1,2,7,9,10,- 1School of Physical and Chemical Sciences – Te Kura Matü, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealan
- 2Space Science and Technology Centre, School of Earth and Planetary Sciences, Curtin University, Perth, Western Australia 6845,7 Australia
- 3Institute for Astronomy, University of Edinburgh, Royal Observatory, Edinburgh EH9 3HJ, UK
- 4Physics Department, United States Naval Academy, 572C Holloway Rd, Annapolis, MD 21402, USA10
- 5University of Maryland, Department of Astronomy, College Park, MD 20742, USA11
- 6Department of Physics and Astronomy, Michigan State University, East Lansing, 48824, MI, USA12
- 7Astrophysics Research Centre, School of Mathematics and Physics, Queen’s University Belfast, Belfast BT7 1NN, United Kingdom
- 8Laboratoire de Géologie de Lyon, LGL-TPE, UMR 5276 CNRS / Université de Lyon / Université Claude Bernard Lyon 1 / ENS Lyon,14 69622 Villeurbanne, France
- 9STAR Institute, Université de Liège, Allée du 6 aout, 19C, 4000 Liège, Belgium
- 10Aix Marseille Univ, CNRS, LAM, Laboratoire d’Astrophysique de Marseille, Marseille, France
- 11European Southern Observatory, Alonso de Cordova 3107, Santiago, Chile
- 12School of Applied and Engineering Physics, Mohammed VI Polytechnic University, Ben Guerir 43150, Morocco
- 13Université Marie et Louis Pasteur, CNRS, Institut UTINAM (UMR 6213), OSU THETA, F-25000 Besan¸con, Franc
- 14Instituto de Estudios Astrofisicos, Facultad de Ingenieria y Ciencias, Universidad Diego Portales, Av. Ejercito Libertador 441,21 Santiago, 8370191, Chile
The interstellar comet 2I/Borisov is the first interstellar object where compositional characterisation was possible throughout its entire perihelion passage. We report all 16 epochs of a comprehensive optical observation campaign with ESO VLT’s integral field spectrograph MUSE, spanning 126 days from 2019 November 14 to 2020 March 19. The spatial dust emission of 2I/Borisov was predominantly smooth, with no seasonal effect. A jet-like feature was consistently visible. The gas production morphology of its coma is also smooth and similar for C2, NH2, and CN: symmetric around the photocentre. The production rates of these species gently declined into and beyond perihelion, until 2I’s outburst and splitting event in early 2020 March. NH2 then significantly spiked, with a only moderate rise in C2 and CN; the dust emission also slightly reddened. 2I/Borisov is a carbon-depleted, very NH2-rich comet relative to those yet measured in the Solar System.
How to cite: Deam, S., Bannister, M., Opitom, C., Knight, M. M., Ridden-Harper, R., Seligman, D. Z., Fitzimmons, A., Guilbert-Lepoutre, A., Jehin, E., Jorda, L., Marsset, M., Moulane, Y., Rousselot, P., Vernazza, P., and Yang, B.: A portrait throughout perihelion of the NH2-rich interstellar comet 2I/Borisov, EPSC-DPS Joint Meeting 2025, Helsinki, Finland, 7–12 Sep 2025, EPSC-DPS2025-1348, https://doi.org/10.5194/epsc-dps2025-1348, 2025.
