MASTER Discovery of Two Large Amplitude Cataclysmic Variables

ATel #6783; V. Shumkov, D. Denisenko, V. Lipunov, E. Gorbovskoy, N. Tiurina, P. Balanutsa, V. Kornilov, N. Shatskiy, V. Chazov, A. Kuznetsov, V. Vladimirov, E. Popova (Lomonosov Moscow State University, SAI), K. Ivanov, S. Yazev, N. Budnev, E. Konstantinov, O. Chuvalaev, V. Poleshchuk, O. Gress (Irkutsk State University), V. Krushinsky, I. Zalozhnih, A. Popov, A. Bourdanov (Ural Federal University), A. Tlatov, D. Dormidontov, V. Senik, A. Parkhomenko (Kislovodsk Solar Station of Pulkovo Observatory), V. Yurkov, A. Gabovich, Y. Sergienko, E. Sinyakov (Blagoveshchensk Educational University), S. Shurpakov (MASTER team member)
on 4 Dec 2014; 14:28 UT
Credential Certification: Nataly Tyurina (tiurina@sai.msu.ru)

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MASTER OT J184019.38+273958.1 - new CV

MASTER-Tunka auto-detection system discovered OT source at (RA, Dec) = 18h 40m 19.38s +27d 39m 58.1s on 2014-12-03.43150 UT. The OT unfiltered magnitude is 15.6m (limit 17.7m). The OT is seen in 4 images. There is no minor planet at this place. We have reference image without OT on 2011-07-28.68306 UT with unfiltered magnitude limit 19.8m. The object was not present on the unfiltered MASTER-Tunka images obtained two nights ago with the latest non-detection on 2014-12-01.537 UT (limit 17.9m).

There is nothing at this position in any catalogs and on the sum of digitized Palomar plates (limiting magnitude ~22). Color-combined DSS finder chart is uploaded to http://master.sai.msu.ru/static/OT/J184019+273958-BRIR5x5.jpg (2x zoom). This area of sky in Lyra is not covered by SDSS, Catalina Sky Survey and NEAT.

Based on the amplitude of variability (at least 6m), MASTER OT J184019.38+273958.1 is likely a new cataclysmic variable (dwarf nova) in the early stage of superoutburst. Follow up observations are encouraged. The discovery and reference images are available at: http://master.sai.msu.ru/static/OT/184019.38273958.1.png

MASTER OT J061944.87+605917.1 - new CV

MASTER-Tunka auto-detection system discovered OT source at (RA, Dec) = 06h 19m 44.87s +60d 59m 17.1s on 2014-12-03.74514 UT. The OT unfiltered magnitude is 16.1m (limit 19.3m). The OT is seen in 6 images. There is no minor planet at this place. We have reference image without OT on 2012-02-16.66046 UT with unfiltered magnitude limit 20.2m.

The object is not present in any catalogs. A faint blue star (~21m) is marginally visible at this position on the sum of digitized Palomar plates. Color-combined DSS finder chart is uploaded to http://master.sai.msu.ru/static/OT/J061944+605917-BRIR5x5.jpg (2x zoom). This area of sky in Lynx is not covered by SDSS and NEAT. No previous outbursts were detected by Catalina Sky Survey.

Based on the amplitude of variability (about 5m), MASTER OT J061944.87+605917.1 is a new cataclysmic variable (dwarf nova) in outburst. Follow up observations are encouraged. The discovery and reference images are available at: http://master.sai.msu.ru/static/OT/061944.87605917.1.png

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