Apparent Outburst of Comet C/2014 UN271 (Bernardinelli-Bernstein)
ATel #14917; Michael S. P. Kelley (U. Maryland), Tim Lister (Las Cumbres Observatory), Carrie E. Holt (U. Maryland), on behalf of the LCO Outbursting Objects Key Project
on 14 Sep 2021; 17:46 UT
Credential Certification: Tim Lister (tlister@lco.global)
We report an apparent outburst of comet C/2014 UN271 (Bernardinelli-Bernstein), as seen in Las Cumbres Observatory 1-m telescope data. Following our initial observations (Kokotanekova et al. 2021, ATEL #14733), the comet had faded in brightness to r=19.57+/-0.04 mag, measured within a 4" radius aperture on 2021 Sep 09.103 UTC and calibrated to the PS1 magnitude system. In our next data taken 2021 Sep 09.924 UTC the comet had brightened to r=18.92+/-0.04 mag, a difference of -0.65+/-0.06 mag. No background source is visible at the comet's coordinates in Digitized Sky Survey images. The brightening is confirmed in subsequent data taken 2021 Sep 11.335 UTC, r=19.02+/-0.04 mag. On Sep 09, the comet was 19.89 au from the Sun, 19.44 au from the Earth, and at a phase angle of 2.6 deg.
This work makes use of observations from the Las Cumbres Observatory global telescope network.
