  We present a visible multi-band photometry of trans-Neptunian objects (TNOs)
observed by the Subaru Telescope in the framework of Hyper Suprime-Cam Subaru
Strategic Program (HSC-SSP) from March in 2014 to September in 2016. We
measured the five broad-band (g, r, i, z, and Y) colors over the wavelength
range from 0.4 um to 1.0 um for 30 known TNOs using the HSC-SSP survey data
covering ~500 deg2 of sky within +/-30 deg of ecliptic latitude. This dataset
allows us to characterize the dynamical classes based on visible reflectance
spectra as well as to examine the relationship between colors and the other
parameters such as orbital elements. Our results show that the hot classical
and scattered populations share similar color distributions, while the cold
classical population has a reflective decrease toward shorter wavelength below
the i band. Based on the obtained color properties, we found that the TNO
sample examined in the present work can be separated into two groups by
inclination (I), the low-I population consisting of cold classical objects and
high-I population consisting of hot classical and scattered objects. The whole
sample exhibits an anti-correlation between colors and inclination, but no
significant correlation between colors and semi-major axis, perihelion
distance, eccentricity, or absolute magnitude. The color-inclination
correlation does not seem to be continuous over the entire inclination range.
Rather, it is seen only in the high-I population. We found that the low- and
high-I populations are distinguishable in the g-i vs. eccentricity plot, but
four high-I objects show g-i colors similar to those of the low-I population.
If we exclude these four objects, the high-I objects show a positive
correlation between g-i and eccentricity and a negative correlation between g-i
and inclination with high significance levels.
