Two bright OTs detected by MASTER

ATel #4682; P. Balanutsa, V. Yecheistov, D. Denisenko, V. Lipunov, E. Gorbovskoy, N. Tiurina, V. Kornilov, A. Belinski, N. Shatskiy, V. Chazov, A. Kuznetsov, D. Zimnukhov (Moscow State University, SAI), V. Krushinsky, I. Zalozhnih, A. Popov, A. Bourdanov, A. Punanova (Ural Federal University), K. Ivanov, S. Yazev, N. Budnev, E. Konstantinov, O. Chuvalaev, V. Poleshchuk, O. Gress (Irkutsk State University), A. Parkhomenko, A. Tlatov, D. Dormidontov, V. Senik (Kislovodsk solar station of the Pulkovo observatory RAS), V. Yurkov, Y. Sergienko, D. Varda, E. Sinyakov (Blagoveshchensk Educational University), V. Shumkov, S. Shurpakov, P. Podvorotny (MASTER team members), H. Levato, C. Saffe (ICATE), C. Mallamaci, C. Lopez and F. Podest (Observatorio Astronomico Felix Aguilar; OAFA)
on 27 Dec 2012; 16:02 UT
Credential Certification: Vladimir Lipunov (lipunov2007@gmail.com)

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MASTER OT J030128.77+401104.9 - new bright CV

MASTER-Amur auto-detection system discovered OT source at (RA, Dec) = 03h 01m 28.77s +40d 11m 04.9s on 2012-12-27.47380 UT. The OT unfiltered magnitude is 15.1m (limit 17.9m). The OT is seen in 2 images. There is no minor planet at this place. We have reference image without OT on 2011-09-06.79588 UT with magnitude limit in 'V' filter 19.2m.

Nothing is present at this position in USNO-B1.0, GSC 2.3.2, 2MASS, 1RXS, GCVS and in AAVSO VSX. There is a faint star (~21m) within 1" of the OT on digitized POSS plates. Color-combined (BRIR) finder chart is posted at http://master.sai.msu.ru/static/OT/J030128+401104-BRIR5x5.jpg

This area of sky is not covered by SDSS and GALEX. No previous outbursts were detected on 6 Palomar/NEAT images obtained on 1997 Nov. 30 and 2002 Nov. 15, as well as on Catalina Sky Survey images.

Based on the amplitude of variability (about 6m) we conclude that MASTER OT J030128.77+401104.9 is a new cataclysmic variable in outburst. Follow up observations are required.

The discovery and reference images are available at: http://master.sai.msu.ru/static/OT/030128.77401104.9.png

MASTER OT J105025.99+332811.4 - dwarf nova

MASTER-Amur auto-detection system discovered OT source at (RA, Dec) = 10h 50m 25.99s +33d 28m 11.4s on 2012-12-25.72405 UT. The OT unfiltered magnitude is 16.4m (limit 17.8m). The OT is seen in 2 images. There is no minor planet at this place. We have reference image without OT on 2012-10-19.85023 UT with unfiltered magnitude limit 18.5m.

The OT was also detected by MASTER-Kislovodsk on 3 images (60-sec exposures) taken on Dec. 21. The following unfiltered magnitudes were measured:

2012-12-19.677 16.3 MASTER-Amur
2012-12-19.709 16.3 MASTER-Amur
2012-12-21.013 16.4 MASTER-Kislovodsk
2012-12-21.014 16.5 MASTER-Kislovodsk
2012-12-21.015 16.0 MASTER-Kislovodsk
2012-12-25.693 16.4 MASTER-Amur
2012-12-25.724 16.4 MASTER-Amur

This OT is identical to the blue star SDSS J105025.99+332812.9 (u=22.74 g=22.53 r=22.29 i=22.56 z=22.63). Nothing is present at this position in USNO-B1.0, GSC 2.3.2, 2MASS, 1RXS and GCVS catalogs, as well as in AAVSO VSX. No previous outbursts were detected by CRTS and Palomar/NEAT.

Based on the amplitude of variability (about 6m) and blue color at quiescence we conclude that MASTER OT J105025.99+332811.4 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/105025.99332811.4.png

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