[vsnet-alert 23032] ASASSN-19ds: unusual object

[Taichi Kato]

ASASSN-19ds: unusual object

ASASSN-19ds 	--- 	------- 	11:5:29.46 	-40:7:8.2 	2019-02-28.3 	15.12 	SDSS 	DSS 	VIZIER 	------- 	CV candidate, matches to GAIA DR2 G=15.4, highly variable in CRTS, g>18.0 on 2019-02-25.33, g=17.2 on 2019-02-26.10, g=15.6 on 2019-02-27.18, g=15.5 on 2019-02-28.30.

ASAS-SN data:
https://asas-sn.osu.edu/light_curves/ba76f7cb-2164-4fde-b6a4-e8574277692d

IDs:
110529.486 -400708.62 (2000.0) Gaia_DR2_5390485501841902592 plx=1.696(0.040) dismod=8.9 pmra=-13.814(0.049) pmdec=1.151(0.052) G=15.375 BP=15.467 RP=15.127
110529.481 -400708.33 (2000.0) GALEX_DR5_6386221041096590545 NUV=16.162(0.021) FUV=16.287(0.036)

   The CRTS and ASAS-SN light curves resembles a Z Cam star
with very long standstills.  Dwarf nova-type outbursts
in 2018 April in the ASAS-SN data.
The object, however, looks too faint (M_V = +6) in
standstill and too blue (G-R= +0.3).  The orbital period
may be short.  Time-series and spectroscopic observations
will be interesting.