TY - CONF
T1 - The Distribution of Geometric Albedos of Jupiter-Family Comets From SEPPCoN and Visible-Wavelength Photometry
AU - Fernandez, Yanga R.
AU - Weaver, Harold A.
AU - Lisse, Casey M.
AU - Meech, Karen Jean
AU - Lowry, Stephen C.
AU - Bauer, James M.
AU - Fitzsimmons, Alan
AU - Snodgrass, Colin
PY - 2016/1/1
Y1 - 2016/1/1
N2 - Cometary nuclei are some of the least reflective natural objects in the
Solar System, although the number of comets for which the reflectivity
has heretofore actually been measured is small due to the difficulty of
the requisite measurements. When no other information is present, it is
common to assume a geometric albedo of 4%, and this is consistent with
the limited number of known albedos. However the true average albedo,
median albedo, and spread of the distribution are not well constrained.
Knowing the ensemble properties of cometary albedos would aid in
understanding the surface scattering properties as well as the interior
thermal evolution and surface evolution of the population. We present
here a preliminary estimate of the distribution of geometric albedos
among the Jupiter-family comet (JFC) population. We make use of and
build on the results of the Survey of Ensemble Physical Properties of
Cometary Nuclei (SEPPCoN), in which we obtained new and independent
estimates of the radii of 89 JFCs [1,2]. We will present our preliminary
albedo estimates for ~50 JFC nuclei (by far the most ever obtained), and
we will discuss the implications of the ensemble of the results. These
JFCs were all observed in R-band, and were all observed at relatively
large heliocentric distances (usually >4 AU from the Sun) where the
comets appeared inactive, thus minimizing coma contamination. We
acknowledge the support of NASA grant NNX09AB44G, of NSF grant
AST-0808004, and of the Astrophysical Research Consortium/Apache Point
Observatory for this work. References: [1] Y. R. Fernandez et al., 2013,
Icarus 226, 1138. [2] M. S. Kelley et al., 2013, Icarus 225, 475.
AB - Cometary nuclei are some of the least reflective natural objects in the
Solar System, although the number of comets for which the reflectivity
has heretofore actually been measured is small due to the difficulty of
the requisite measurements. When no other information is present, it is
common to assume a geometric albedo of 4%, and this is consistent with
the limited number of known albedos. However the true average albedo,
median albedo, and spread of the distribution are not well constrained.
Knowing the ensemble properties of cometary albedos would aid in
understanding the surface scattering properties as well as the interior
thermal evolution and surface evolution of the population. We present
here a preliminary estimate of the distribution of geometric albedos
among the Jupiter-family comet (JFC) population. We make use of and
build on the results of the Survey of Ensemble Physical Properties of
Cometary Nuclei (SEPPCoN), in which we obtained new and independent
estimates of the radii of 89 JFCs [1,2]. We will present our preliminary
albedo estimates for ~50 JFC nuclei (by far the most ever obtained), and
we will discuss the implications of the ensemble of the results. These
JFCs were all observed in R-band, and were all observed at relatively
large heliocentric distances (usually >4 AU from the Sun) where the
comets appeared inactive, thus minimizing coma contamination. We
acknowledge the support of NASA grant NNX09AB44G, of NSF grant
AST-0808004, and of the Astrophysical Research Consortium/Apache Point
Observatory for this work. References: [1] Y. R. Fernandez et al., 2013,
Icarus 226, 1138. [2] M. S. Kelley et al., 2013, Icarus 225, 475.
M3 - Abstract
ER -