The HI n=22-21 Rydberg line has been detected for the first time as excess emission at the limb of the Sun. Intense limb brightening has been observed, in agreementwith that measured for the the n=20-19 line (Clark et al. 2000). The width of this feature is consistent with the width of the n=20-19 line. This measurement represents the highest-n Rydberg line detected to date in the solar spectrum and places a further constraint on models of the lower chromosphere.
© European Southern Observatory (ESO) 2000
Online publication: October 10, 2000