Overlaid DSS image of IC 3993, 30' x 30' with north at top and west to the right
NPM1G +40.0305, PGC 3088024
|Size ||0.257' x 0.236' @ 15°|
|Right Ascension ||12h 59' 30.5" (2000)|
|Declination ||40° 36' 6" N|
|Constellation ||Canes Venatici|
IC 3993 is a galaxy at its catalogued position, found by Wolf on a Bruce 16-inch refractor plate, and confirmed on the print I examined. There is no problem with its identification.
However, the SDSS images from 25 April 2003 show a blue star superposed east of the nucleus by 5.1 arcseconds and 0.9 arcseconds north. The star does not appear on any of the other digitized surveys that I examined (DSS1, DSS2, or 2MASS), so may be a supernova (it is not included in the IAU supernova list, nor the possible supernova list, maintained at CfA). Fortunately, SDSS has it in all five bands, so the photometry and position are good if the object ever needs to be followed up.
See NGC 5521 for another possible supernova.
30 objects found within 60'
Drawings, descriptions, and CCD photos are copyright Andrew Cooper unless otherwise noted, no usage without permission.
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