The Size Distribution for Jupiter-Family
Comets Nuclei and Other Related Asteroid
Populations
Colin Cowdrey
University of Kent
Can You Tell Which One is an Asteroid or a Comet?
Difficult isn’t it?
Direct ‘Snap-shot’ of nuclei for both populations may look similar causing difficulty when trying
to distinguish the two, therefore other parameter/properties are used in order to characterise
the objects in a given population. The aspects of these differences which are the source of
many investigations.
One property is the different regions of formation. During the early stages of the Solar
System formation; comets were formed just beyond the giant
planets whereas asteroid in the region between Mars and
Jupiter . Creating a variation in the composition of volatile materials which allow comparisons.
Thus , investigations regarding the difference in the variation of composition and the size
difference is currently at the forefront of this area.
The Not so Simple Solution
Many methods are applied in order to determine possible differences between the two populations. One technique which can be
implemented to establish any similarities/difference is known as the Cumulative Size Distribution (CSD), this is important for small
body populations as it constrains the formation.
The Investigation
Concentrated on an updated
Cumulative Size Distribution for
Jupiter-family comets and its
associated uncertainty.
Data Set
Problems Along the Way
Collaboration of all values of the
physical properties of JFC from
published papers.
Unfortunately cometary nuclei are extremely
difficult to detect and characterise, due to
the nuclei signal being faint and dominated
by the coma signal contribution.
The parameters considered
for the uncertainty of the
CSD will be the albedo, phase
function and the dimensions
of the given nucleus.
Resulting from the problematic detection of
JFC an incompleteness of the data occurs
creating deviation in results, thus
contributing to the overall uncertainty of the
CSD.
The updated value for the CSD slope of JFC would
improve the understanding of how comets relate
to asteroid populations, whether they are sources for certain asteroid families or contribute to the population once they are
depleted of volatile material.
Determine if there is a link between bodies that originate from the same region during formation. This would improve our
knowledge of how objects in the Solar System relate to one another and in general their roles in the formation of the Solar
System.
What is the Possible Impact on the Science Community?
Cost
Travel (per year)
Subsistence (per year)
University fees (per
year)
Equipment (onetime
payment)
Total
£500 conference travel fees
£10,000
£4000
£2000 personal computer
and software
£16,000
References
A. Alvarez-Candal and J. Licandro; The size distribution of asteroids in cometary orbits and related populations,
2006- Astronomy and Astrophysics
C. Snodgrass, A. Fitzsimmons, S. C. Lowry and P. Weissman; The size distribution of Jupiter Family comet nuclei;
2011-The Royal Astronomical Society
H.Rickman, J.Fernandez, B.Gustafson; Formation of Stable Dust Mantles on Short-Period Comet Nuclei, 1990Astronomy and Astrophysics
Jian-Yang Li, Marc J. Kuchner , Ronald J. Allen , Scott S. Sheppard; Measuring the sizes, shapes, surface features
and rotations of Solar System objects with interferometry, 2011-ICARUS
Philippe L. Lamy, Imre Toth, Yanga R. Fernández, Harold A. Weaver: Comets III: The Sizes, Shapes, Albedos, and
Colors of Cometary Nuclei: 2004: pg223-264