Hello, I'v been taking an interest to astronomical spectroscopy lately and I have some questions about that. In order to get myself going I wanted to get as much information about Sirius A and Sirius B using the distance, obtained by using parallax(I didn't do that but imagine I did) , and their visual spectra(nor did I obtain the spectra by myself, but again imagine that I did). If I used the information in the visual spectra to put in Wien's law, then the temperatures of the stars would be incorrect. Are there methods to get accurate information by using only the visual spectra, or does it only work for stars that have their lambda max in the visual spectra? Could I do something with the info in the visual spectra, i.e. an integral, and compare it to 'B-V color index', bolometric/apparent/absolute magnitude or something else? Thanks in advance, and I'm sorry if I´v understood astronomical spectrography completely wrong.