English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We report on photometry and high resolution spectroscopy of the chemicallypeculiar Jupiter-family Comet (hereafter JFC) 21P/Giacobini-Zinner. Comet 21Pis a well known member of the carbon-chain depleted family but displays also adepletion of amines. We monitored continuously the comet over more than sevenmonths with the two TRAPPIST telescopes (TN and TS), covering a largeheliocentric distance range from 1.60 au inbound to 2.10 au outbound with aperihelion at 1.01 au on September 10, 2018. We computed and followed theevolution of the dust (represented by Af$\rho$) and gas production rates of thedaughter species OH, NH, CN, C$_3$, and C$_2$ and their relative abundances toOH and to CN over the comet orbit. We compared them to those measured in theprevious apparitions. The activity of the comet and its water production ratereached 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$13) cm in the red filter. The abundanceratios of the various species are remarkably constant over a large range ofheliocentric distances, before and after perihelion, showing a high level ofhomogeneity of the ices in the surface of the nucleus. The behaviour and levelof the activity of the comet is also remarkably similar over the last fiveorbits. About the coma dust colour, 21P shows reflectively gradients similar toJFCs. We obtained a high resolution spectrum of 21P with UVES at ESO VLT oneweek after perihelion. Using the CN B-X (0,0) violet band, we measured$^{12}$C/$^{13}$C and $^{14}$N/$^{15}$N isotopic ratios of 100$\pm$10 and145$\pm$10, respectively, both in very good agreement with what is usuallyfound in comets.

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