(cba:news) HZ Puppis and friends

Joe Patterson jop at astro.columbia.edu
Mon Jan 13 13:11:56 EST 2014

Dear CBAers,

We have found stable 21 minute oscillations in the light curve of the 
old nova HZ Puppis (1963).  This had been reported by Abbott and Shafter 
a long time ago (1997), but never studied again or verified - even by 
them.  Abbott and Shafter are extraordinarily reliable observers... but 
it was just a conference proceeding, and such things are usually 
preliminary reports, which are followed by proper scientific papers.  No 
paper followed, by them or anyone else.  And being a northern guy, there 
wasn't a lot of chance for me to follow up.  Then we did, a few days ago 
- and there it was: beautiful 21 min oscillations, just as advertised.

So far our data is only from Kitt Peak, and we desperately need coverage 
from other longitudes.  With dec=-28 we can't stay on the star very 
long, so aliasing is rather severe.  This is all the more so because the 
orbital signal is very weak in this star.

The star is around V=17.2.  Easy for us with a 2.4 m, but the 
oscillations are usually pretty strong, and our main reliance on 
off-longitude data is alias rejection.  So long runs at other longitudes 
would be wonderful!

There's a lot of competition from other southern novae in the Jan-Feb 
sky.  Namely T Pyx, CP Pup, and V382 Vel.  I *think* we're done with CP 
Pup.  It's the most mysterious and complex of all CV light curves I've 
ever seen... and normally I'd be begging for more data.  But I can't 
imagine getting coverage any better than we had in 2012 and 2013 - so 
for the moment, it's off the menu, and I have a big homework assignment. 
  T Pyx is definitely on the menu, and probably V382 Vel (though more on 
that in a few days).

Let me know if you manage to obtain a good long time series on HZ Pup. 
This will affect our priorities in the 2.4 m run, since alias-breaking 
is aided by the *proximity* of data at different longitudes.  Thanks!

joe p
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