APM 08279+5255 was initially identified as a quasar in 1998 during an Automatic Plate Measuring Facility survey to find carbon stars in the galactic halo. The combination of its high redshift and brightness made it the most luminous object yet seen in the universe.

Constellation: Lynx

Apparent magnitude (V): 15.2 (R)

Redshift: 3.911

Distance: 23.6 Gly (7.2 Gpc) h⁻¹; _0.73; (co-moving); 12.05 Gly; (light travel time)