[Aavso-photometry] CI Cyg Comparison stars

[françois teyssier]

Hello!

Doing time serie photometry on CI Cyg, I've got a problem with the 
magnitude of reference star Label 88 (000-BCJ-157), 8.831 according to 
Henden, which gives me only approximative mesures for check stars 115 
and 117, with a 0.2 mag difference.

I've found that both Brian A. Skiff and Skopal use a different magnitude 
mesure  for star 88, about 0.2 mag brigther

IAUD 	Label 	Name 	V Henden 	V Skiff 	V Skopal
000-BCJ-157 	88 	HD 226041 	8.831 	8.588 	8.60
000-BCJ-223 	108 	GSC 2677-1273 	10.837 	10.673 	
000-BCJ-202 	115 	GSC 2861-0298 	11.548 	11.56 	
000-BCJ-186 	117 	GSC 2861-1332 	11.715 	11.722 	
000-BCJ-177 	125 	J195019+3539.5 	12.535 	12.52 	
000-BCJ-181 	135 	J195022+3541.1 	13.456 	13.42 	


Using 8.588 for star 88 (Skiff) gives me quiet good results for the 
check stars 115 and 117 (resp.  11.55 and 11.71). Note that for fainter 
stars, Henden and Skiff mesures are in good agreement.

Have other observers the same issue or perhaps I'm wrong?

Thank you for your answer
Best regards

François Teyssier (France)


References :
Skiff B.A., IBVS, 4892, 2000
Skopal, Contributions of the Astronomical Observatory Skalnaté Pleso, 
vol. 34, no. 1, p. 45-69, 2004