Possible Supernova and new CV discovered by MASTER

ATel #6003; S. Shurpakov, V. Shumkov, D. Denisenko, V. Lipunov, E. Gorbovskoy, N. Tiurina, P. Balanutsa, V. Kornilov, N. Shatskiy, V. Chazov, A. Kuznetsov, V. Vladimirov, V. Yecheistov (Moscow State University, SAI), K. Ivanov, S. Yazev, N. Budnev, E. Konstantinov, O. Chuvalaev, V. Poleshchuk, O. Gress (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 (MASTER team member), H. Levato, C. Saffe (ICATE), C. Mallamaci, C. Lopez, F. Podest (OAFA)
on 23 Mar 2014; 10:43 UT
Credential Certification: Nataly Tyurina (tiurina@sai.msu.ru)

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MASTER OT J124655.20+410205.3 - possible Supernova

MASTER-Tunka auto-detection system discovered OT source at (RA, Dec) = 12h 46m 55.20s +41d 02m 05.3s on 2014-03-22.80884 UT. The OT unfiltered magnitude is 17.8m (limit 19.1m). The OT is seen in 6 images. There is no minor planet at this place. We have reference image without OT on 2011-04-26.68962 UT with unfiltered magnitude limit 20.8m. Sum of six 60-sec unfiltered exposures by MASTER-Tunka on 2014 Mar. 22.762-22.809 UT is uploaded to http://master.sai.msu.ru/static/OT/J124655+410205-MASTER-Tunka.jpg

The new object is located 1" east and 1" south of the center of galaxy SDSS J124655.13+410206.1 (g=19.59 r=19.34 i=19.17). Spectral confirmation is required. Discovery and reference images are available at: http://master.sai.msu.ru/static/OT/124655.20410205.3.png

MASTER OT J184426.78+365140.7 - new CV

MASTER-Tunka auto-detection system discovered OT source at (RA, Dec) = 18h 44m 26.78s +36d 51m 40.7s on 2014-03-22.83331 UT. The OT unfiltered magnitude is 16.4m (limit 17.4m). The OT is seen in 2 images. There is no minor planet at this place. We have reference image without OT on 2012-06-25.76895 UT with unfiltered magnitude limit 18.8m. There was another outburst in the archival MASTER-Tunka images on 2011-07-01.717 UT to 17.2m.

There is a faint star (~21.5m) near the position of the OT on blue Palomar plates. Color-combined (BRIR) finder chart is uploaded to http://master.sai.msu.ru/static/OT/J184426+365140-BRIR5x5.jpg (2x zoom). The star shows a proper motion between the 1st and 2nd epoch POSS plates. The animation of OVR (1950) and BRIR (1991-1994) images is uploaded to http://master.sai.msu.ru/static/OT/J184426+365140-DSS-anim.gif (4'x4' FOV). We also note the nearby star 9" west and 7" south of the OT (with the position measured from digitized POSS-II plates 18 44 25.98 +36 51 33.3) showing a common proper motion with the variable.

There is nothing at the position of the OT in 1RXS, 2MASS, USNO, GCVS and AAVSO VSX. Object was at minimum light on 6 NEAT images of 1998 July 19-20. This area of sky in Lyra is not covered by GALEX, SDSS and CRTS.

Based on the amplitude of variability (~5m), proper motion and previous detection, MASTER OT J184426.78+365140.7 is a new cataclysmic variable, most likely a dwarf nova of SU UMa (UGSU) type in superoutburst. Follow up observations are encouraged. The discovery and reference images are available at: http://master.sai.msu.ru/static/OT/184426.78365140.7.png

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