What exactly was this 'interstellar visitor'?

By Ashley Strickland, CNN

Updated 1701 GMT (0101 HKT) June 27, 2018

This image shows the vicinity of the Tucana II ultrafaint dwarf galaxy, captured by the SkyMapper telescope.
Photos: Wonders of the universe
This image shows the vicinity of the Tucana II ultrafaint dwarf galaxy, captured by the SkyM