Date: Tue, 14 Mar 2006 08:02:06 -1000
From: "James Bedient" <jbedient
References: <200603140906.k2E96OU5030689
	<4416C35C.9090301
	<7.0.0.10.0.20060314152618.01ae1ec0
	k2EI25Mn004346

Is there a faint CCD sequence anywhere for Z Tau?

> >Bob Wing wrote:
> >>Date:    Monday night, March 13-14, 2006
> >>Dear Rick, Erwin, et al.,
> >>
> >>The real problem is that if Z Tau gets much fainter than the companion,
> >>as it probably does, then only one star is visible, at approximately
> >>the right place, and the companion is likely to be misidentified as
> >>plot the companion on the chart, if the scale permits.  Then if the
> >>observer sees only one star, he/she will have to think consciously
> >>about which one it is.  Erwin mentioned that the companion is shown
> >>This is of some importance because Z Tauri is an interesting star.
> >>its mean light curve with an extraordinarily long period of 495 days
> >>The GCVS (I'm looking at the 4th edition, 1987) gives its period as
> >>type as S7.5,1e, which presumably refers to a phase near maximum light.
> >>are present in the spectrum in addition to the dominant TiO bands).
> >>Interestingly, this is very similar to the description of Chi
> >>visual amplitude of any Mira on record (10 magnitudes!).  In fact,
> >>they generally
> >>V = 17 or even 18.  It would be nice to know.  Observing it at minimum
> >>will be challenging, but doable with a CCD with sufficient scale to
> >>separate the two stars (I don't know the separation).
> >>Mira near minimum light provides an opportunity to observe an extremely
> >>cool (by stellar standards) gas, which is bright enough to be observed
> >>spectroscopically (at least in the infrared).  At low temperatures one
> >>sees molecules that are not present at warmer phases.  And with the
> >>molecules that have never been seen in any star.  It was in just such
> >>Miras) that bands of zirconium sulfide (ZrS) were first identified.
> >>So let's get after Z Tau and see how faint it actually gets.  I
> >>just downloaded Bulletin 69 (Predictions for 2006) and see that Z
> >>Tau (0546+15A) is listed as "urgently in need of observation."  It
> >>had a predicted min last January 19, so it won't have another one
> >>until April of 2007.  But it's still faint now, and there should
> >>still be a chance
> >>this year, before it goes behind the sun, to observe it while it's
> >>significantly fainter than its companion.
> >_______________________________________________
> >