typically
17.7-18.4 with the same USNO-B1.0 Red zeropoint), but well below the
outburst magnitude reported from 2 days old MISAO observation. It
seems the star is already fading after the outburst now.

I have also checked the MASTER-Kislovodsk database, and curiously
enough the discovery outburst of CSS 090205:170610+143452 was observed
by MASTER on 2009-01-24 on three images at 03:29:14, 03:30:50 and
03:32:21 UT at 14.3, 14.4 and 14.7 magnitudes, respectively. But the
automatic transient detection by MASTERs had not started yet at that
time.

The variable was at quiescence on 2012 June 11 MASTER-Kislovodsk
images, as well as on June 08 and June 17 CSS images.

Denis in Moscow

On Thu, Jul 19, 2012 at 7:49 PM, Seiichi Yoshida <comet at aerith.net> wrote:
> Dear colleagues,
>
> We detected that a dwarf nova OT J170609.7+143452 is bright at around
> 14-15 mag at July 17.55(UT) from Nobuo Ohkura's survey images with
> 350-mm camera lens + f/2.8 reducer lens + SBIG STL-1001E in the course
> of the MISAO Project. It was not visible on the images on May 23 and
> June 13.