[vsnet-campaign-be 205] BU Tau brighter?

[Petr Harmanec <hec@sunstel.asu.cas.cz>]

Dear Colleagues,

      I do not understand what you are reporting here. For at least three
years BU Tau is in its undisturbed state with V=5.04 mag. according
to our unpublished Hvar and SPM photometry.

   Since BU Tau is an object with an inverse correlation between the
brightness and emission strength according to my classification, it means
that its envelope is currently weak and inactive. Only
a   d e c r e a s e   in its brightness would mean that a new envelope is
being built and be worse of an alert. The currect brightness corresponds
roughly to the true brightness of the central star, unaffected by a
contribution from an envelope.

(For details of the correlation see, e.g., 
Harmanec 1983 Hvar Obs. Bull. 7, 55 or my recent 
Harmanec 2000 Alicante IAU Col. 175 review - both available from ADS.)

  A pleasant and successful year 2003 to everybody!

                 Best wishes,
                                         Petr Harmanec


On Sun, 22 Dec 2002, Taichi Kato wrote:

> BU Tau brighter
> 
>   YYYYMMDD(UT)   mag  observer
>   20021127.553    60  (Yoshitoshi Atobe)
>   20021128.594    52  (Yasunori Watanabe)
>   20021203.006    51  (Sebastian Otero)
>   20021208.058    51  (Federico Claus)
>   20021209.843    51  (Maciej Reszelski)
>   20021209.976    52  (Pavol A. Dubovsky)
>   20021210.007    50  (Sebastian Otero)
>   20021210.040    50  (Federico Claus)
>   20021210.608    52  (Yasunori Watanabe)
>   20021210.740    51  (Pavol A. Dubovsky)
>   20021212.039    50  (Federico Claus)
>   20021212.678    52  (Yasunori Watanabe)
>   20021215.053    50  (Sebastian Otero)
>   20021217.044    50  (Federico Claus)
>   20021218.628    52  (Yasunori Watanabe)
>   20021220.044    50  (Sebastian Otero)
> 
>