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THE ASTRONOMER Electronic Circular No 2110      2005 May 08 19.35UT
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             GMH at AST.STAR.RL.AC.UK
WORLD WIDE WEB                         http://www.theastronomer.org
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SDSS J124819.36+072049.4
R. Quimby, M. Sellers, P. Mondol, P. Hoeflich, J. C. Wheeler, University 
of Texas, and C. Gerardy, Imperial College report on Astronomical 
Telegram 481, the discovery of a dwarf nova of magnitude 16.7 in 
unfiltered CCD images taken on 2005 Apr 26.25UT and Apr 28.20 (about 
17.0 mag) using the 0.45m ROTSE-IIIb telescope at the McDonald 
Observatory.

The object is located at RA = 12h 48m 19.38s DEC +07 20' 48.8" and was 
not detected in ROTSE-IIIb data from Apr 20.20 UT (limiting mag about 
17.0). The object had been observed by the Sloan Digital Sky Survey in 
quiescence at r=21.50 mag.

A spectrum (420-890 nm) of the object obtained on Apr 29.13 with the 
9.2m Hobby-Eberly Telescope (+ Marcario Low-Resolution Spectrograph) by 
S. C. Odewahn and   M. Villarreal, shows doubly peaked H-alpha emission, 
along with absorption lines from H-beta, H-gamma, HeI 447.1 nm and 587.6 
nm, and NaI 589 nm. ROTSE-IIIb data shows the object faded to about 17.7 
magnitude on May 1.14 UT.

Guy M Hurst