(cba:news) v1101 aql, v1974 cyg, v1494 aql, cc scl, GD 552, V1223 Sgr

Joe Patterson jop at astro.columbia.edu
Sun Aug 17 19:34:32 EDT 2014


Dear CBAers,

      Time for a report on targets.  We've gone 33 days, missing only 3, 
on V1101 Aql... and the light curves are beautiful.  However, the star 
is about to rise from 15.5 to its high state around 13.9 - and we've 
never really caught the transition (it seems to occur in ~1 day).  We 
need to stay on this star just ~4 more days to be sure of catching it.
Kudos to Tomas Gomez and Joe Ulowetz for doing the heavy lifting on this 
star!

     The coverage on V1494 Aql has also been superb.  The orbital 
waveform is very well defined, including the eclipse, and a superhump 
has appeared.  BUT there's an interloper star just 1.5 arcsec away from 
V1494 Aql.  We can't distinguish it, but we can try to minimize it by 
using a B filter.  The critical need is to find out just how deep the 
eclipse is.  It's mighty deep; the star is somewhere around 18.5 mag at 
mid-eclipse.  A few decent eclipses will do the job, if you can manage 
at that brightness.

    With our recent stress on classical novae, it's time now to do V1974 
Cyg (+ N Cyg 1992, the "nova of the century").  Especially now, in the 
dark of the moon.  Another tough target - 17th mag - and we need a 
several-week campaign.  The idea is to measure the phase of the orbital 
signal; it's pretty subtle, normally dominated by the superhump - but 
with enough coverage, we should be able to extract the orbital wave 
(about 1.9 hours).  Long runs needed, clear filter.

    And finally - for the north - there's GD 552 = Cep 1 in the Downes 
et al. catalog.  About 16.4, and we've never managed to catch the 
orbital signal.  And, for that matter, neither has anyone else. 
Probably the oldest CV in the sky.

    In the south, we want to continue on V1223 Sgr and CC Scl, and start 
up a campaign on VZ Scl (already started by Gordon).

    Then there are the dwarf novae.  I'll study them and comment later!

joe

v1494 aql - b,

v1974 cyg

v1101 aql

cc scl

gd 552 cep 1
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