Size and albedo of the largest detected Oort-cloud object
(arxiv.org)
The recently announced Oort-cloud comet C/2014 UN271 (Bernardinelli-Bernstein) is remarkable in at least three respects: (i) it was discovered inbound as far as ~29 au from the Sun (with prediscovery images up to ~34 au); (ii) it showed cometary activity already at almost 24 au; and (iii) its nuclear magnitude (Hr ~ 8.0) indicates an exceptionally large object.
The recently announced Oort-cloud comet C/2014 UN271 (Bernardinelli-Bernstein) is remarkable in at least three respects: (i) it was discovered inbound as far as ~29 au from the Sun (with prediscovery images up to ~34 au); (ii) it showed cometary activity already at almost 24 au; and (iii) its nuclear magnitude (Hr ~ 8.0) indicates an exceptionally large object.