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Bright CV and four Red variables detected by MASTER

ATel #4956; P. Balanutsa, S. Shurpakov, V. Shumkov, P. Podvorotny, D. Denisenko, V. Lipunov, E. Gorbovskoy, N. Tiurina, V. Kornilov, A. Belinski, N. Shatskiy, V. Chazov, A. Kuznetsov, V. Yecheistov, 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, A. Frolova, (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) (MASTER team members), H. Levato, C. Saffe (ICATE), C. Mallamaci, C. Lopez and F. Podest (OAFA)
on 5 Apr 2013; 23:33 UT
Credential Certification: Vladimir Lipunov (lipunov2007@gmail.com)

Subjects: Optical, Cataclysmic Variable, Transient, Variables

MASTER OT J111759.87+765131.6 - new bright CV

MASTER-Amur auto-detection system discovered OT source at (RA, Dec) = 11h 17m 59.87s +76d 51m 31.6s on 2013-04-04.70913 UT. The OT unfiltered magnitude is 14.5m (limit 19.1m). The OT is seen in 2 images. There is no minor planet at this place. We have reference image without OT on 2013-02-15.62226 UT with unfiltered magnitude limit 19.0m.

The new object is identical to the blue star SDSS J111759.71+765130.5 (u=21.32 g=21.18 r=21.19 i=21.04 z=20.63). It shows variability on blue DSS plates and is present in USNO-B catalog as USNO-B1.0 1668-0059833 (11 17 59.451 +76 51 31.11 B1=20.74 B2=20.84) and in GSC 2.3.2 with jmag=21.24. No previous outbursts were detected on 12 Palomar plates. Nothing is present at this position in 1RXS, 2MASS, GCVS and AAVSO VSX. This area of sky is not covered by CSS.

Based on the blue color and amplitude of variability we conclude that MASTER OT J111759.87+765131.6 is a new cataclysmic variable, most likely the dwarf nova of UGSU (SU UMa) subtype in superoutburst. Follow up observations are encouraged. The discovery and reference images are available at: http://master.sai.msu.ru/static/OT/111759.87765131.6.png

MASTER-Amur has also detected four previously unknown large-amplitude red variables during an excursion to the populated Milky Way regions usually avoided in the course of survey. Some details for the new objects are listed in the table below. Magnitudes and upper limits are unfiltered with the red (USNO-B1.0) zero point.

MASTER OTObs. date, UTMag.Ref. date, UTLimit2MASS IDJHK
J195120.80+294749.52013-04-03.68813.32012-04-17.64815.119512079+29474968.887.416.58
J192518.38+214039.52013-04-03.73614.12012-04-17.64315.619251834+21403788.176.846.03
J201633.83+360629.42013-04-04.80716.12012-04-17.70017.220163376+360626210.188.267.58
J191235.75+111010.22013-04-05.73215.32012-07-23.61417.619123571+11101139.257.526.54

Notes.

Click on the object name to see the discovery and reference images.

MASTER OT J195120.80+294749.5 DSS finder chart.

MASTER OT J192518.38+214039.5 = IRAS 19231+2134. The object is showing variability on infrared DSS plates.

MASTER OT J201633.83+360629.4 is showing variability on infrared DSS plates.

MASTER OT J191235.75+111010.2 = IRAS 19102+1104. The object is showing variability on infrared DSS plates.

List of Optical Transients discovered by MASTER

Global MASTER Robotic Net