(cba:news) New stars for the solstice

Joe Patterson jop at astro.columbia.edu
Fri Dec 13 12:06:42 EST 2002


Dear CBAers,

Time for a report on campaigns.  We have 40 days now on Tau-2, enough to
prove the main signals in the star...  namely the ones I described in my
last message.  It's enough to go to press with.  It was a tough
decomposition, because there are *three* closely spaced frequencies, with
6.488, 6.712, and 6.876 (all +-0.006) c/d, along with the nodal frequency
itself at 0.165 c/d.  Time to sweep the star off the stage.  Thanks to all
who contributed, I know this star gave pretty ugly light curves and I
appreciate your keeping the faith!

A star that gives *beautiful* light curves, but which has only been
discovered by a few of you, is EC04224-2014.  It's high time to attack
this star with vengeance!  Well, anyway... with vigor.  Well placed for
south and north (other than northern Europe), transiting near midnight,
and bright as a sonofagun (about 12th).  Waves of great pulchritude in the
light curve.

I guess we should give up on FY Per.  It is so devoid of activity that we
just can't see anything at our level of accuracy.  Once in a while it
seems to break into 90 minute oscillations, but those occasions are rare
(none this year).  I think I'll send the data off to Jeff Robertson, and
hope that he can make something of it!

We've just started a campaign on V1062 Tau.  This is a tough star, at
~15.6, with a 10-hour orbital period, and besieged monthly by the
rampaging Moon.  But it has a cute 1-hour rotation period, and that
means it's one of OURS.  A fine target for all northerners... and brave
southerners too, I earnestly hope.

Also starting up is DW Cnc.  This star will knock your socks off.  Still a
little early in the season for Cancer, but a good target for morning
observation.  We'll be ramping up the pressure in Jan/Feb.

Finally, there's FS Aur.  Like FY Per, we've not figured this guy out at
all.  It has a 3.4 hour photometric period, but the orbital period is 1.4
hours, and we are basically clueless as to the origin of the photometric
signal.  So, as observers, we need to study it carefully to learn its
short- and long-term coherence.  A pretty good northern target, even for
small scopes since the quantity of interest is that 3.4 hour signal (long
period and decent amplitude means signal-to-noise issues are tractable).

I just taught my last class yesterday.  What a relief to have the pressure
off!  It was a cosmology class, and I taught it historically, which means
that I essentially moved steadily back in time.  Going back to about
t=1 minute, it still seemed like physics... and then it quickly (of
course) turned into theology.  Made me really uncomfortable... nice to
resume thinking about *stars* again.

   joe



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