Return to Home Page
I had a few hours back in Flagstaff to read email and take care
of a few matters before my next trip. I did the astrometry/photometry
on the TK4 quiescent images that were taken with the
1.0m on 011018UT (HJD 2455200.616). The
results are as follows, for the close north/south pair:
RA (J2000) DEC V B-V verr bverr
North 19:13:58.40 +40:44:12.3 20.84 1.56 0.057 0.179
South 19:13:58.42 +40:44:09.2 21.26 0.18 0.102 0.125
The astrometric error is about 100mas. Obviously, the
southern star both matches the position given in IBVS 5058
(19:13:58.47 +40:44:09.1 J2000) and is a blue star.
Beware of the northern companion as it will appear a couple of
magnitudes brighter for those observing unfiltered. I think the
USNO-A position of the northern red companion has been compromised
by the light from TK4 and so is unreliable; there is no evidence
of proper motion for either star.
I have also placed a revised finding chart on the ftp server:
http://ftp.nofs.navy.mil/pub/outgoing/aah/temp/tk4v.jpg
(this is a 3.4x3.4 arcmin field, Vband, pretty deep)
Note that both a single-night field photometry file and
Bruce Sumner's sequence for this field also reside there:
http://ftp.nofs.navy.mil/pub/outgoing/aah/sequence/tk4.dat
http://ftp.nofs.navy.mil/pub/outgoing/aah/sequence/sumner/tk4.seq
As to whether an outburst was seen, the observers will have to
tell us which star(s) they were actually observing.
Arne
Return to the Powerful Daisaku Nogami
vsnet-adm@kusastro.kyoto-u.ac.jp
