https://www.universetoday.com/148082/astronomers-find-a-new-binary-object-in-the-kuiper-belt/#more-148082 Pan-STARRS1 discovered the binary object in 2011. The binary object has the name “523764 2014 WC510,” or simply 2014 WC510. During the observed occultation, it was 30.5 au from the Sun and 29.6 au from Earth, with an apparent magnitude of V = 22.1. For comparison, Neptune’s apparent magnitude is 7.78. The primary object in the pair has a diameter of D = 181 ± 16 km, and the secondary object has a diameter of D = 138 ± 32 km.
“To date,” the authors write in their paper, “only 14 TNOs or their satellites (excluding Pluto) have an accurate size and albedo published from stellar occultations.”
觀星論壇 
