Editing 5145 Pholus (section)

=== Spectral type and color ===
After its discovery, Pholus was quickly found to be very red in color. The color has been speculated to be due to organic compounds on its surface.<ref name="Wilson-1994" /> It is classified as a Z-class object on the [[Tholen classification|Tholen]] taxonomic scheme.<ref name="jpldata" />

The object has been classified by astronomers as [[Trans-Neptunian object#Colours|RR]] and [[Trans-Neptunian object#Colours|RR-U]] type, respectively.<ref name="Perna-2010" /><ref name="Belskaya-2015" /> Polarimetric observations with ESO's [[Very Large Telescope]] in 2007 and 2008, revealed noticeable negative polarization at certain phase angles, distinctly different from that of trans-Neptunian objects. Pholus appears to have a rather homogeneous surface with a small amount of water frost on its darker regions.<ref name="Belskaya-2015" />

The surface composition of Pholus has been estimated from its reflectance spectrum using two spatially segregated components:<ref name="Cruikshank-1998" /> dark [[amorphous carbon]] and an intimate mixture of [[water]] ice, [[methanol]] ice, [[olivine]] grains, and complex organic compounds ([[tholin]]s). The [[carbon black]] component was used to match the low [[albedo]] of the object. Unlike [[2060 Chiron|Chiron]], Pholus has shown no signs of [[comet]]ary activity.