[Aavso-photometry] some nova and CV updates

[arne]

GW Lib (WZ Sge type) has just
transitioned from small amplitude fluctuations to 0.1mag P-P amplitude
superhumps.  Pretty cool.  This is early stages of the development,
so getting additional time series is important in understanding
these stars.  The early superhumps were seen by Shawn Dvorak
and Arai Akira (KANATA Observatory), with period around 0.0540 day;
they are also clearly visible on the Sonoita dataset from this
morning (070423 UT).

V5558 Sgr, a nova only discovered a few days ago, was studied
by the Asiago and the Japanese NAYUTA groups.  Their spectra
indicate that the emission line widths are quite small, and
that FeII, MgII, SiII, NII lines are being seen.  This, coupled
with the large outburst amplitude, makes this nova extremely
interesting to the researchers.  If you can take time and monitor
this nova, it would be useful.  We still haven't had any clear
weather at Sonoita, but Mati Morel has created a visual sequence
for this field, but it has not been uploaded to VSP yet - give
us another day or so.  Be *very* careful about the companion
star that is about 5arcsec NW of the variable - it is comparable
in brightness at the red bandpasses, so will influence your CCD
photometry.  It continues to brighten, so expect this object
to get even brighter in the next few days.

I also wanted to mention, for our Southern observers, Arlo Landolt's
latest standards paper is now available on the Astronomical
Journal webpage as an e-First article:
"UBVRI Photometric Standard Stars around the Sky at -50 Declination",
AJ Volume 133, page 2502.

Good luck and clear skies!
Arne