first_spec_class second_spec_class prob_first_spec_class prob_second_spec_class taxonomy wavelength author ref method D Bus VIS Luo 2024AJ....167...13L SPEC D Bus VIS Luo 2024AJ....167...13L SPEC L L 0.3218 0.0170 Bus-Demeo VIS Sergeyev 2021A&A...652A..59S PHOT