[vsnet-alert 16929] Three new MASTER CVs

[Taichi Kato]

Three new MASTER CVs

ATEL #5898

MASTER OT J054111.82+454054.9 - possible new CV

MASTER-Amur auto-detection system discovered OT source at (RA, Dec) = 
05h 41m 11.82s +45d 40m 54.9s on 2014-02-16.45971 UT. The OT 
unfiltered magnitude is 15.8m (limit 17.7m). The OT is seen in 2 
images. There is no minor planet at this place. We have reference 
image without OT on 2012-10-18.64654 UT with unfiltered magnitude 
limit 18.6m. 

The OT at quiescence is identical to the blue star USNO-B1.0 
1356-0161028 (05 41 11.816 +45 40 56.27 pmRA=2 pmDE=30 B1=19.44 
R2=20.16 I=18.38) = <a 
href="http://skyserver.sdss3.org/dr8/en/tools/explore/obj.asp?id=1237653742020986631">SDSS

J054111.84+454055.3</a> (u=20.54 g=20.50 r=20.23 i=19.74 z=19.51). 

There is nothing at this position in 1RXS, GALEX, 2MASS, GCVS and 
AAVSO VSX. Object was at minimum light on 6 DSS plates and on 4 NEAT 
images. This area of sky in Auriga is not covered by CRTS. 

Based on the blue color and amplitude of variability (~5m), MASTER OT 
J054111.82+454054.9 is 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/054111.82454054.9.png 

ATEL #5899

MASTER OT J163152.63+300645.1 - new CV

MASTER-Amur auto-detection system discovered OT source at (RA, Dec) = 
16h 31m 52.63s +30d 06m 45.1s on 2014-02-16.81234 UT. The OT 
unfiltered magnitude is 15.7m (limit 17.1m). The OT is seen in 4 
images. We have reference 
image without OT on 2012-09-05.48694 UT with unfiltered magnitude 
limit 18.7m. The object was observed in outbursts to 15.7m on 
MASTER-Amur single images of 2010-06-09.712 UT and 2012-12-19.900 UT, 
but was not detected as a transient then. 

The OT at quiescence is identical to the blue star USNO-B1.0 
1201-0247710 (16 31 52.665 +30 06 46.55 B1=20.37 B2=20.73) = <a 
href="http://skyserver.sdss3.org/dr8/en/tools/explore/obj.asp?id=1237662499473588338">SDSS

J163152.66+300646.1</a> (u=17.23 g=16.83 r=17.08 i=17.27 z=17.39). The

star was definitely in another outburst during SDSS observations. 
Color-combined (BRIR) finder chart is uploaded to 
http://master.sai.msu.ru/static/OT/J163152+300645-BRIR5x5.jpg (2x 
zoom). There is also an UV counterpart with two entries in GALEX DR6: 
<a href="http://galex.stsci.edu/GR6/?page=explore&photo=true&objid=6371443588717346922">GALE
X

J163152.7+300646</a> (FUV=21.22+/-0.40 NUV=20.74+/-0.22) and <a 
href="http://galex.stsci.edu/GR6/?page=explore&photo=true&objid=6371443598381028702">GALEX

J163152.6+300647</a> (FUV=20.78+/-0.28 NUV=20.49+/-0.11). 

There is nothing at this position in 1RXS, 2MASS, GCVS and AAVSO VSX. 
There is a faint X-ray source in Swift XRT point source catalogue 
1SXPS J163152.7+300643 with the flux 0.00099 (+0.00040/-0.00034) 
cnts/s. 

Catalina Sky Survey observed this area of sky in Hercules with 77 
positive detections from April 2005 to Sep. 2013.  Most of time the object
is varying between 
20-21m with one outburst to 16.3-16.4m on 2011 May 20. 

Based on the blue color and outburst amplitude (~5m), MASTER OT 
J163152.63+300645.1 is most 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/163152.63300645.1.png 

ATEL #5900

MASTER OT J065921.17+102943.0 - possible Cataclysmic Variable

MASTER-Amur auto-detection system discovered OT source at (RA, Dec) = 06h
59m 21.17s +10d 29m 43.0s on 2014-02-18.50572 UT. The OT unfiltered magnitude
is 15.6m (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 2012-09-24.83476 UT
with unfiltered magnitude limit 18.3m. 

The OT at quiescence is identical to the blue star USNO-B1.0 1004-0122737
(06 59 21.152 +10 29 43.43 pmRA=8 pmDE=-8 B1=19.35 R1=N/A B2=19.40 R2=17.19
I=18.75). Color-combined (BRIR) finder chart is uploaded to http://master.sai.msu.ru/static/
OT/J065921+102943-BRIR5x5.jpg
(2x zoom). The object is showing the large variability between 1st and
2nd epoch Palomar plates. Comparison of POSS-I and POSS-II red plates is
posted at http://master.sai.msu.ru/static/OT/J065921+102943-POSS-Red.jpg

There is nothing at this position in 1RXS, 2MASS, GCVS and AAVSO VSX. This
area of sky in Monoceros is not covered by GALEX, SDSS and CRTS. 

Based on the proper motion and amplitude of variability, MASTER OT J065921.17+102943.0
is most likely a cataclysmic variable. Follow up observations are required.
The discovery and reference images are available at: http://master.sai.msu.ru/static/OT/0659
21.17102943.0.png