Enhanced Activity in (2060) Chiron

ATel #14903; Matthew Dobson (QUB) , Alan Fitzsimmons (QUB), Megan E. Schwamb (QUB), Michael S. P. Kelley (U. Maryland), Tim Lister (Las Cumbres Observatory), Larry Denneau (IfA, University of Hawaii), Aren Heinze (University of Washington), L. Shingles (QUB), Ken W. Smith (QUB) , John Tonry (IfA, University of Hawaii), Henry Weiland (IfA, University of Hawaii), David R. Young (QUB), Susan Benecchi (PSI), Anne Verbiscer (UVa) on behalf of the ATLAS Survey and the LCO Outbursting Objects Key (LOOK) Project
on 8 Sep 2021; 08:12 UT
Distributed as an Instant Email Notice Comets
Credential Certification: Megan E. Schwamb (m.schwamb@qub.ac.uk)

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We report a photometric brightening of Centaur (2060) Chiron via monitoring with the Asteroid-Terrestrial impact Last Alert System (ATLAS) during normal survey operations. o-band photometry during 18 June to 29 August 2021 UTC gives a median phase-corrected absolute magnitude of H(o)=5.05+/-0.08, 0.38 magnitudes brighter than measured throughout the 2016-2020 apparitions. The measured PSF (point-spread-function) FWHM is 1.8 arcsec, consistent with field stars. Co-addition of 20x30 second exposures from 08 August to 29 August shows a possible marginal extension to the PSF of approximately 9" from the centre of Chiron at PA 250 degrees. 4 w-band images were taken on 2021 06 September UTC by a Las Cumbres Observatory (LCO) 1-m telescope at Cerro Tololo Interamerican Observatory (CTIO). Each 245 seceond image was tracked nonsidereally at the rate of the Centaur (where the stars were trailed by 0.4" per exposure). In these deeper exposures, we find no significant extension in PSF or visible coma/tail features.

The Asteroid Terrestrial-impact Last Alert System (ATLAS) project is primarily funded to search for Near Earth Asteroids through NASA grants NN12AR55G, 80NSSC18K0284, and 80NSSC18K1575; byproducts of the NEO search include images and catalogs from the survey area. This work was partially funded by Kepler/K2 grant J1944/80NSSC19K0112 and HST GO-15889, and STFC grants ST/T000198/1 and ST/S006109/1. The ATLAS science products have been made possible through the contributions of the University of Hawaii Institute for Astronomy, the Queen's University Belfast, the Space Telescope Science Institute, the South African Astronomical Observatory, and The Millennium Institute of Astrophysics (MAS), Chile.

This work makes use of observations from the Las Cumbres Observatory global telescope network.