Interesting Superoutburst of MASTER OT J085854.16-274030.7‏

Affiliation
American Association of Variable Star Observers (AAVSO)
Fri, 01/23/2015 - 04:01

MASTER reported an optical transient and possible CV on the 18th of January see http://www.astronomerstelegram.org/?read=6946

After been alerted by Patrick Schmeer on , I have monitored over a few nights on 2 telescopes and uploaded data to the AAVSO after requesting an AUID from VSX and comparison stars.

 

Results I have to date

Filtered data V

18/1/15  no superhumps visible         13.77 - 13.85 V magnitude  B 13.99  R 13.68  I 13.69

19/1/15 developing superhumps of period 0.0579    

20/1/15 clouded out

21/1/15  superhump period 0.0552   13.95 - 14.25 V magnitude  B 14.28  R 13.89  I  13.91

22/1/15 superhump period 0.0528    14.10 - 14.35 V magnitude  B 14.48  R 14.12  I 14.10

 

Unfiltered data (CV) (higher time resolution)

21/1/15 superhump period 0.0542  14.15 - 14.41 unfiltered magnitude compared to V

22/1/15 superhump period 0.0557  14.3 - 14.55 unfiltered magnitude compared to V

 

amplitude between 0.2 and 0.3 with superhumps well developed on the 21st and 22nd. Hint of them on the 19th and no sign on the 18th but my dataset was too short to see anything.

 

Looks to me like a WZ Sge type dwarf nova.

 

I have been clouded out for a lot of the time, be good for someone to do some time series photometry and possibly spectroscopy though maybe a bit faint for that now.