(cba:news) Novae with lessons to teach us...

Joe Patterson jop at astro.columbia.edu
Sat Jul 9 07:19:39 EDT 2022

Hi CBAers,

There are two classical novae, arguably, which have had a titanic effect 
on humans' ideas of what novae actually are: DQ Her (1934) and T Pyx 
(1890 and six more times).  The 1954 report that DQ Her was an eclipsing 
binary with an "incredibly short" orbital period of 4.6 hours changed 
all our ideas about novae.  T Pyx was the first RECURRENT nova found, 
and showed that a nova was a natural event in the lifetime of a close 
binary (with a white-dwarf component).

I believe that V1674 Her will take a place in this pantheon.  Why?  We 
already know that it's the fastest nova in history,which suggests that 
it erupted from a WD of very high mass.  So far, everything about this 
star announces SPEED: the speed of the ejected shell; the speed of its 
light-curve evolution, the speed of its spin-period change; the speed of 
its orbital-period change. Even OUR speed in getting out an initial paper.

I had hoped that sending out a preprint of our Paper I would help 
motivate observers to keep the faith on it.  At magnitude 17.0 and with 
a large-amplitude (0.1 mag) 8-minute signal, it's still within reach for 
all CBA observers - and easy reach for many.  But the flow of data has 
virtually stopped.  Maybe your light curves seem very ratty to you;  but 
this is probably because with the integration times you're probably 
using to get decent S/N, the data look like noise.  But it's very likely 
SIGNAL.  With an 8-minute *coherent* signal, sampling just 4x per cycle 
is PERFECTLY suited to define its properties, even though the data won't 
look good (considering counting statistics, background light, etc.)

   The star is near opposition now, and I'm super-eager to continue work
on this star through October - and finish a second paper which will 
establish a full ephemeris for the rapid pulses (+ the orbit).  Until it 
drops to mag 19 or so, it will remain a GREAT target.

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