In 2008, an investigation of the Southern Crab with its symbiotic (astronomical term) star was published. The study used imaging and spectroscopic data from space and Earth-surface telescopes including Hubble and VLT observatories.
The ESO defines a symbiotic star system as "binaries in which a small hot star (white dwarf or main sequence star) orbits around a red giant star. These systems are often surrounded by an envelope of gas or dust; those with gas are known as  S-types and those with dust as  D-types."