Tue, 10/09/2012 - 19:21
It appears that Z UMI is undergoing one of its deepest minima (below 18th mag). I have seen that there are a few observers that reguraly follows this RCB star. Since I have leraned that the minima are particularly important to determine the physical properties of RCB stars I wonder whether the AAVSO has given notice to professional astronomers and if there are some of them that are currently taking the spectrum of Z UMI.
Gianluca
These deep minima are indeed scientifically valuable - they allow a close examination of the environment of the R CrB variable when adaptive optics are used.
Cheers,
Doug