From: "Walt Cooney" <waltc
Date: Wed, 15 Mar 2006 15:21:26 -0600
Importance: Normal

Hi folks,

Fascinating subject.  You got me interested.  We had decent skies in Baton Rouge
when I combined them, I would get some improvement in my resolution through
dithering.  I see the triplet clearly.  The variable and the 13.7 magnitude star
are elongated single object.  The 16.7 mag star has a little more separation.  I
don't have any PSF software but just eyeballing the magnitude from the height of
the "hump" that is Z Tau, I'd estimate a magnitude between 14.5 and 15 for Z
Tau.  Anyone handy with PSF fitting want to look at the summed image?  I can
email it to you.

Clearest skies,
Walt Cooney

Sent: Tuesday, March 14, 2006 12:49 PM
To: aavso.id.bve


Erwin van Ballegoij wrote:
> FYI,
>
> I came upon this discrepancy when one member of our association reported
> Z Tau to be around magnitude 14 (visual estimate), while another member
> of our association reported this star to be fainter than magnitude 16.9
> (CCDV measurement) at about the same time.
>
I should also say that the reason I looked at this field in 2001/2003
was that the Chart Team had questions.  Mike Simonsen on March 4, 2003

the charts. There is a note regarding the companion but it does not indicate
where it is.
Observers should be aware of this when making estimates as it
fades to near or below the magnitude of the companion (like now). If you
only see one star you are probably reporting a combined magnitude.

I wrote on Dec 31, 2003 to the chart team:

The magnitudes and positions of the triple are:

North  05:52:25.08  +15:47:48.0  13.734  0.392
Z Tau  05:52:24.85  +15:47:43.8  13.689  1.609
South  05:52:24.78  +15:47:37.6  16.686  0.800

with magnitude errors of about 0.03mag since only a single night
of photometry went into the ztau.dat file (internal errors are
under 0.01mag).  HJD for this observation is 2453002.8536.
Coordinates have 100mas errors.

I hope this gives enough information for folks observing the field.
Arne
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