Recent radiative lifetime measurements accurate to +/- 5% (Stockett et al.
2007, J. Phys. B 40, 4529) using laser-induced fluorescence (LIF) on 8
even-parity and 62 odd-parity levels of Er II have been combined with new
branching fractions measured using a Fourier transform spectrometer (FTS) to
determine transition probabilities for 418 lines of Er II. This work moves Er
II onto the growing list of rare earth spectra with extensive and accurate
modern transition probability measurements using LIF plus FTS data. This
improved laboratory data set has been used to determine a new solar
photospheric Er abundance, log epsilon = 0.96 +/- 0.03 (sigma = 0.06 from 8
lines), a value in excellent agreement with the recommended meteoric abundance,
log epsilon = 0.95 +/- 0.03. Revised Er abundances have also been derived for
the r-process-rich metal-poor giant stars CS 22892-052, BD+17 3248, HD 221170,
HD 115444, and CS 31082-001. For these five stars the average Er/Eu abundance
ratio, = 0.42, is in very good agreement with the
solar-system r-process ratio. This study has further strengthened the finding
that r-process nucleosynthesis in the early Galaxy which enriched these
metal-poor stars yielded a very similar pattern to the r-process which enriched
later stars including the Sun.Comment: 20 pages, 4 tables, 10 figures; To be published in the Astrophysical
Journal Supplemen