[vsnet-alert 13090] Re: DR UMa outburst!

Brian Skiff bas at lowell.edu
Tue Apr 5 12:51:43 JST 2011


On Mon, 2011-04-04 at 20:37 -0600, Tom Krajci wrote:
> Initial unfiltered images from Astrokolkhoz (C11, 90 seconds) show an 
> object at J2000  13 59 05.77 +55 44 29.49 at approx unfiltered mag 17.
> 
> At the SIMBAD coords for DR UMa (13 59 05.4 +55 44 04) approx 25 arcsec 
> away...nothing is detectable with a single image (fainter than mag 18?)


     This links DR UMa with SDSS J135905.74+554429.3, whose
position is:  13 59 05.74 +55 44 29.4  (J2000).  The Sloan proper
motion is near zero.  The SDSS photometry is clearly for a very
blue object, which would seem to make the ID certain, and thus the
GCVS/VSX coordinates are in error.  No Sloan spectrum unfortunately.
SDSS r magnitude = 20.00, presumably at quiescence.
     Although the object is listed as a candidate quasar in various
papers, I see no redshift determination from a _spectrum_ in the 
VizieR listing, only inference from colors and photometric redshift,
which is obviously wrong.


\Brian


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