Detection and Monitoring of Fragments of Comet C/2023 R1 (PANSTARRS)
ATel #17915; Nick James (British Astronomical Association), Helen Usher (Open University, British Astronomical Association, Cardiff University), Veronika Parakonna (The Coopers Company and Coborn School, Upminster), David Benjamin (The Coopers Company and Coborn School, Upminster), Arthur Dragomir (Concord College, Shrewsbury), Amelia Davies (The Coopers Company and Coborn School, Upminster), Michael S. P. Kelley (Univ. Maryland), on behalf of the Comet Chasers Project and the British Astronomical Associationâs Work Experience Project
on 20 Jul 2026; 19:17 UT
Credential Certification: Tim Lister (tlister@lco.global)
On 2026 July 10 J-F Soulier reported on comets-ml (message#35503) a possible condensation in the tail of C/2023 R1 based on images taken on July 9.91 UTC. This was confirmed in images obtained by M. Mobberley and P. Carson on July 13. An analysis, by N. James, of the observations by M. Mobberley showed a fragment (C/2023 R1-b) around 10 arcsec behind the main component and around magnitude 18. Subsequent examination of images in the BAA archive here: https://britastro.org/cometobs/2023r1/thumbnails.html showed that the condensation was visible on an image from E. Bryssinck obtained on July 8.91.
We report the result of analysis by N. James of further observations made by students, who are part of the BAA work experience project, using the 2.0m LCOGT Faulkes Telescope North (MPC F65) telescope on Haleakala and Faulkes Telescope South (MPC E10) at Siding Spring. Observations were made on 2026 July 15, 16, 18 and 19 by V. Parakonna, D Benjamin, A Dragomir and A Davies (respectively). The new observations showed a very faint second condensation 2 arcseconds east of the b component which we have designated C/2023 R1-c.
Astrometry of the b component relative to the main comet photocentre using these images on four nights showed a best-fit linear separation rate of 0.18 arcsec/day.
Date (UTC) dRA (â) dDec (â) Station
2026-07-15T06:32:27 11.08 1.84 F65
2026-07-15T06:34:43 11.01 1.91 F65
2026-07-15T06:36:55 11.01 1.94 F65
2026-07-16T07:00:53 11.18 1.94 F65
2026-07-16T07:01:59 11.21 2.05 F65
2026-07-16T07:03:05 11.21 1.98 F65
2026-07-18T07:34:29 11.67 1.91 F65
2026-07-18T07:49:43 11.52 1.91 F65
2026-07-19T08:46:48 11.73 1.84 E10
2026-07-19T08:53:24 11.73 2.05 E10
Supporting images and plots are available from the BAA Comet Section website here:
https://britastro.org/section_news_item/c-2023-r1-panstarrs-fragmentation
The BAA Work Experience Project students will continue to monitor developments with the comet, looking for further fragmentation. We encourage others to also make further observations and submit them to the BAA Comet Archive https://britastro.org/cometobs/2023r1/thumbnails.html
This work makes use of observations from the Las Cumbres Observatory global telescope network.
The BAA Work Experience Project accesses telescopes through the Comet Chasers education and outreach project. The Comet Chasers project https://www.cometchasers.org/), led by Helen Usher, is funded by the UK Science and Technology Facilities Council (via the DeepSpace2DeepImpact Project), the Open University and Cardiff University. It accesses the LCOGT telescopes through the Schools Observatory/Faulkes Telescope Project (TSO2026A-020 The Schools' Observatory/Dill Faulkes Education Trust), which is partly funded by the Dill Faulkes Educational Trust, and through the LCO Global Sky Partners Programme (LCOEPO2023B-013).
The contact point for the BAA Comet Section is Nick James (ndj@nickdjames.com) and for the BAA Work Experience Project is Helen Usher (helen.usher@open.ac.uk).
BAA Comet Archive https://britastro.org/cometobs/2023r1/thumbnails.html
Comets Mailing List [2026 July 10] https://groups.io/g/comets-ml
Supporting images and plots are available from the BAA Comet Section website
