While an undergraduate at MIT, he invented the spectroheliograph, and in 1908 he discovered that lines in sunspot spectra are split.
While an undergraduate at MIT, he invented the spectroheliograph, and in 1908 he discovered that lines in sunspot spectra are split. With Walter Adams, he discovered that the polarity of magnetic fields of sunspots reverses every 23 years. FTP, iden  tify this astronomer, who persuaded Charles Yerkes to fund a 40 meter refracting telescope at the University of Chicago, and who went on to bring about the Mount Wilson and Mount Palomar observatories.
While an undergraduate at MIT, he invented the spectroheliograph, and in 1908 he discovered that lines in sunspot spectra are split.
George Ellery Hale