[vsnet-chat 187] Re V3941 Sgr

[Mati Morel <morel@ozemail.com.au>]

Dear vs-chatters,
Regarding the position of V3941 Sgr, I should put in my 2 cents worth
as I prepared the VSS, RASNZ charts in the first place.
The first finder chart appeared in Journal of AAVSO 2,2, 63 (1973) by
Barbara Capon. The star was observed to undergo three sharp outbursts in 
80-day interval centred on JD 2441140, and apparently quiescent outside
that time frame. Anyway, she provided a small finder chart, which I 
consider identifies the variable unambiguously. Her identification
has been repeated, if not confirmed, in the Downes and Shara atlas of
dwarf novae. And of course it is repeated on VSS chart 1116.

My problem, in 1994, when drawing the surrounding star field, was that
I had no adequate V-band image of the field to faint magnitudes. The
GSC did not seem to go faint enough. [I had no Internet connection at
that time, so could not access DSS.]  So I used the IR charts published
by S.W. McCuskey and R. Mehlhorn, Astron. J. 68,5,319 (1963).
V3941 Sgr lies in Field 8.  V3941 Sgr is identifiable on their chart 2(h)
just below star 72, and just to the right of 69.  There is no suggestion
that V3941 Sgr is a red giant, as the rest of the field is populated
with dozens of identified late-M giants. Kato's variable star "B" does
not match any of the marked M-giants either.

In conclusion, the identification of V3941 Sgr seems correct. I tend to
think this variable spends much time in quiescence, until ....

VSS chart 1116, being based on an _IR_ image, is bound to contain 
anomalous star dots - some understated, some overstated, and perhaps one
or two which ought not to be there at all. My apologies for any difficulties
this may cause. 

Regards,
Mati

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