first_spec_class second_spec_class prob_first_spec_class prob_second_spec_class taxonomy wavelength author ref method C Bus VIS Binzel 2019Icar..324...41B SPEC C Bus VIS Bus 2002Icar..158..146B SPEC C B 0.840000 0.120000 Mahlke VIS Mahlke 2022A&A...665A..26M SPEC