[vsnet-chat 3537] Re: FBS 2351+228 = NSV 26158 outburst length...

[Brian Skiff <bas@lowell.edu>]

     The IV-N plates are indeed quite different from ordinary red plates,
since they record light longward of ~8000A, i.e. they are "infrared" plates,
but probably best nowadays called "far red".  The best comparison to make
is the POSS-I E plate with the POSS-II IIIa-F plates, or POSS-I O with the
POSS-II IIIa-J plates.  Actually it is very useful to have four POSS-II
plates in all three colors.  
     Note that differenece in the A2.0 and GSC positions is almost certainly
due to proper motion in the intervening 30 years:

23 53 51.07  +23 09 20.4   (POSS-I, epoch 1953.61)
23 53 50.96  +23 09 19.3   (GSC-ACT, epoch 1983.78)

...since the difference is way larger than the real external errors on the
two catalogues.  The 2MASS position will provide a third epoch and should be
usable with the other two to get a fairly good proper motion.  The star is 
not in AC2000.
     The GSC magnitude, 14.8 (slightly redward of V), is completely 
consistent with the USNO-A2.0 red magnitude, so there's no evidence of
outburst on POSS-I, POSS-II (comparing all the J and F exposures), or in
the GSC image.

\Brian

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