  The classical nova V5583 Sgr (Nova Sagittarii 2009 No 3) has been observed
during the rise phase and shortly after by NASA's STEREO/HI instruments, with
later optical spectroscopy obtained with the R-C Spectrograph at CTIO, Chile.
The time of peak in the STEREO passband has been constrained to within 4 hours,
as a result of the high cadence data obtained by STEREO/HI. The optical spectra
show the nova evolving from the permitted to the nebular phases. The neon
abundance in the ejecta is [Ne/O] > +1:0, which suggests that V5583 Sgr was
most likely a neon nova.
