[vsnet-alert 22589] Gaia18cvi = SDSS J155814.34-163017.3: new WZ Sge type candidate

[Denis Denisenko d.v.denisenko@gmail.com via vsnet-alert]

Gaia18cvi
  20180930.122  13.46G  Gaia
  20180930.196  13.44G  Gaia
http://gsaweb.ast.cam.ac.uk/alerts/alert/Gaia18cvi/

Large amplitude outburst of faint blue SDSS object:
SDSS J155814.34-163017.3
u=21.85+/-0.23 g=21.65+/-0.07 r=21.53+/-0.08 i=21.51+/-0.14 z=21.37+/-0.50

With solar elongation of only 52 deg it is probably too badly placed
for the long time series. But at least it can be confirmed and
followed up visually from Australia.

Historical outburst occured 69 years ago on Harvard plates available
at http://dasch.rc.fas.harvard.edu (FITS header gives DATE-OBS for
Harvard plates as 1949-05-04T21:38:52.8 and 1949-05-20T21:00:00.0,
respectively. Must be local time, not UT?)

DASCH_J155814.4-163017
  19490504.???  13.59B  DASCH
  19490520.???  15.77B  DASCH

The long duration naturally implies a superoutburst in May 1949.

Denis Denisenko