Maximum wavelength of M101 visible to the naked eye

[menager31]

What is the maximum wavelength of m101 seen from the Earth by eye?

 

[chemisttree]

Do you mean longest wavelength? If so, that would be red (~700 nm). The H-alpha is the most intense emission line.

http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?letter=.&classic=YES&bibcode=1985AJ...90..192D&page=&type=SCREEN_VIEW&data_type=PDF_HIGH&send=GET&filetype=.pdf

If you mean brightest wavelength, I haven't a clue.

 

[menager31]

longest, thanks