The Cliff (cosmological object)
The Cliff (RUBIES-UDS-154183) is a compact, distant extragalactic object in the constellation Cetus. It appears as a small red dot and shows an unusually strong Balmer jump in its spectrum. Its position is RA 02h 17m 38.58s, Dec −05° 07′ 46.79″ (epoch J2000), and its redshift is 3.548, indicating it is very far away.
It was discovered in 2024 by the James Webb Space Telescope as part of the RUBIES survey in the Ultra Deep Survey (UDS). The data include photometry from the NIRCam and MIRI instruments (the orange points on the chart indicate these measurements).
Spectroscopic analysis suggests it could be a black hole star, a rare type of object where a star is influenced by a nearby black hole. However, this idea is not certain and more observations are needed.
This page was last edited on 3 February 2026, at 06:33 (CET).