The perihelion activity of comet 67P/Churyumov-Gerasimenko as seen by robotic telescopes

Colin Snodgrass (1) , Cyrielle Opitom (2) , Miguel de Val-Borro (3, 4) , Emmanuel Jehin (2) , Jean Manfroid (2) , Tim Lister (5) , Jon Marchant (6) , Geraint H. Jones (7, 8) , Alan Fitzsimmons (9) , Iain A. Steele (6) , Robert J. Smith (6) , Helen Jermak (10, 6) , Thomas Granzer (11) , Karen J. Meech (12) , Philippe Rousselot (13) , Anny Chantal Levasseur-Regourd (14)

1 School of Physical Sciences [Milton Keynes]
2 Institut d'Astrophysique et de Géophysique [Liège]
3 Department of Astrophysical Sciences [Princeton]
4 Astrochemistry Laboratory [Greenbelt]
5 LCO - Las Cumbres Observatory
6 ARI - Astrophysics Research Institute [Liverpool]
7 MSSL - Mullard Space Science Laboratory
8 CPS - Centre for Planetary Sciences [UCL/Birkbeck]
9 ARC - Astrophysics Research Centre [Belfast]
10 Department of Physics [Lancaster]
11 AIP - Leibniz-Institut für Astrophysik Potsdam
12 Institute for Astronomy [Honolulu]
13 UTINAM - Univers, Transport, Interfaces, Nanostructures, Atmosphère et environnement, Molécules (UMR 6213)
14 PLANETO - LATMOS

Around the time of its perihelion passage the observability of 67P/Churyumov-Gerasimenko from Earth was limited to very short windows each morning from any given site, due to the low solar elongation of the comet. The peak in the comet's activity was therefore difficult to observe with conventionally scheduled telescopes, but was possible where service/queue scheduled mode was possible, and with robotic telescopes. We describe the robotic observations that allowed us to measure the total activity of the comet around perihelion, via photometry (dust) and spectroscopy (gas), and compare these results with the measurements at this time by Rosetta's instruments. The peak of activity occurred approximately two weeks after perihelion. The total brightness (dust) largely followed the predictions from Snodgrass et al. (2013), with no significant change in total activity levels from previous apparitions. The CN gas production rate matched previous orbits near perihelion, but appeared to be relatively low later in the year.

Keywords: 67P/Churyumov-Gerasimenko; Comets

Domains: Earth and Planetary Astrophysics [astro-ph.EP]

Colin Snodgrass, Cyrielle Opitom, Miguel de Val-Borro, Emmanuel Jehin, Jean Manfroid, et al.. The perihelion activity of comet 67P/Churyumov-Gerasimenko as seen by robotic telescopes. Monthly Notices of the Royal Astronomical Society, 2016, 462 (Suppl. 1), pp.S138-S145. ⟨10.1093/mnras/stw2300⟩. ⟨insu-01367573⟩