Transition probabilities in Pr(II) and the solar praseodymium abundance

Branching ratios have been measured for all of the known transitions from five levels in Pr+. The known mean lifetime of four of these levels were used to compute transition probabilities for 40 transitions. Five of the stronger lines are seen in the sun. The equivalent widths of Moore et al. and the solar model parameters of Righini and Rigutti were used to compute the photospheric Pr adundance: log (Nsub(Pr)/Nsub(H)) + 12 = 0.66 +- 0.15. This value is a factor of ten lower than the most recent photospheric abundance measurement of Grevesse and Blanquet. The difference arises in part from the new transition probabilities, in part from the equivalent widths. The use of widths from Moore et al. is justified by comparing them with widths measured on the Preliminary Kitt Peak Solar Atlas. (author)