[vsnet-alert 23569] Gaia19efo = ASASSN-19xi - eclipsing dwarf nova in Pavo

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

Gaia alert team has reported this transient in Pavo on Sep. 23:
http://gsaweb.ast.cam.ac.uk/alerts/alert/Gaia19efo/

Gaia19efo
  20190829.1450  17.65G
  20190921.1033  15.79G  Outburst
  20190921.1773  16.53G

Position on Sep. 2019 (J2000.0): 19 28 30.02 -74 10 53.3
Gaia corrected J2000.0 position: 19 28 30.03 -74 10 53.1
Distance modulus (m-M)=10.0, Gmag=17.88, M_abs=7.88, BP=18.63, RP=16.94

ASAS-SN (Shappee et al., 2014) has reported the same object on the
same day as ASASSN-19xi, but with the discovery date stated as
2015-05-11.24 and the following photometry:

ASASSN-19xi
  2019-09-18.16  >175g
  2019-09-18.22  16.8g
  2019-09-20.02  16.6g
  2019-09-21.21  16.8g
  2019-09-22.21  16.2g
  2019-09-23.74  16.3g

Past outburst nearly 10 years ago in Siding Spring Survey data via
CRTS (Drake et al., 2009):

SSS_J192830.1-741052
  20090929.4270  15.76CV
  20090929.4462  15.83CV

Gaia photometry (after removing the points in outburst) gives the
eclipsing light curve from 17.6 to 18.3m with the period either
0.1248492 d or 0.249698 d (double value). Time-resolved photometry
from Southern observatories is required to refine the period.

Preliminary eclipse ephemeris assuming the shorter value:
T_min = 2458486.761 + 0.1248492 * E
Eclipse duration is unusually long, about 20 per cent of the short
orbital period (or 10 per cent of the long one).

VSX entries:
https://www.aavso.org/vsx/index.php?view=detail.top&oid=1498422 - Gaia10efo
https://www.aavso.org/vsx/index.php?view=detail.top&oid=1498427 - ASASSN-19xi

Denis Denisenko