[vsnet-chat 3538] Re: FBS 2351+228 = NSV 26158 outburst length...

[no name <crawl@zoom.co.uk>]

Brian Skiff wrote:
> 
>      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.

Therefore FBS2351+228 is _not_ in outburst on any of the survey plates.

Armed with good ol' hindsight, I've just re-examined the 2MASS images of
this star and the nearby GSC 2252 02143 in the near-infrared bands of J,
H and Ks, and as in the IV-N plates, these two stars appear of equal
brightness in these passbands.

With a little bit more foresight, I should have noticed this at first...

...sorry if I've confused anybody!

>      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.

Is this is proper motion a bit sizeable for a red giant [vis the
symbiotic idea] given  the [v.roughly] about 1" declination travel per
near two decades, especially considering the apparent magnitude?

I'm also a bit muddled as by the FBS notation : how do we tell if it is
from the FBS spectral survey for blue objects, or the one for late
objects? If we've a red star found in a blue object survey, okay,
symbiotic, but if a red object found in a late type star survey, not
much in the surprise line.

John

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