[vsnet-chat 4843] Re: [AAVSO-DIS] Re: "Unknown" Variable Stars

[Thom Gandet <tgandet.EXSPAM@mindspring.com>]

Brian and John,

   Thanks for the information re HD 37519.  The claim of a two
magnitude flare was definitely attention getting!

   While I was aware of Andrews's paper, I can't get at it, so I am
grateful to you for providing the gist of it.  That's what I was
looking for.  Many thanks also to John for the Zinner reference.

> I'm pretty familiar with these services since I use them daily...

   I'm also pretty familiar with them and use them successfully
nearly daily.  (I'm not exactly the Horowitz of SIMBAD however!)
But I apparently implied (but most assuredly did not intend to say)
that there was nothing to find using on-line resources.

   Since my maladroitly worded query moved Brian to comment, there are
undoubtedly others who read it as he did, so I want to set the record
straight about it:  I was unable to find only the references to the
first announcements of variability and what those claims were (i.e.,
instrumentation and mag range).

   That was the intended, very limited, extent of my question.  The
prodigious collective memory of the AAVSO and VSNET contributors
seemed like the next logical step to look for it.
  
   Furthermore, The SIMBAD query form does not recognize NSV 2537
or NSV 11504 (which John kindly pointed out is the right designation
for delta-1 Lyr).

   I did, of course, locate NSV 2537 via VizieR (in II/219/nsv),
but the reference key to the original paper there (i.e., 2690) does
not appear, as I thought it would appear, in the reference list
(II/219/refs).  Perhaps I've overlooked something there.  In any
case, I was stumped and pressed on to...here.

   NSV 11504: Never trust an "unimpeachable source" (not myself, in
this case) - they, too, shall suffer from typos! <G>  With the
correct NSV number in hand, I found the Zinner reference ok.  But
here I had failed, amazingly, to simply enter del01 Lyr into the
GCVS search window!  Sheesh.  (The search window ought to recognize
NSVs!)

   Some of the PEP eclipsing binary observers may find Delta-1
Lyr an interesting target, as there is good reason to believe it
is an eclipser. It is an SB1 with a large mass function.  The SB1
orbit paper from the 1950s refers to it as having been suspected of
variability, but does not give the source or a magnitude range.
There is evidence from the radial velocities of secular change in
the orbital elements, but which may also be due to line-blending
effects with a possible secondary spectrum.

   On that basis, I did some PEP on it in the early 1970s and
caught what looked like a 0.3 magnitude dip (in V) near the time
of predicted eclipse.  I was never entirely convinced that it
wasn't due to equipment problems (or to the ubiquitous lousy skies
in Eastern Kansas!

   But there's been a nagging doubt about it since.

   I wanted to hear about the variability question from the
"horse's mouth", so to speak:  If the observed range was >~0.2 mags,
then calculating phases for the 120-odd Hipparcos observations might
be useful.  West's observations (which I knew about) and the
Hipparcos data indicate constancy, but with the system's long-period
of ~89 days, eclipses could easily have been missed by observations
over a short time interval or spaced in time in an unlucky way.

   Thanks for your help, and I apologize for the confusion.


Cordially,
Thom Gandet


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