Three New CVs detected by MASTER

ATel #5706; V. Yecheistov, P. Balanutsa, D. Denisenko, V. Lipunov, E. Gorbovskoy, N. Tiurina, V. Kornilov, N. Shatskiy, V. Chazov, A. Kuznetsov, A. Rufanov, V. Vladimirov (Moscow State University, SAI), A. Parkhomenko, A. Tlatov, D. Dormidontov, V. Senik (Kislovodsk Solar Station of Pulkovo Observatory), V. Yurkov, Y. Sergienko, D. Varda, E. Sinyakov, A. Gabovich (Blagoveshchensk Educational University), 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 28 Dec 2013; 17:43 UT
Credential Certification: Vladimir Lipunov (lipunov2007@gmail.com)

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MASTER OT J220627.82+374653.5 - new CV

MASTER-Amur auto-detection system discovered OT source at (RA, Dec) = 22h 06m 27.82s +37d 46m 53.5s on 2013-12-27.42500 UT. The OT unfiltered magnitude is 17.5m (limit 17.9m). The OT is seen in 2 images. We have reference image without OT on 2012-08-09.73652 UT with unfiltered m_lim=18.8. The object was observed by MASTER-Amur on single images on 2012-11-28.416 UT (16.2m) and 2012-11-30.389 UT (16.4m), but was not detected as a transient then.

The OT at quiescence is identical to the blue star USNO-B1.0 1277-0605257 (22 06 27.854 +37 46 53.94 B1=20.25 R1=19.50 B2=20.87 R2=20.10). Color-combined (BRIR) finder chart is uploaded to http://master.sai.msu.ru/static/OT/J220627+374653-BRIR5x5.jpg (2x zoom). There is also an UV counterpart GALEX J220627.8+374655 (FUV=21.37+/-0.42 NUV=20.39+/-0.21).

There is nothing at this position in 1RXS, 2MASS, GCVS and AAVSO VSX. This area of sky in Lacerta is not covered by SDSS and CRTS.

Based on the blue color, amplitude of variability and previous detections MASTER OT J220627.82+374653.5 is a new cataclysmic variable (dwarf nova in outburst). Follow up observations are required. Discovery and reference images are available at: http://master.sai.msu.ru/static/OT/220627.82374653.5.png

MASTER OT J021757.25+310405.7 - new CV

MASTER-Kislovodsk auto-detection system discovered OT source at (RA, Dec) = 02h 17m 57.25s +31d 04m 05.7s on 2013-12-27.71660 UT. The OT unfiltered magnitude is 17.2m (limit 19.3m). The OT is seen in 3 images. We have reference image without OT on 2013-11-04.85105 UT with unfiltered m_lim=19.4.

The OT at quiescence is identical to the blue star SDSS J021757.20+310405.9 (u=20.89 g=21.19 r=20.94 i=21.01 z=20.43). It has an UV counterpart GALEX J021757.1+310406 (NUV=21.80+/-0.15). There is nothing at this position in 1RXS, USNO-B, 2MASS, GCVS and AAVSO VSX. No previous outbursts were detected by NEAT (18 images on 6 different nights from 2001 Oct. 13 to 2003 Jan. 22).

Based on the blue color and amplitude of variability (~4m) MASTER OT J021757.25+310405.7 is a new CV (dwarf nova in outburst). Follow up observations are encouraged. Discovery and reference images: http://master.sai.msu.ru/static/OT/021757.25310405.7.png

MASTER OT J081520.10+174343.7 - new CV

MASTER-Kislovodsk auto-detection system discovered OT source at (RA, Dec) = 08h 15m 20.10s +17d 43m 43.7s on 2013-12-27.75933 UT. The OT unfiltered magnitude is 16.3m (limit 18.2m). The OT is seen in 12 images. We have reference image with OT at 19.5m on 2010-12-09.92807 UT (limit 21.4m).

The OT at quiescence is identical to the blue star USNO-A2.0 1050-05645203 (08 15 20.14 +17 43 44.0 R=19.3 B=18.8) = USNO-B1.0 1077-0190284 (08 15 20.116 +17 43 43.99 B1=19.55 R1=19.47 B2=20.81 R2=19.60) = SDSS J081520.12+174343.8 (u=20.80 g=21.23 r=20.93 i=20.76 z=20.37). It also has an UV counterpart GALEX J081520.1+174343 (FUV=20.71+/-0.21 NUV=20.02+/-0.11). There is nothing at this position in 1RXS, 2MASS, GCVS and AAVSO VSX.

This area of sky in Cancer was observed by NEAT project on 48 nights from 1996 Sep. 13 to 2006 Feb. 24. Object was in bright outbursts on 2001 Dec. 22 (fading by Dec. 28) and 2003 Feb. 10. Comparison of 2003-01-29 and 2003-02-10 images (sum of three exposures on each night) is uploaded to http://master.sai.msu.ru/static/OT/J081520+174343-NEAT-2003.jpg

Object is showing large variability at low state in Mount Lemmon Survey data available at CRTS website. Based on the blue color and amplitude of variability (~4m) MASTER OT J081520.10+174343.7 is a new CV, likely a dwarf nova of SU UMa (UGSU) in superoutburst. Follow up observations are required. Discovery and reference images: http://master.sai.msu.ru/static/OT/081520.10174343.7.png

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