Photometry and high-resolution spectroscopy of comet 21P/Giacobini-Zinner during its 2018 apparition

Abstract

We report on photometry and high resolution spectroscopy of the chemically peculiar Jupiter-family Comet (hereafter JFC) 21P/Giacobini-Zinner. Comet 21P is a well known member of the carbon-chain depleted family but displays also a depletion of amines. We monitored continuously the comet over more than seven months with the two TRAPPIST telescopes (TN and TS), covering a large heliocentric distance range from 1.60 au inbound to 2.10 au outbound with a perihelion at 1.01 au on September 10, 2018. We computed and followed the evolution of the dust (represented by Af$\rho$) and gas production rates of the daughter species OH, NH, CN, C${}_3$, and C${}_2$ and their relative abundances to OH and to CN over the comet orbit. We compared them to those measured in the previous apparitions. The activity of the comet and its water production rate reached a maximum of (3.72$\pm$0.07)$\times$10${}^{28}$ molec/s on August 17, 2018 (r${}_h$=1.07 au), 24 days before perihelion. The peak value of A(0)f$\rho$ was reached on the same date (1646$\pm$13) cm in the red filter. The abundance ratios of the various species are remarkably constant over a large range of heliocentric distances, before and after perihelion, showing a high level of homogeneity of the ices in the surface of the nucleus. The behaviour and level of the activity of the comet is also remarkably similar over the last five orbits. About the coma dust colour, 21P shows reflectively gradients similar to JFCs. We obtained a high resolution spectrum of 21P with UVES at ESO VLT one week after perihelion. Using the CN B-X (0,0) violet band, we measured ${}^{12}$C/${}^{13}$C and ${}^{14}$N/${}^{15}$N isotopic ratios of 100$\pm$10 and 145$\pm$10, respectively, both in very good agreement with what is usually found in comets.

arXiv comment14 pages, 11 figures, Accepted for publication in A&A

References in corpus (27)

• Cometary Chemistry and the Origin of Icy Solar System Bodies, the view after Rosetta
• Color Systematics of Comets and Related Bodies
• Large excess of heavy nitrogen in both hydrogen cyanide and cyanogen from comet 17P/Holmes
• The CN isotopic ratios in comets
• Thirty Years of Cometary Spectroscopy from McDonald Observatory
• Terrestrial deuterium-to-hydrogen ratio in water in hyperactive comets
• Ensemble Properties of Comets in the Sloan Digital Sky Survey
• The Peculiar Volatile Composition of CO-Dominated Comet C/2016 R2 (PanSTARRS)
• A Survey of Water Production in 61 Comets from SOHO/SWAN Observations of Hydrogen Lyman-alpha: Twenty-One Years 1996-2016
• The Evolving Activity of the Dynamically Young Comet C/2009 P1 (Garradd)
• Comet 22P/Kopff: Dust environment and grain ejection anisotropy from visible and infrared observations
• Water Production by Comet 103P/Hartley 2 Observed with the SWAN Instrument on the SOHO Spacecraft
• Ground-based Optical and SPITZER Infrared Imaging Observations of Comet 21P/Giacobini-Zinner
• Monitoring of the activity and composition of comets 41P/Tuttle-Giacobini-Kresak and 45P/Honda-Mrkos-Pajdusakova
• Evidence for depletion of heavy silicon isotopes at comet 67P/Churyumov-Gerasimenko
• The splitting of double-component active asteroid P/2016 J1 (PANSTARRS)
• Meteor Shower Modeling: Past and Future Draconid Outbursts
• Dust loss from activated asteroid P/2015 X6
• Early evolution of disrupted asteroid P/2016 G1 (PANSTARRS)
• TRAPPIST photometry and imaging monitoring of comet C/2013 R1(Lovejoy): Implications for the origin of daughter species
• On the dust environment of Main-Belt Comet 313P/Gibbs
• Evolution of H${}_2$O Production in Comet C/2012 S1 (ISON) as Inferred from Forbidden Oxygen and OH Emission
• Dust Production of Comet 21P/Giacobini-Zinner Throughout its 2018 Apparition
• Dust modelling and a dynamical study of comet 41P/Tuttle-Giacobini-Kresak during its 2017 perihelion passage
• High-resolution optical spectroscopic observations of comet 21P/Giacobini-Zinner in Its 2018 apparition
• Isotopic ratios in outbursting comet C/2015 ER61
• Comet 66P/du Toit: not a near Earth main belt comet

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