ESO-HA 1830 = Gaia23bjz: unusual large-amplitude emission-line object

http://gsaweb.ast.cam.ac.uk/alerts/alert/Gaia23bjz/

Amplitude 0.8 mag. Not irregular and several candidate periods are present in ATLAS data (such as 0.4644 d).

2MASS 054545.493 -075401.77 (2000.0) 13.555 12.452 11.616 054545.4 -075401 (2000.0) ATOJ086.4395-07.9005 dubious c=18.328 o=16.766 P(LS)=1.205589 rms=0.48 054545.495 -075401.81 (2000.0) Gaia_DR2_3012764080328211712 plx=2.140(0.186) dismod=8.3 pmra=1.277(0.327) pmdec=-3.659(0.309) G=18.029 BP=19.273 RP=16.694 054545.495 -075401.82 (2000.0) Gaia_EDR3_3012764080328211712 plx=2.279(0.128) dismod=8.2 pmra=1.364(0.107) pmdec=-2.873(0.105) G=18.142 BP=19.137 RP=16.707

The object is in M42 region and the distance is the same. Proper motions are different. (But apparently not a CV)