[vsnet-chat 1617] Re: FASTT-2 variables (Kaiser)

[Taichi Kato <tkato>]

From: dhkaiser@sprynet.com (Dan)
To: bas@lowell.edu (Brian Skiff)
Cc: aah@nofs.navy.mil, aavso-discussion@physics.mcmaster.ca,
        vsnet-chat@kusastro.kyoto-u.ac.jp
Date: Sun, 07 Feb 1999 14:35:02 GMT
Message-ID: <10001617@hoge.baba.hajime.jp>
References: <199902060317.UAA15953@zwicky.mars_hill>
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Subject: [vsnet-chat 0] Re: [AAVSO-DIS] Re: FASTT-2 variables
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	Having a fair amount of blinking experience myself, I must agree
with Brian.  Less than 0.5 mag is very difficult to detect while blinking
photographs.  I conducted a photographic patrol for 10 years, 1987 - 1997.
Although not with professional equipment, and far from having complete sky
coverage.  After comparing several thousand pairs of photographs there were
only about 40 discoveries, all in the 7th - 11th magnitude range.  Only one
with less than 0.5 mag amplitude.  The smallest amplitude was about 0.4
mag, V1061 Tau.  Most were in the 0.05 - 1.0 range.  The Hipparcos
satellite discovered over 5000 new variables in the same magnitude range,
11th and brighter.  This is one of the reasons I retired the patrol.
However I'm sure there are more there to be found, it will just take more
effort for fewer results.  There are still plenty of long period eclipsers.
An example is my  4th discovery, 8th mag OW Gem, which eclipses once every
3 1/2 years.  And there will always be novae, something I never did find.  

Dan

On Fri, 5 Feb 1999 20:17:12 -0700, you wrote:

>     Having blinked a fair number of Pluto Camera plates (33cm astrograph
>that was used to discover Pluto, similar to what the Sonneberg/Heidelberg
>groups used), I would concede that variables with full amplitudes under 
>0.5 (at least) are not at all obvious.  Slight differences in seeing and
>effective exposure can readily mimic variability.  Generally those guys
>(well, Hoffmeister---what percentage of the known variables did he find?!)
>didn't report things with amplitudes less than ~0.6 or 0.8 mag.  Pojmanski's
>quick survey with a 135mm telephoto showed that even for stars brighter than
>mag. 10-11, less than half were known in the areas he looked at.
>     Sounds like FAST will be giving the Moscow GCVS group plenty of work
>to do, especially if you'll be supplying lightcurves downstream.
>
>\Brian

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