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Two new CVs detected by MASTER

ATel #5586; V. Yecheistov, A. Rufanov, D. Denisenko, E. Gorbovskoy, V. Lipunov, N. Tiurina, P. Balanutsa, V. Kornilov, A. Belinski, N. Shatskiy, V. Chazov, A. Kuznetsov, V. Vladimirov (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 17 Nov 2013; 12:15 UT
Credential Certification: Vladimir Lipunov (lipunov2007@gmail.com)

Subjects: Optical, Cataclysmic Variable, Transient

MASTER OT J235504.61+160854.7 - new CV

MASTER-Tunka auto-detection system discovered OT source at (RA, Dec) = 23h 55m 04.61s +16d 08m 54.7s on 2013-11-16.50865 UT. The OT unfiltered magnitude is 16.1m (limit 16.8m). The OT is seen in 2 images. There is no minor planet at this place. We have reference image without OT on 2011-11-20.53028 UT with unfiltered magnitude limit 20.0m.

The OT at quiescence is identical to the faint blue star SDSS J235504.70+160853.7 (u=22.03 g=21.95 r=21.96 i=22.37 z=21.65). It has also an UV counterpart GALEX J235504.7+160854 (FUV=23.23+/-0.32, NUV=22.11+/-0.14). There is nothing at this position in 1RXS, USNO-B, 2MASS, GCVS and AAVSO VSX.

This area of sky in Pegasus was observed by NEAT project with 43 images obtained on 16 nights from 2000 Aug. 05 to 2005 Aug. 13. No outbursts were detected.

Based on the blue color, UV detection and amplitude of variability (at least 6m) we conclude that MASTER OT J235504.61+160854.7 is a new cataclysmic variable of SU UMa (UGSU) type in superoutburst. Follow up observations are required. The discovery and reference images are available at: http://master.sai.msu.ru/static/OT/235504.61160854.7.jpg

MASTER OT J215433.99+235400.8 - new CV

MASTER-Kislovodsk auto-detection system discovered OT source at (RA, Dec) = 21h 54m 33.99s +23d 54m 00.8s on 2013-11-16.70968 UT. The OT unfiltered magnitude is 16.1m (limit 18.1m). The OT is seen in 13 images. There is no minor planet at this place. We have reference image without OT on 2012-09-13.86490 UT with unfiltered magnitude limit 20.1m.

The OT at quiescence is identical to the faint star SDSS J215433.96+235400.3 (u=20.96 g=21.31 r=20.86 i=20.37 z=20.04) and USNO-B1.0 1139-0532385 (21 54 33.942 +23 54 00.69 pmRA=-22 pmDE=-26 R1=19.78 B2=21.10 R2=19.93). It has also an UV counterpart GALEX J215434.0+235400 (FUV=18.74+/-0.07, NUV=18.68+/-0.05). There is nothing at this position in 1RXS, 2MASS, GCVS and AAVSO VSX.

This area of sky in Pegasus was observed by Palomar/NEAT project. 49 images were obtained on 15 nights from 1998 July 20 to 2005 Aug. 30. Object was in outburst on six images of 2001 Aug. 09 fading by Aug. 14 and at quiescence on 13 other nights, including 2001 Aug. 05.

Based on the amplitude of variability (~4m) and previous outburst we suggest that MASTER OT J215433.99+235400.8 is a cataclysmic variable, most likely a dwarf nova of UGSS (SS Cyg) type. Follow up observations are desirable. The discovery and reference images are available at: http://master.sai.msu.ru/static/OT/215433.99235400.8.png

List of Optical Transients discovered by MASTER

Global MASTER Robotic Net