[vsnet-alert 5210] Re: V550 Cyg position

[Hitoshi YAMAOKA <yamaoka@rc.kyushu-u.ac.jp>]

Re: V550 Cyg position

>    By comparing the images (in outburst) and available charts, the
>real position of V550 Cyg seems to be slightly east to the DWS
>position. 
>More accurate astrometry pending Yamaoka-san's analysis.

I have measured with the Ouda image as:

20h05m05s.21, 32o21'21".0  (GSC-ACT 22 stars)
      05s.20,       21".6  (USNO-A2.0 24 stars)

Thus, the object observed by O'conner (vsnet-obs 29250) is not the
real V550 Cyg, and the position mentioned on vsnet-campaign 435
(weekly Campaign Summary by Uemura) is incorrect.

And, the DWS position (20h05m05s.0, +32o21'23") and the position of
the candidate of V550 Cyg at quiesient (Skiff, 1999, IBVS 4675,
20h05m04s.9, +32o21'24" = USNO-A2.0 1200_14392081) slightly differ
from our measurement: the real V550 Cyg is about 3" east or
east-southeast from these position.  

Further, on the DSS2 Bj images, the faint object lies on the neighbour
of the position I measured: the magnitude is about 19.5-20.0,
comparing with USNO_A2.0 bmags.  I could not find it on R images of
both DSS1 and 2.

Conclusively, USNO-A2.0 1200_14392081 seems not to be the quiesient
state of V550 Cyg; the amplitude of this CV is quite large, likely
more than 5 magnitude.

Sincerely Yours,
Hitoshi Yamaoka, Taichi Kato, and Hidetoshi Iwamatsu
VSNET Collaboration team

VSNET Home Page

Return to Daisaku Nogami

---

vsnet-adm@kusastro.kyoto-u.ac.jp