[vsnet-obs 55443] Re: [AVSON] V1830 Sgr Outburst

[arne]

Peter F Williams wrote:
> The dwarf nova V1830 Sgr is in outburst.
> 
> STAR        YYYYMMDD(UT)    MAG    OBSERVER
> 
> SGRV1830    20060729.387        122        WPX
> 
> 
> Looking at the catalogue data, no period is listed for this system.  Based
> on scattered observations given in the VSS RASNZ Publications 10 and 12, a
> period near 11 months is indicated.  More recent closer monitoring suggests
> the period may be closer to 65 to 70 days but the shortest interval between
> what appear to be consecutive outbursts is around 42 days.  VSS Chart 1219
> provides sufficient detail to clearly identify V1830 Sgr and has a sparse V
> comparison between 10.3 and 15.6.
> 
> This star is probably deserving of more attention.
> 
A two-night BV calibration for V1830 Sgr and a Sumner sequence can
be found through the AAVSO chart link, specifically
http://www.aavso.org/cgi-bin/searchcharts3.pl?name=v1830%20sgr
though the AAVSO has no specific charts for V1830 Sgr.
Identification can be either through the VSS chart, or
from the Downes catalog (accessible via VSX).  Note that
there is a 12th magnitude star 8arcsec to the north that
will often cause identification confusion.  For CCD observers,
this is a very crowded field and I recommend inspection of
deep survey plates before believing your photometry of
V1830 Sgr near quiescence.
Arne