That is partly because it is obscured by the gaseous nebula ejected in that explosion.
From the economist.com
This stage ends when the star ejects its layers, forming a gaseous, faintly glowing nebula.
From the newscientist.com
The glowing gaseous shrouds in the nebula were shed by the central star after it ran out of fuel to sustain the nuclear reactions in its core.
From the denverpost.com
Astronomers speculate that the interaction between these two stars may have sparked episodic outbursts of material, creating the gaseous bubbles that form the nebula.
From the sciencedaily.com
A deep exposure shows everything from dark nebula to star clusters, all imbedded in an extended patch of gaseous wisps in the greater Orion Molecular Cloud Complex.