Two new CVs detected by MASTER

ATel #5451; P. Balanutsa, D. Denisenko, E. Gorbovskoy, V. Lipunov, N. Tiurina, V. Kornilov, A. Belinski, N. Shatskiy, V. Chazov, A. Kuznetsov, V. Yecheistov, V. Vladimirov (Moscow State University, SAI), K. Ivanov, S. Yazev, N. Budnev, E. Konstantinov, O. Chuvalaev, V. Poleshchuk, O. Gress, A. Frolova (Irkutsk State University), 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), 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 and F. Podest (OAFA)
on 7 Oct 2013; 17:39 UT
Credential Certification: Vladimir Lipunov (lipunov2007@gmail.com)

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MASTER OT J063100.30+260253.3 - new bright CV

MASTER-Tunka auto-detection system discovered OT source at (RA, Dec) = 06h 31m 00.30s +26d 02m 53.3s on 2013-10-03.91347 UT. The OT unfiltered magnitude is 14.9m (limit 18.7m). The OT is seen in 12 images. There is no minor planet at this place. We have reference image with OT at 18.0m on 2011-12-24.72708 UT (m_lim=19.7). The object was also bright (15.8m) on three images obtained on 2012 Mar. 11.585-11.590 UT.

Object is showing the variability between the 1st and 2nd Palomar epochs. Comparison of POSS-I and POSS-II Red plates obtained in 1949 and 1990 is uploaded to http://master.sai.msu.ru/static/OT/J063100+260253-POSS-R.jpg (5'x5' FOV). The star is present in various catalogs as USNO-A2.0 1125-04091236 (06 31 00.32 +26 02 52.8 R=15.5 B=14.4), USNO-B1.0 1160-0116839 (06 31 00.279 +26 02 53.11 pmRA=-6 pmDE=4 B1=14.95 R1=15.32 B2=16.89 R2=17.72 I=17.48), 2MASS J06310028+2602529 (J=14.58+/-0.03, H=14.36+/-0.04, K=14.13+/-0.04) and SDSS J063100.28+260252.8 (u=18.73 g=18.18 r=17.68 i=17.33 z=17.05). There is also an UV counterpart GALEX J063100.3+260252 (FUV=20.75+/-0.15, NUV=20.60+/-0.11). There is nothing at this position in 1RXS, GCVS and AAVSO VSX. This area of sky in Gemini is not covered by CRTS.

Based on the blue color and amplitude of variability we conclude that MASTER OT J063100.30+260253.3 is a new cataclysmic variable, probably a dwarf nova. Follow up observations are required. The discovery and reference images are available at: http://master.sai.msu.ru/static/OT/063100.30260253.3.png

MASTER OT J022906.32+275222.3 - new CV

MASTER-Tunka auto-detection system discovered OT source at (RA, Dec) = 02h 29m 06.32s +27d 52m 22.3s on 2013-10-05.77687 UT. The OT unfiltered magnitude is 17.9m (limit 19.9m). The OT is seen in 10 images. There is no minor planet at this place. We have reference image without OT on 2011-10-05.74106 UT with unfiltered magnitude limit 19.9m.

There is a faint blue star at this position on Palomar plates present in USNO-B catalogue as USNO-B1.0 1178-0050655 (02 29 06.299 +27 52 21.81 B1=20.42 B2=20.94). Color-combined DSS finder chart is uploaded to http://master.sai.msu.ru/static/OT/J022906+275222-BRIR.jpg (10'x10' FOV). There is an UV counterpart GALEX J022906.3+275222 with FUV=23.50+/-0.29, NUV=22.44+/-0.16 (object falls into deep images of UGC 1922 field with 75-min exposures). Nothing is present at this position in 1RXS, 2MASS, GCVS and AAVSO VSX. This area of sky in Triangulum is not covered by SDSS. Object is definitely varying from ~20.5m to 17.5m in Catalina Sky Survey data.

Based on the blue color and amplitude of variability we suggest that MASTER OT J022906.32+275222.3 is likely a new cataclysmic variable. Follow up observations are required. The discovery and reference images are available at: http://master.sai.msu.ru/static/OT/022906.32275222.3.png

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