Rotating dust particles in the coma of comet 67P/Churyumov-Gerasimenko

M. Fulle (1) , S. L. Ivanovski (2) , I. Bertini (3) , P. Gutierrez (4) , L. Lara (4) , H. Sierks (5) , V. Zakharov (6) , V. Della Corte (2) , A. Rotundi (7, 2) , C. Barbieri (8) , P. L. Lamy (9) , R. Rodrigo (10, 11) , D. Koschny (12) , H. Rickman (13, 14) , H. U. Keller (15) , J. Agarwal (5) , Michael F. A'Hearn (16) , M.A. Barucci (6) , Jean-Loup Bertaux (17) , Dennis Bodewits (16) , Gabriele Cremonese (18) , V. da Deppo (19) , B. Davidsson (14) , S. Debei (20) , M. de Cecco (21) , S. Fornasier (6) , O. Groussin (9) , C. Güttler (5) , S. F. Hviid (22) , W. Ip (23) , L. Jorda (9) , J. Knollenberg (22) , R. Kramm (5) , Ekkehard Kührt (22) , M. Küppers (24) , M. Lazzarin (8) , J. J. Lopez-Moreno (4) , F. Marzari (8) , H. Michalik (25) , G. Naletto (3, 20, 19) , N. Oklay (5) , L. Sabau (26) , Nicolas Thomas (27) , C. Tubiana (5) , J.-B. Vincent (5) , K.-P. Wenzel (12)

1 OAT - INAF - Osservatorio Astronomico di Trieste
2 IAPS - Istituto di Astrofisica e Planetologia Spaziali - INAF
3 CISAS - Centro di Ateneo di Studi e Attività Spaziali “Giuseppe Colombo”
4 IAA - Instituto de Astrofísica de Andalucía
5 MPS - Max-Planck-Institut für Sonnensystemforschung
6 LESIA - Laboratoire d'études spatiales et d'instrumentation en astrophysique
7 PARTHENOPE - Università degli Studi di Napoli “Parthenope” = University of Naples
8 Dipartimento di Fisica e Astronomia "Galileo Galilei"
9 LAM - Laboratoire d'Astrophysique de Marseille
10 CAB - Centro de Astrobiologia [Madrid]
11 ISSI - International Space Science Institute [Bern]
12 RSSD - Research and Scientific Support Department, ESTEC
13 CBK - Space Research Centre of Polish Academy of Sciences
14 Department of Physics and Astronomy [Uppsala]
15 IGEP - Institut für Geophysik und Extraterrestrische Physik [Braunschweig]
16 Department of Astronomy [College Park]
17 PLANETO - LATMOS
18 OAPD - INAF - Osservatorio Astronomico di Padova
19 IFN - CNR Institute for Photonics and Nanotechnologies
20 Department of Industrial Engineering [Padova]
21 University of Trento [Trento]
22 DLR Institut für Planetenforschung
23 IANCU - Institute of Astronomy [Taiwan]
24 Operations Department (ESAC)
25 Institut für Datentechnik und Kommunikationsnetze
26 INTA - Instituto Nacional de Técnica Aeroespacial
27 Physikalisches Institut [Bern]

During September and October 2014, the OSIRIS cameras onboard the ESA Rosetta mission detected millions of single particles. Many of these dust particles appear as long tracks (due to both the dust proper motion and the spacecraft motion during the exposure time) with a clear brightness periodicity. Aims. We interpret the observed periodic features as a rotational and translational motion of aspherical dust grains. Methods. By counting the peaks of each track, we obtained statistics of a rotation frequency. We compared these results with the rotational frequency predicted by a model of aspherical dust grain dynamics in a model gas flow. By testing many possible sets of physical conditions and grain characteristics, we constrained the rotational properties of dust grains. Results. We analyzed on the motion of rotating aspherical dust grains with different cross sections in flow conditions corresponding to the coma of 67P/Churyumov-Gerasimenko qualitatively and quantitatively. Based on the OSIRIS observations, we constrain the possible physical parameters of the grains.

Keywords: Space vehicles; Numerical methods; Comets; 67P/Churyumov-Gerasimenko

Domains: Atmospheric and Oceanic Physics [physics.ao-ph]; Physics [physics]; Astrophysics [astro-ph]

M. Fulle, S. L. Ivanovski, I. Bertini, P. Gutierrez, L. Lara, et al.. Rotating dust particles in the coma of comet 67P/Churyumov-Gerasimenko. Astronomy and Astrophysics - A&A, 2015, 583, A14 (8 p.). ⟨10.1051/0004-6361/201526158⟩. ⟨insu-01202381⟩