[4] Follow-up observations with instruments on the Gemini Observatory and the Very Large Telescope revealed the secondary, the brown dwarf SDSS 1557B, and a circumbinary disk around the binary.

The fact that SDSS 1557B is tidally locked creates vast temperature changes in the dayside and nightside of the brown dwarf.

[4] The system also displayed high metal abundances (Ca, Mg, Si), showing that the white dwarf was polluted with planetary debris.

[7] The system formed at least 1.5 Gyr ago as a low-mass-ratio binary of a star (1.06–1.85 M☉) and a companion with a semi-major axis of less than one astronomical unit (AU) in the past.

Around 33 Myrs ago the common envelope was ejected, forming a low-mass Helium core white dwarf.