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Flare Star and two new CVs discovered by MASTER

ATel #5632; D. Denisenko, S. Shurpakov, V. Lipunov, E. Gorbovskoy, N. Tiurina, P. Balanutsa, V. Kornilov, A. Belinski, N. Shatskiy, V. Chazov, A. Kuznetsov, A. Rufanov, 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), A. Parkhomenko, A. Tlatov, D. Dormidontov, V. Senik (Kislovodsk Solar Station of Pulkovo Observatory), V. Yurkov, Y. Sergienko, D. Varda, E. Sinyakov, A. Gabovich (Blagoveshchensk Educational University), V. Krushinsky, I. Zalozhnih, A. Popov, A. Bourdanov (Ural Federal University), P. Podvorotny, V. Shumkov (MASTER team members), H. Levato, C. Saffe (ICATE), C. Mallamaci, C. Lopez, F. Podest (OAFA)
on 6 Dec 2013; 12:24 UT
Credential Certification: Vladimir Lipunov (lipunov2007@gmail.com)

Subjects: Optical, Cataclysmic Variable, Transient, Variables

MASTER OT J003133.10+113635.4 - new flare star

MASTER-Tunka auto-detection system discovered OT source at (RA, Dec) = 00h 31m 33.10s +11d 36m 35.4s on 2013-12-03.47017 UT. The OT unfiltered magnitude is 15.3m (limit 19.3m). The OT is seen in 9 images. There is no minor planet at this place. We have reference image without OT on 2011-12-16.54503 UT with the OT at unfiltered magnitude 18.7m (limit 19.7m). The object was not present on unfiltered images obtained 45 minutes earlier, on 2013 Dec. 03.437-03.440 UT to m_lim=18.5.

The OT at quiescence is identical to the red star USNO-B1.0 1016-0004712 (00 31 33.199 +11 36 36.25 pmRA=-50 pmDE=-34 R1=19.81 B2=20.25 R2=19.76 I=17.02) = SDSS J003133.16+113635.7 (u=24.89 g=22.53 r=20.70 i=17.98 z=16.51) = 2MASS 00313320+1136359 (J=14.59+/-0.03 H=13.89+/-0.05 K=13.53+/-0.05).

There is nothing at this position in 1RXS, GCVS and AAVSO VSX. No flares were detected by CRTS. Based on the color, amplitude (~4m) and short rise time, MASTER OT J003133.10+113635.4 is the new variable of UV Ceti type (flaring red dwarf). Follow up observations are desirable. The discovery and reference images are available at: http://master.sai.msu.ru/static/OT/003133.10113635.4.jpg

MASTER OT J033619.97+445318.5 - new CV

MASTER-Kislovodsk auto-detection system discovered OT source at (RA, Dec) = 03h 36m 19.97s +44d 53m 18.5s on 2013-12-05.76405 UT. The OT unfiltered magnitude is 17.4m (limit 19.0m). The OT is seen in 8 images. We have reference image without OT on 2011-10-27.98278 UT with unfiltered m_lim=20.1.

The OT is identical to the blue star USNO-A2.0 1275-02473814 (03 36 19.98 +44 53 17.9 R=18.3 B=18.3). It was detected in outburst on 1953 Jan. 10 POSS plates and by Sloan Sky Survey as SDSS J033619.99+445317.8 (u=18.88 g=18.15 r=17.98 i=17.95 z=17.93). The star is about B=21.5 on 2nd epoch Palomar plates. Comparison of 1953, 1989 and 1993 Blue Palomar plates is uploaded to http://master.sai.msu.ru/static/OT/J033619+445318-POSS-B.jpg (6'x6' FOV).

There is nothing at this position in 1RXS, 2MASS, USNO-B1.0, GCVS and AAVSO VSX. This area of sky in Perseus is not covered by NEAT and CRTS.

Based on the blue color and previous outbursts, MASTER OT J033619.97+445318.5 is most likely a dwarf nova of UGSS or USGU type. Follow up observations are required. The discovery and reference images are available at: http://master.sai.msu.ru/static/OT/033619.97445318.5.png

We also note the new variable star located 3.7' south-west of MASTER OT J033619.97+445318.5. It is marked on the chart as Var. The star is bright on eight DSS plates but faded by ~3m on 1993-01-23 Blue plate. It is present in catalogs as USNO-B1.0 1348-0080021 (03 36 03.976 +44 50 50.08 B1=17.09 R1=15.96 B2=20.05 R2=16.03 I=15.49), SDSS J033603.97+445049.6 (u=19.74 g=18.01 r=17.08 i=16.68 z=16.39) and 2MASS 03360396+4450497 (J=14.73+/-0.04 H=14.28+/-0.05 K=14.10+/-0.06). 2MASS colors suggest the early K spectral class. The star appears to be a deeply eclipsing variable and deserves additional observations.

MASTER OT J060608.52+470042.3 - new CV

MASTER-Tunka auto-detection system discovered OT source at (RA, Dec) = 06h 06m 08.52s +47d 00m 42.3s on 2013-12-05.64583 UT. The OT unfiltered magnitude is 16.3m (limit 18.9m). The OT is seen in 3 images. We have reference image without OT on 2012-10-17.91027 UT with magnitude limit in V filter 19.2m.

There is nothing at this position in any catalogs. This area of sky in Auriga is not covered by SDSS, NEAT and CRTS. Based on the outburst amplitude (~5m), MASTER OT J060608.52+470042.3 is likely a dwarf nova 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/060608.52470042.3.png

List of Optical Transients discovered by MASTER

Global MASTER Robotic Net