Skip to content
Home
About Us
Resources
Profiles Metrics
Authors Directory
Institutions Directory
Top Authors
Top Institutions
Top Sponsors
AI Digest
Contact Us
Menu
Home
About Us
Resources
Profiles Metrics
Authors Directory
Institutions Directory
Top Authors
Top Institutions
Top Sponsors
AI Digest
Contact Us
Home
About Us
Resources
Profiles Metrics
Authors Directory
Institutions Directory
Top Authors
Top Institutions
Top Sponsors
AI Digest
Contact Us
Menu
Home
About Us
Resources
Profiles Metrics
Authors Directory
Institutions Directory
Top Authors
Top Institutions
Top Sponsors
AI Digest
Contact Us
Publication Details
AFRICAN RESEARCH NEXUS
SHINING A SPOTLIGHT ON AFRICAN RESEARCH
earth and planetary sciences
High polarization degree of the continuum of comet 2P/Encke based on spectropolarimetric signals during its 2017 apparition
Astronomy and Astrophysics, Volume 620, Article A161, Year 2018
Notification
URL copied to clipboard!
Description
Context. Spectropolarimetry is a powerful technique for investigating the physical properties of gas and solid materials in cometary comae without mutual contamination, but only a few spectropolarimetric studies have been conducted to extract each component. Aims. We attempt to derive the continuum (i.e., scattered light from dust coma) polarization degree of comet 2P/Encke, free of the influence of molecular emissions. The target is unique in that its orbit is dynamically decoupled from Jupiter, like the main-belt asteroids, but it ejects gas and dust like ordinary comets. Methods. We observed the comet using the Hiroshima Optical and Near-Infrared Camera attached to the Cassegrain focus of the 150 cm Kanata telescope on UT 2017 February 21 when the comet was at the solar phase angle of α = 75°.7. Results. We find that the continuum polarization degree with respect to the scattering plane is P cont, r = 33.8 ± 2.7% at the effective wavelength of 0.82 μm, which is significantly higher than those of cometary dust in a high-P max group at similar phase angles. Assuming that an ensemble polarimetric response of the dust of 2P/Encke as a function of phase angle is morphologically similar with those of other comets, its maximum polarization degree is estimated to P max â40% at α max â 100°. In addition, we obtain the polarization degrees of the C 2 swan bands (0.51-0.56 μm), the NH 2 α bands (0.62-0.69 μm), and the CN-red system (0.78-0.94 μm) in a range of 3-19%, which depend on the molecular species and rotational quantum numbers of each branch. The polarization vector is aligned nearly perpendicularly to the scattering plane with an average of 0°.4 over a wavelength range of 0.50-0.97 μm. Conclusions. From the observational evidence, we conjecture that the high polarization degree of 2P/Encke might be attributable to a dominance of large dust particles around the nucleus, which have remained after frequent perihelion passages near the Sun. © ESO 2018.
Authors & Co-Authors
Shinnaka, Yoshiharu
Japan, Kyoto
Kyoto Sangyo University
Japan, Mitaka
National Institutes of Natural Sciences - National Astronomical Observatory of Japan
Nakaoka, Tatsuya
Japan, Higashihiroshima
Hiroshima University
Kuroda, Daisuke
Japan, Kyoto
Kyoto University
Hanayama, Hidekazu
Japan, Mitaka
National Institutes of Natural Sciences - National Astronomical Observatory of Japan
Takahashi, Jun
Japan, Kobe
University of Hyogo
Baar, Stefan
Japan, Kobe
University of Hyogo
Saito, Tomoki
Japan, Kobe
University of Hyogo
Kawabata, Miho
Japan, Higashihiroshima
Hiroshima University
Uemura, Makoto
Japan, Higashihiroshima
Hiroshima University
Morokuma, Tomoki
Japan, Tokyo
The University of Tokyo
Murata, Katsuhiro L.
Japan, Tokyo
Tokyo Institute of Technology
Takagi, Seiko
Japan, Sapporo
Hokkaido University
Morihana, Kumiko
Japan, Nagoya
Nagoya University
Nagayama, Takahiro
Japan, Kagoshima
Kagoshima University
Sekiguchi, Kazuhiro
Japan, Mitaka
National Institutes of Natural Sciences - National Astronomical Observatory of Japan
Kawabata, Koji S.
Japan, Higashihiroshima
Hiroshima University
Akitaya, Hiroshi
Japan, Higashihiroshima
Hiroshima University
Japan, Saitama
Saitama University
Statistics
Citations: 7
Authors: 17
Affiliations: 12
Identifiers
Doi:
10.1051/0004-6361/201833968
ISSN:
00046361