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Two Active CVs discovered by MASTER

ATel #5953; D. Denisenko, P. Balanutsa, V. Lipunov, E. Gorbovskoy, N. Tiurina, V. Kornilov, N. Shatskiy, V. Chazov, A. Kuznetsov, V. Vladimirov, V. Yecheistov (Moscow State University, SAI), V. Yurkov, Y. Sergienko, D. Varda, E. Sinyakov, A. Gabovich (Blagoveshchensk Educational University), A. Parkhomenko, A. Tlatov, D. Dormidontov, V. Senik (Kislovodsk Solar Station of Pulkovo Observatory), 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), P. Podvorotny, V. Shumkov, S. Shurpakov (MASTER team members), H. Levato, C. Saffe (ICATE), C. Mallamaci, C. Lopez, F. Podest (OAFA)
on 6 Mar 2014; 16:16 UT
Credential Certification: Nataly Tyurina (tiurina@sai.msu.ru)

Subjects: Optical, Cataclysmic Variable, Transient

Referred to by ATel #: 8190

MASTER OT J084404.01+794408.7 - new CV

MASTER-Amur auto-detection system discovered OT source at (RA, Dec) = 08h 44m 04.01s +79d 44m 08.7s on 2014-03-05.47961 UT. The OT unfiltered magnitude is 16.2m (limit 17.7m). The OT is seen in 19 images. There is no minor planet at this place. We have reference image without OT on 2012-10-27.80390 UT with unfiltered magnitude limit 18.5m.

The OT at quiescence is identical to the blue star USNO-A2.0 1650-01314855 (08 44 03.44 +79 44 08.6 R=15.6 B=15.0) = USNO-B1.0 1697-0036147 (08 44 03.793 +79 44 09.46 pmRA=30 pmDE=18 B1=17.15 R1=16.58 B2=20.70 R2=18.99 I=16.94). Object was bright on POSS-I plates of 1953 Mar. 09 and 1954 Nov. 26 but faint on POSS-II plates in 1996-2000. Color-combined (BRIR) finder chart is uploaded to http://master.sai.msu.ru/static/OT/J084404+794408-BRIR.jpg (10'x10' FOV).

The object has an UV counterpart GALEX J084404.7+794410 (NUV=20.02+/-0.17). There is nothing at this position in 1RXS, 2MASS, GCVS and AAVSO VSX. This area of sky in Camelopardalis is not covered by SDSS and CRTS.

Based on the UV counterpart and amplitude of variability (~4m), MASTER OT J084404.01+794408.7 is a new cataclysmic variable, most likely a dwarf nova of Z Cam (UGZ) or SU UMa (UGSU) type. Follow up observations are required. The discovery and reference images are available at: http://master.sai.msu.ru/static/OT/084404.01794408.7.png

MASTER OT J190519.41+301524.4 - unusual CV

MASTER-Kislovodsk auto-detection system discovered OT source at (RA, Dec) = 19h 05m 19.41s +30d 15m 24.4s on 2014-03-06.04617 UT. The OT unfiltered magnitude is 15.7m (limit 17.9m). The OT is seen in 10 images. There is no minor planet at this place. We have reference image without OT on 2010-11-11.67322 UT with unfiltered magnitude limit 16.7m. Checking the arhival observations by MASTER-Tunka, Amur and Kislovodsk shows that the star was in the high state during the three years of MASTER survey varying between 15.2-15.8m since April 2011.

The OT is identical to the blue star USNO-A2.0 1200-10461254 (19 05 19.42 +30 15 24.7 R=16.3 B=16.5) = USNO-B1.0 1202-0321874 (19 05 19.411 +30 15 24.74 B1=16.32 R1=15.65 B2=17.84 R2=N/A I=16.39). The object was bright on 1950 June 17 blue and red POSS-I plates, 1983 July 07 Quick-V, 1989 July 07 blue and 1994 July 02 infrared POSS-II plates, but faint on 1987 June 21 red plate. Color-combined (BRIR) finder chart is uploaded to http://master.sai.msu.ru/static/OT/J190519+301524-BRIR5x5.jpg (2x zoom) and comparison of 1st and 2nd epoch Palomar red plates - to http://master.sai.msu.ru/static/OT/J190519+301524-POSS-Red.jpg (5'x5' FOV).

The object has an UV counterpart GALEX J190519.4+301525 (FUV=17.66+/-0.05 NUV=17.46+/-0.04). There is nothing at this position in 1RXS, 2MASS, GCVS and AAVSO VSX. This area of sky in Lyra is not covered by SDSS and CRTS.

Based on the UV counterpart and amplitude of variability (~4m), MASTER OT J084404.01+794408.7 is a new cataclysmic variable, most likely the anti-nova of VY Scl type in the high state. The non-detection in 1RXS can be explained by the low state during the ROSAT mission. Optical spectroscopy and time-resolved photometry are required. X-rays observations are also encouraged. The discovery and reference images are available at: http://master.sai.msu.ru/static/OT/190519.41301524.4.jpg

List of Optical Transients discovered by MASTER

Global MASTER Robotic Net