[vsnet-chat 1640] Re: V1974 Cyg Progenitor

[aah@nofs.navy.mil]

Bob Modic used an HST image to identify the nova and
companion -- a really good idea when such images are
available.  Which filter was used, and was that the
only image available in the archive?  If another
image taken with a different filter were available,
you could transform directly without having to resort
to USNO-A measures.

>..I then measured the intensity of all pixels within a
>5" X 5" area centered on each of
>the stars and summed the values for each.
  I assume you mean 5pixel x 5pixel area, not 5arcsec,
since the companion is within 2arcsec of the much
brighter nova.

I missed Brian's comment:
>     In re the magnitude of the companion star, the value that Modic gives
>evidently from Arne's photometry is almost certainly wrong, both from
>contamination from the nova and from its faintness.
As I mentioned in yesterday's posting, I did not measure the companion
from my CCD frames...the value is purely Bob's from the HST image.
Since this star is also easily visible on the DSS, I think Bob's estimate of
V=18.2 is probably pretty close to reality.

Arne

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