[vsnet-alert 16905] Re: NSV 2026 outburst cycle

Seiichi Yoshida comet at aerith.net
Sun Feb 9 21:30:27 JST 2014

Dear Denis Denisenko,

Thank you very much for your referring to our MISAO Project
observations in your research on NSV 02026!

What a coincident! Youichirou Nakashima operated his survey of this
fieild on Jan. 23, on the same day of the recent outburst reported by
J.Caron and F.Kugel. It was around 14.4 mag on our unfiltered CCD
images with Canon 500-mm f/4.5 camera lens + SBIG ST-8.

NSV02026 20140123.66043 145C Mis
NSV02026 20140123.66317 143C Mis

Best regards,

> J. Caron and F. Kugel have reported outburst of NSV 2026 (dwarf nova
> in Taurus) on 2014 Jan. 23 in [cvnet-outburst 5792]. They have also
> commented: "apparently it has about one outburst per year". Actually
> this star is a very active dwarf nova with a short outburst cycle
> which is not determined yet, almost 80 years after the discovery.
> Since the galactic latitude is only -8 deg, Catalina Sky Survey is
> rarely visiting this area of Taurus, and the coverage is very sparce.
> Yet it is 4.5 deg south of the ecliptic (currently being occulted by
> the Moon every month, last time on 2014 Jan. 13) which takes away
> another ~20% of observations during the lunar conjunctions.
> I have checked MASTER data and found that the previous outburst
> occured just a month ago, on 2013 Dec. 29! It was not reported to
> vsnet-alert because of the flood of MASTER own discoveries in the end
> of the year (32 OTs in two weeks). Additional outbursts had been
> reported to various mailing lists before. I have collected them in the
> table below.
> NSV 2026
>   20121224.056  15.15C  BRT (Eddy Muyllaert)
>   20130102.051  14.94C  BRT (Eddy Muyllaert)
>   20130107.029  17.44C  BRT (Eddy Muyllaert)
>   20130206.999  14.13C  BRT (Eddy Muyllaert)
>   20131205.062  >158CR  J.Caron and F.Kugel
>   20131229.853  13.56C  MASTER-Kislovodsk
>   20131229.883  13.59C  MASTER-Kislovodsk
>   20140123.790   137CR  J.Caron and F.Kugel
> Yet another outburst was reported by Seiichi Yoshida in [vsnet-alert
> 14295] two years ago together with two previous detections in February
> and November 2011:
> NSV 02026
>   20110204.555   148C   MISAO project
>   20111121.609   139C   MISAO project
>   20120226.486   140C   MISAO project
> February-March 2012 outburst was well covered by Ian Miller and Roger
> Pickard (see AAVSO light curve generator). However, it seems to be
> that the orbital period was not measured.
> T. Kato et al., 2012 based on SDSS colors estimate P=0.080d with 87%
> of NSV 2026 being of SU UMa type (9% are left for WZ Sge type, and
> remaining 4% - for the long period SS Cyg type):
> SDSS J052958.81+184809.8 (u=17.59 g=17.55 r=17.18 i=16.93 z=16.79)
> The star is very active on Palomar plates, never being of the same
> magnitude in the same band. (There are 3 blue, 3 red and 2 infrared
> plates plus one Quick-V). USNO-B magnitudes are:
> USNO-B1.0 1088-0074412 B1=18.15 R1=17.07 B2=17.82 R2=15.02 I=16.45
> and GSC 2.3.2 Vmag is 17.28.
> Finally, there is a faint ROSAT X-ray source 1RXS J052954.9+184817
> formally 56" from NSV 2026, but within the error radius (62"). ROSAT
> flux is 0.00140+/-0.0065 cnts/s and hardness ratios HR1=1.00+/-0.40,
> HR2=1.00+/-0.64.
> Nightly monitoring is needed to establish the outburst recurrence
> cycle and the type of this cataclysmic variable.
> Denis Denisenko

Seiichi Yoshida
comet at aerith.net

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