From tem@sai.msu.su Mon Nov 11 01:02:45 1996
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Date: Mon, 11 Nov 1996 03:02:17 +0300 (MSK)
From: "Eugene M. Trunkovsky" <tem@sai.msu.su>
To: Andrea Richichi <richichi@arcetri.inaf.it>
Subject: Occultation curves of Aldebaran
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....omissis....

	Now I send you occultation curves of Aldebaran in the form of a
PostScript file. On the vertical axis some conventional counts (per 1
ms) are shown. The curve "B" (at the bottom of a picture) is the curve
which is produced from the real record of the flux in the band "B" by
calculating the smoothed average; as you can see it does not show
practically entirely any evident signs of the flux drop due to the
occultation process. Therefore we can consider in the first
approximation the flux changes in this curve as the result of variable
clouds (in general, of variability of atmospheric transparency), of
scintillation and also of the changes of background intensity.
	On the other hand you can see quite clearly in the curves "R"
and "V" (at the top of a picture) which were recorded in the bands "R"
and "V", respectively, some decrease of the flux due to the occultation
(near values 5800-5900 in the time axis); and also one can see clearly
that these curves are very similar to each other, practically most of
flux changes coincide in detail, therefore we can consider that they
contain information both about occultation as itself and about all
atmospheric and background effects. These curves are shifted along
vertical axis so that it would be more convenient to look at the
picture. Besides many details in the curves "B" and for instance "R"
are also very similar. Thus if we subtract the curve "B" from the
curve "R" using some suitable linear coefficients, i.e. if we construct
some suitable linear combination of these curves we can obtained some
resultant curve which corresponds in the main only to the occultation
phenomenon. Such a curve is shown in the picture as third from the top.

	Of course this is only very tentative examination of the data,
but I think that the resultant curve looks like quite reasonable.


.....omissis.....