[vsnet-alert 22133] ASASSN-18je - eclipsing dwarf nova in the period gap

Wed May 2 19:28:52 JST 2018

ASAS-SN has detected this object in Centaurus in outburst on April 30:

ASASSN-18je
  20180427.22 <17.1g  ASAS-SN (Shappee et al., 2014)
  20180430.16  15.5V  ASAS-SN
  20180430.88  15.9g  ASAS-SN

Position from ASAS-SN Transients page: 13 08 05.07 -41 46 23.8
http://www.astronomy.ohio-state.edu/~assassin/transients.html

The variable was observed by Siding Spring Survey with multiple
outbursts (at least seven in 2006-2009, but none in 2010-2013). The
brightest one was detected in April 2006:

SSS_J130805.0-414624
  20060409.5313  14.95CV  CRTS (Drake et al., 2009)

Light curve from CRTS:
http://nesssi.cacr.caltech.edu/cgi-bin/getcssconedb_id.cgi?ID=3041075023044&OUT=csv&SHORT=short&PLOT=plot

Outside the outbursts the variable is showing V-shaped eclipses
superimposed on the sine wave. The orbital period is 0.105329d (2.5277
hr, or 151.66 minutes), in the period gap. Amplitude of the orbital
hump is about 0.8m (17.4-18.2), the eclipse minimum is 19.4m. Maximum
is around the orbital phase -0.14.

Position of ASASSN-18je in the period gap of cataclysmic variables:
http://scan.sai.msu.ru/~denis/ASASSN-18je-CV-period-gap.gif

The variable is an UV source GALEX J130805.0-414624 (FUV=19.99+/-0.14
NUV=19.66+/-0.08 from GR6/7)
http://galex.stsci.edu/GR6/?page=explore&photo=true&objid=6387522792001110583

IDs in other catalogs are available from Vizier. For example:
USNO-B1.0 0482-0308006 (B1=N/A R1=17.56 B2=18.54 R2=18.12 I=17.86)
2MASS J13080502-4146242 (J=16.33+/-0.12 H=15.82+/-0.16 K=N/A)
WISE J130805.01-414624.4 (W1=14.97+/-0.04 W2=14.66+/-0.06
W3=12.16+/-0.21 W4=N/A)
AllWISE J130805.00-414624.4 (W1=14.82+/-0.03 W2=14.63+/-0.05 W3=N/A W4=N/A)

PPMXL position (Epoch 2000.0): 13 08 05.026 -41 46 24.22
Gaia DR2 position (Epoch 2015.5): 13 08 05.018 -41 46 24.48
Gaia parallax: 2.688+/-0.117 mas (distance 372+/-16 pc)

Color-combined finder chart from DSS:
http://scan.sai.msu.ru/~denis/ASASSN-18je-JRIR.jpg (10'x10' FOV).

Observing run at iTelescope T31 in underway until 11:30 UT. Further
observations are encouraged.

Denis Denisenko