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Special Notice #321: Observations critical tonight for SDSS J093249.57+472523.0

January 10, 2013: Further to AAVSO Alert Notice 471 ( and AAVSO Special Notice #319 (, tonight's observations of SDSS J093249.57+472523.0 will be critical, as sometime tomorrow (January 11) the scheduling team will make the final decison about going ahead with the HST COS observations planned for

                                           2013 January 11 21:18:00 through January 12 02:57:19 UT

PI Dr. Boris Gaensicke requests that if at all possible, please try to get some V-band images of this target tonight. Assuming the satellite observations go ahead January 11-12, please give this object high priority throughout the observing window, as instructed below.

Coordinates for SDSS J093249.57+472523.0:  R.A. 09 32 49.58   Dec. +47 25 23.2   (2000.0)

As instructed in AAVSO Alert Notice 471, for CCD observers, simultaneous photometry [shortly before, during, and after the HST observations] would be ideal. B filter would be best for a light curve, although for the magnitude estimates, a V measurement would be best. An uninterrupted light curve would be better than cycling between filters. At 17.9V at minimum (unknown at maximum), SDSS J093249.57+472523.0 is most likely too faint for positive visual observations at minimum. If positive visual observations are possible, however, they are welcome, as are visual fainter-than observations fainter than magnitude 15.0.

Charts may be created using VSP (

Please report observations as soon as possible to the AAVSO International Database as SDSS J093249.57+472523.0. If an outburst is detected, please report observations immediately. Many thanks!

This AAVSO Special Notice was compiled by Elizabeth O. Waagen.


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