[vsnet-chat 7412] Re: [AVSON] T Cen Reduced Amplitude at Minimum

[Sebastian Otero]

Hello, Peter,

> Recent visual observations of the bright semi regular variable T Cen 
> suggest
> the current cycle of this star has a greatly reduced amplitude.  It has
> risen from a shallow minimum near magnitude 8 during early March to a
> relatively faint maximum of 6.8 during the latter part of April.  The next
> minimum is expected in early June but T Cen has shown little variation 
> from
> 6.8/6.9 during the past 6 weeks (April 2 through May 14).
>
> T Cen most recently exhibited a similar reduced amplitude at minimum for
> just 1 cycle in 2006 September.  It has a normal visual range of about 3
> magnitudes (approx 6 to 9).

T Cen has been showing a kind of RV-like behaviour since several years ago 
(maybe before, I am only referring to my own observations and ASAS data). 
Maybe now this seems more evident but deep and shallow minima use to 
alternate. A small hump in the ascending branch to one of the maxima also 
seems to be a recurrent feature.
Maybe the current cycle will have a shallow minimum but the star is fading 
right now so I don't see an indication of that yet.
The recent maximum took place around April 15-20 at V= 6.0 and by May 15 was 
at V= 6.5.
I have updated the lightcurves on my website also including ASAS-3 data that 
show the behaviour mentioned above.
http://ar.geocities.com/varsao/Curva_T_Cen.htm
For ASAS data alone:
http://www.astrouw.edu.pl/cgi-asas/asas_variable/134146-3335.8,asas3,90,1870.610000,600,200

Cheers,
Sebastian.