Re: (IAAC) Obj: Aldebaran (alpha Tau)

From: Lew Gramer <dedalus@latrade.com>
>But I also caught an even more startling event - a *fading*.
>Not a DISAPPEARANCE, but a brief partial reduction of about
>two magnitudes in Aldebaran during a clear moment! I am not
>sure, but this seems to imply that a lunar feature occulted
>a *portion* of the supergiant's 0.03" disk... unless it can
>possibly be explained by some refractive effect from the
>lunar limb??
>At any rate, the gradual ingresses plus this bizarre fade made
>me feel this was a log worthy of being submitted to IAAC! This
>is the sort of subtle thrill that makes this hobby worthwhile.
Hi, Lew - last year in the springtime, around Hale-Bopp time, several SF 
Bay Area astronomers watched a near-bullseye occultation of Aldebaran by 
Luna and saw something really similar to what you described - a brief 
dimming of the star by maybe just about 2 mags for several seconds 
before it winked out. It was a step-wise fade, with an instant decrease 
to a lower mag "plateau" followed seconds later by instant complete 
obstruction. The effect was *very* pronounced in 10x50 binoculars, my 
glass of choice.  The dimming was seen from many locations around the 
Bay; I don't recall hearing a definitive explanation from anybody, and 
it seems still a mystery.  It would be great to see if anyone else noted 
the dimming that you saw as well.
Bruce Jensen
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