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OT and New Bright CV detected by MASTER

ATel #5905; V. Yecheistov, D. Denisenko, V. Lipunov, E. Gorbovskoy, P. Balanutsa, N. Tiurina, V. Kornilov, N. Shatskiy, V. Chazov, A. Kuznetsov, A. Rufanov, V. Vladimirov (Moscow State University, SAI), 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), 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, F. Podest (OAFA)
on 19 Feb 2014; 16:02 UT
Credential Certification: Nataly Tyurina (tiurina@sai.msu.ru)

Subjects: Optical, Cataclysmic Variable, Transient

MASTER OT J071247.50+095647.1 - CV or QSO

MASTER-Amur auto-detection system discovered OT source at (RA, Dec) = 07h 12m 47.50s +09d 56m 47.1s on 2014-02-18.50457 UT. The OT unfiltered magnitude is 16.5m (limit 17.5m). The OT is seen in 2 images. There is no minor planet at this place. We have reference image without OT on 2012-10-19.78471 UT with unfiltered magnitude limit 18.2m.

The OT at quiescence is identical to the blue star USNO-A2.0 0975-04801241 (07 12 47.44 +09 56 47.3 B=18.5 R=19.2) = USNO-B1.0 0999-0139661 (07 12 47.425 +09 56 47.26 pmRA=0 pmDE=0 B1=19.14 R1=19.19 B2=20.46 R2=N/A I=N/A). Color-combined DSS finder chart is uploaded to http://master.sai.msu.ru/static/OT/J071247+095647-BRIR5x5.jpg (2x zoom).

The object has an UV counterpart GALEX J071247.4+095647 (FUV=21.32+/-0.30 NUV=21.99+/-0.40). There is nothing at this position in 1RXS, 2MASS, GCVS and AAVSO VSX. This area of sky in Canis Minor is not covered by SDSS and CRTS.

MASTER OT J071247.50+095647.1 is likely a new cataclysmic variable (dwarf nova in outburst). Follow up observations are required. The discovery and reference images are available at: http://master.sai.msu.ru/static/OT/071247.50095647.1.png

MASTER OT J055845.55+391533.4 - bright CV

MASTER-Amur auto-detection system discovered OT source at (RA, Dec) = 05h 58m 45.55s +39d 15m 33.4s on 2014-02-19.47672 UT. The OT unfiltered magnitude is 14.4m (limit 18.2m). The OT is seen in 10 images. There is no minor planet at this place. We have reference image without OT on 2013-12-28.66015 UT with unfiltered magnitude limit 18.2m.

Checking MASTER-Tunka database we have found that the outburst had started at least 6 days ago, on 2014 Feb. 13, with the following unfiltered magnitudes: 2014-02-13.579 UT, 13.9m; 2014-02-13.625 UT, 13.9m. There were two previous outbursts in MASTER-Amur data: on 2011-11-28.517 UT to 14.6V and on 2012-11-19.574 UT to 14.0m (unfiltered).

The OT at quiescence is identical to the blue star USNO-B1.0 1292-0151637 (05 58 45.481 +39 15 32.61 pmRA=0 pmDE=0 B1=17.33 R1=18.47 B2=13.79 R2=17.43 I=17.30). Color-combined DSS finder chart is uploaded to http://master.sai.msu.ru/static/OT/J055845+391533-BRIR5x5.jpg (2x zoom). The object was in outburst on the 2nd epoch Palomar Blue plate of 1990-01-25, hence the blue color. Comparison of POSS-I and POSS-II blue plates is posted at http://master.sai.msu.ru/static/OT/J055845+391533-POSS-B.jpg

The object has an UV counterpart with two entries in GALEX data: GALEX J055845.5+391533 (NUV=19.02+/-0.09) and GALEX J055845.6+391534 (NUV=19.09+/-0.11). There is nothing at this position in 1RXS, 2MASS, GCVS and AAVSO VSX. This area of sky in Auriga is not covered by SDSS and CRTS. No previous outbursts were detected by NEAT on 12 images from 4 nights in Dec. 2001 - Feb. 2002.

Based on the amplitude of variability, previous detections and fading rate since Feb. 13th (~0.1m/day), MASTER OT J055845.55+391533.4 is a new cataclysmic variable, most likely a dwarf nova of UGSU (SU UMa) type in superoutburst. Follow up observations are required. The discovery and reference images are available at: http://master.sai.msu.ru/static/OT/055845.55391533.4.png

List of Optical Transients discovered by MASTER

Global MASTER Robotic Net