[Aavso-photometry] V5558 Sgr: rising rapidly, new comp stars

[Matthew Templeton]

Hello all,

V5558 Sgr appears to be rising beyond the current bright limit of 7.6 as 
of JD 2454281.0 and new comparison stars are now needed.

You may plot a 4 degree (240 arcmin) chart for V5558 Sgr using VSP:

http://www.aavso.org/observing/charts/vsp/

Please raise the magnitude limit of the chart to 9 or brighter when 
creating large charts.

The larger chart will give you a 7.4 mag comparison star for WZ Sgr which 
is within a few degrees of V5558, and you may also use the following 
bright comparison:

HD 167771: V=6.54, (B-V)=+0.12  (note, these are Johnson BV, *not* Tycho)
RA: 18h 17m 28.557s 	Dec -18d 27' 48.42" (2000)

It is about half a degree NNE of WZ Sgr.  It is listed in the catalog as a 
double, but the companion is several magnitudes fainter and should not 
affect observations.  It is also very blue, but there aren't many other 
good choices in that part of the sky.

We will add this star to VSP as soon as we are able.

Clear skies,

Matthew Templeton
AAVSO