Interesting Diffuse green object

Is this an artefact or real diffuse object? Looking more like comet, but I can’t check the single image cutouts at the moment. Not working here.

Weird. JPL thinks it might be a main belt asteroid, but it looks like a comet.
Maybe the image is fuzzy after being stacked with other images.
It isn’t so fuzzy in the single image
1999 BF9** = 2001 QT145

CCD decam r 635971 N28, 125.0 sec (x,y ~ 270,1248)
(decam/CP/V4.1/CP20170331/c4d_170401_041951_ooi_r_v1.fits.fz [59])
(observed 2017-04-01 @ 04:16:56.559349 = MJD 57844.178432)