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| Titel |
Polarimetry of the dwarf planet (136472) Makemake |
| VerfasserIn |
A. Stinson, I. Belskaya, S. Bagnulo, G. P. Tozzi, K. Muinonen, A. Barucci, S. Fornasier |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250063762
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| Zusammenfassung |
| We present the first polarimetric observations of one of the largest transneptunian
objects: (136472) Makemake. The linear polarization of Makemake was measured in
April-May 2011 in the Bessel R filter with the FOSR2 instrument of the ESO VLT.
In the phase-angle range 0.6-1.1 deg, we measured a small amount of negative
polarization (about -0.3%), nearly constant within the accuracy of our measurements
(0.05-0.1%).
Our new data confirms the existence of two distinct types of polarimetric behaviours
found for large and small transneptunian objects [1]. The polarization phase curve behavior
of the Makemake is similar to that of other large TNO’s, which all show a small polarization
in the scattering plane slowly changing in the observed phase angle range. The amount of
polarization measured for Makemake is more similar to that measured in Eris than in Pluto
when we consider the values obtained at the same phase angles. The polarization of
Makemake’s surface at 1 deg of phase angle is the smallest one (in absolute term) if
compared to any other icy Solar system bodies measured so far. It gives additional evidence
in favour of the particular surface properties of the Makemake found from thermal
modeling [2]. In this poster we will discuss the constraints on the surface characteristics
of Makemake set by our new measurements combined with previously available
data.
[1] Bagnulo, S., Belskaya, I., Muinonen, K., Tozzi, G.P., Barucci, M. A., Kolokolova, L.,
Fornasier, S., Discovery of two distinct polarimetric behaviours of transneptunian objects.
Astron. Astroph. 491, L33, 2008.
[2] Lim, T. L., Stansberry, J., Muller, T.G., et al.: A survey of the trans-Neptunian region.
III. Thermophysical properties of 90482 Orcus and 136472 Makemake. Astron. Astroph. 518,
L148, 2010. |
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