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MASTER Discovery of Two New Cataclysmic Variables

ATel #6725; P. Balanutsa, S. Shurpakov, D. Denisenko, V. Lipunov, E. Gorbovskoy, N. Tiurina, V. Kornilov, N. Shatskiy, V. Chazov, A. Kuznetsov, V. Vladimirov, E. Popova (Lomonosov Moscow State University, SAI), A. Tlatov, D. Dormidontov, V. Senik, A. Parkhomenko (Kislovodsk Solar Station of Pulkovo Observatory), K. Ivanov, S. Yazev, N. Budnev, E. Konstantinov, O. Chuvalaev, V. Poleshchuk, O. Gress (Irkutsk State University), V. Krushinsky, I. Zalozhnih, A. Popov, A. Bourdanov (Ural Federal University), V. Yurkov, A. Gabovich, Y. Sergienko, E. Sinyakov (Blagoveshchensk Educational University), V. Shumkov (MASTER team member)
on 20 Nov 2014; 17:35 UT
Credential Certification: Nataly Tyurina (tiurina@sai.msu.ru)

Subjects: Optical, Cataclysmic Variable, Transient

MASTER OT J183255.21+242431.5 - new CV

MASTER-Kislovodsk auto-detection system discovered OT source at (RA, Dec) = 18h 32m 55.21s +24d 24m 31.5s on 2014-11-13.65598 UT. The OT unfiltered magnitude is 16.8m (limit 19.8m). The OT is seen in 8 images. There is no minor planet at this place. We have reference image without OT on 2012-08-19.74270 UT with unfiltered magnitude limit 19.5m.

The OT at quiescence is identical to the blue star USNO-B1.0 1144-0296490 (B1=20.86 B2=21.57 R2=19.54). The star is showing variability on the digitized Palomar plates. Color-combined DSS finder chart is uploaded to http://master.sai.msu.ru/static/OT/J183255+242431-BRIR5x5.jpg (2x zoom). The object has an UV counterpart GALEX J183255.2+242430 (NUV=21.25+/-0.17). Nothing is present at this position in 1RXS, 2MASS, GCVS and AAVSO VSX. This area of sky in Hercules is not covered by SDSS and Catalina Sky Survey. The object was at quiescence on three Palomar/NEAT images of 2003 Aug. 08.

Based on the blue color and amplitude of variability (about 4m), MASTER OT J183255.21+242431.5 is a new cataclysmic variable (dwarf nova). Follow up observations are encouraged. The discovery and reference images are available at: http://master.sai.msu.ru/static/OT/183255.21242431.5.png

MASTER OT J021401.78+414218.0 - new CV

MASTER-Tunka auto-detection system discovered OT source at (RA, Dec) = 02h 14m 01.78s +41d 42m 18.0s on 2014-11-15.76551 UT. The OT unfiltered magnitude is 18.6m (limit 19.6m). The OT is seen in 4 images. There is no minor planet at this place. We have reference image without OT on 2010-10-10.74528 UT with unfiltered magnitude limit 19.7m.

The OT position is within 1" of the star GSC 2.3.2 NBZ7031521 (jmag=18.18) that was in outburst on the 1989 Sep. 08 POSS-II blue plate and at quiescence on other Palomar plates. Color-combined DSS finder chart is uploaded to http://master.sai.msu.ru/static/OT/J021401+414218-BRIR5x5.jpg (2x zoom). Nothing is present at this position in 1RXS, GALEX, 2MASS, GCVS and AAVSO VSX. This area of sky in Andromeda is not covered by SDSS. Catalina Sky Survey has two past detections in Orphan Catalogue as bright as 18.3m on 2007 Dec. 18 and 2010 Feb. 16. NEAT project has 17 images on 5 different nights from 1998 Nov. 16 to 2002 Oct. 19. No additional outbursts were detected.

Based on the amplitude of variability and previous outbursts, MASTER OT J021401.78+414218.0 is a new cataclysmic variable (dwarf nova). Follow up observations are encouraged. The discovery and reference images are available at: http://master.sai.msu.ru/static/OT/021401.78414218.0.png

List of Optical Transients discovered by MASTER

Global MASTER Robotic Net