Comment on WS statistic selected variables in TASS data CD 23

[jg <jg@jgws.freeisp.co.uk>]

wsv3.pl was run against collected.big from CD 23.

The resulting datafile was sorted in order of decreasing Welch-Stetson
statistic.

I have now examined the first 63 of these, inclusive of all objects of
WS > 13.  The stopping point was arbitrary.

Out of these 63 objects 6 where already known to the GCVS (including the
"top 4"), consisting of 3 delta Cepheids, 2 eclipsing binaries and one
semiregular star.  Also, one further object was already listed in the
NSV supplement, making 7 pre-identified variables.

About 10%.

I've managed to resolve the data for 3 of the stars not previously known
for variability, giving period and amplitude range and suggested
classification.

About 5%.

I have been able to identify 25 stars as being variable, but with
insufficient data to be explicit about their full period or amplitude,
so I am categorizing these as "suspected variables", and they will be
presented in a separate post.  This list doesn't include the 3 resolved
objects mentioned above, which I consider as nearly being sufficient to
publish upon individually, and so have posted separately as I came
across them.  Nor does it include three or four objects mentioned by
other people, and which are being observed by people at the moment (eg
Michael Koppelman.  NB I've tried not to encroach on others here, sorry
if I've included an object someone already detected and I missed the
fact).

25 + 3 or 4 from others is about 45%

So, 25 + 3 + 3 + 7 = 38.

That is around 60% of the 63 stars from TASS CD 23 with the highest
Welch-Stetson statistic can be said to be variable.

Of the remaining 40% there may well be many variables still remaining,
but it is difficult to be certain whether the variation is real or
noise.  However, some single night runs of only a couple of hours that
look just like scatter of less than 0.05 amplitude range did give a
large WS statistic.  Then again, they could still be low amplitude
variables at the edge of detectability.  Then again, again, they could
be just noise.


Cheers

John

JG, UK