Two Cataclysmic Variables discovered by MASTER

ATel #6966; O. Gres (Irkutsk State University), P. Balanutsa, V. Lipunov, E. Gorbovskoy, N. Tiurina, D. Denisenko, A. Kuznetsov, M. Pruzhinskaya, A. Rufanov, V. Vladimirov, V. G. Kornilov (Lomonosov Moscow State University, SAI), K. Ivanov, S. Yazev, N. Budnev, V. Poleshchuk, E. Konstantinov (Irkutsk State University) A. Parkhomenko, A. Tlatov, D. Dormidontov, V. Senik (Kislovodsk Solar Station of Pulkovo Observatory RAS) V. Yurkov, Y. Sergienko, D. Varda, E. Sinyakov, A. Gabovich (Blagoveshchensk Educational University), V. Krushinsky, I. Zalozhnih, A. Popov, A. Bourdanov (Ural Federal University), D. Buckley, S. Potter, A. Kniazev, M. Kotze (South African Astronomical Observatory), V. Shumkov, S. Shurpakov (MASTER team members)
on 20 Jan 2015; 18:09 UT
Credential Certification: Nataly Tyurina (tiurina@sai.msu.ru)

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MASTER OT J223820.02+065346.9 - new CV

MASTER-Tunka auto-detection system discovered OT source at (RA, Dec) = 22h 38m 20.02s +06d 53m 46.9s on 2015-01-14.48084 UT. The unfiltered OT magnitude is 17.0m (limit 18.4m). The OT is seen in 3 images. There is no minor planet at this place. We have reference image without OT on 2010-11-02.51777 UT with unfiltered magnitude limit 19.9m.

Nothing is present at this position in any catalogs and AAVSO VSX. There are no previous Catalina Sky Survey detections. NEAT project has 39 images on 17 different nights from 2000 June 20 to 2005 Sep. 12. No previous outbursts were detected. The object is not visible on the sum of NEAT images to the limiting magnitude ~22.5 and on the color SDSS image to ~23m.

Based on the amplitude of variability (more than 5m), MASTER OT J223820.02+065346.9 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/223820.02065346.9.png

MASTER OT J212510.71+333141.4 - new CV

MASTER-Tunka auto-detection system discovered OT source at (RA, Dec) = 21h 25m 10.71s +33d 31m 41.4s on 2015-01-19.49109 UT. The unfiltered OT magnitude is 16.8m (limit 18.1m). The OT is seen in 3 images. There is no minor planet at this place. We have reference image without OT on 2011-11-03.60353 UT with unfiltered magnitude limit 19.0m.

The OT at quiescence is identical to the blue star USNO-A2.0 1200-17898801 (B=19.2 R=19.1) = USNO-B1.0 1235-0533349 (B1=19.28 R1=19.34 B2=19.99 R2=19.85). Color-combined DSS finder chart is uploaded to http://master.sai.msu.ru/static/OT/J212510+333141-BRIR5x5.jpg (2x zoom). There is a possible UV counterpart GALEX J212510.7+333143 (NUV=20.71+/-0.29). Nothing is present at this position in 1RXS, 2MASS, GCVS and AAVSO VSX. This area of sky in Cygnus is not covered by SDSS, NEAT and Catalina Sky Survey.

MASTER OT J212510.71+333141.4 is a new cataclysmic variable, likely a dwarf nova in outburst. Follow up observations are encouraged. The discovery and reference images are available at: http://master.sai.msu.ru/static/OT/212510.71333141.4.png

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