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THE ASTRONOMER Electronic Circular No 2927      2013 Jly 02 13.10UT
Ed:Guy M Hurst, 16,Westminster Close, Kempshott Rise,  Basingstoke,
Hants, RG22 4PP,England.Telephone/FAX(01256)471074Int:+441256471074
INTERNET: GUY@TAHQ.DEMON.CO.UK      Backup: gmh@wdcc1.bnsc.rl.ac.uk
WORLD WIDE WEB                         http://www.theastronomer.org
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MASTER OT J174816.22+501723.3 - NEW CATACLYSMIC VARIABLE
Denis Denisenko, International Research School, Moscow, Russia reports on
The Astronomer's Telegram 5174 and corrected on 5182 that the MASTER-Amur
auto-detection system discovered an optical transient (OT) at 17h 48m 16.22s
DEC +50d 17m 23.3s (2000) on 2013 June 28.646UT. The OT unfiltered magnitude
is 15.6 (limit 18.4m). It is seen on four images. They have reference image
without the OT on 2013 May 13.694UT with unfiltered magnitude limit 18.2m. 

The object is identical to the blue star:
SDSS J174816.31+501723.3 (u=17.80 g=17.59 r=17.71 i=17.74 z=17.85). It is
present in the USNO-B catalogue as USNO-B1.0 1402-0303843 
(RA 17 48 16.316 DEC +50 17 23.28 (B1=16.69 R1=16.46 B2=18.02 R2=18.43
I=16.10).

The object was observed many times by Catalina Sky Survey, but was not
discovered as a transient. The light curve available shows at least five
outbursts, the brightest of them (15.5m) detected on 2009 Mar. 23. 

Based on the blue colour, amplitude of variability (about four magnitudes)
and previous outbursts we conclude that it is a new cataclysmic variable
(dwarf nova). The discovery and reference images are available at: 
http://master.sai.msu.ru/static/OT/174816.22501723.3.png 

THE ASTRONOMER MEETING, 2013 SEPTEMBER 28
Full details of the venue, speakers and a booking form have now been posted
to the TA home webpage at:
http://www.theastronomer.org/
Please use this booking form in preference to E2926 and complete and send to
the editor with your remittance. If you also require to take advantage of a
new trial subscription of the pdf magazine at the discounted rate please
send your form as soon as possible.

SUPERNOVA 2013ck (CATALINA SKY SURVEY)
2013ck  May 08.28   15 24 29.07  +48 32 54.6  17.5   1.1"W    1.8"N
L. Tomasella: spectrum May 9 type-Ia a few days before maximum.

SUPERNOVA 2013cl (CATALINA REAL-TIME TRANSIENT SURVEY)
2013cl  May 03.45   16 19 31.59  +24 47 11.3  17.9  27.4"E   18.2"S
L. Tomasella: Spectrum may 9 type-Ia about 10-12 days after maximum.

SUPERNOVA 2013cm (CATALINA SKY SURVEY)
2013cm  May 10.39   17 20 01.94  +23 44 51.3  18.3   7.7"E   10.3"S
C. McCully: spectrum May 11 with Keck II, subluminous type-Ia near maximum.

Guy M Hurst