(cba:news) superhumping stars

[Joe Patterson]

Dear CBAers,

I'm about to leave for the Washington AAS meeting... where I'll have email
but vastly reduced analytical powers.  I wanted to sound the bugle on two
shiny new superhumpers, though.

We (Eve Armstrong and Tyler Harris) managed to get a brief run on Ha
0242-28 ("For" in the Downes catalog)... which confirmed the presence of
superhumps, suggested by Berto in his second announcement on this star.
We need 1-2 more days for a decent period estimate, and the
star is not well-placed... being buffeted by encroaching moonlight and
sunlight.  But I hope you - especially southerners - can cover this star
as long as possible.  The only hope, given the bad placement, is to have
many longitudes pulling together on this one.

The other is SDSS0407-06 = Eri in the Downes catalog.  Our data mostly
confirm the claim of Ak et al. (2005) announcing a negative superhump.
This one's due to Bob Rea and Tom Krajci.  But this star is fairly well
placed - with the season not too far gone, and nicely astride the
celestial equator.  So we'd love to get a few more WEEKS of coverage
before saying goodbye for the year.

These stars, both deep eclipsers, could turn out to be extremely important
- because of the extra diagnostics afford by that nice knife-edge cutting
across the superhumping light source!

And at 9 hours RA, it's now the season again for T Pyx in the south, and
DW Cnc in the north!

joe