  We present a catalog of absorption lines in the z', Y, and J bands that we
identified in 21 Lyn, a slowly rotating A0.5 V star. We detected 155 absorption
features in the high-resolution (0.90-1.35 um, R = 28,000) spectrum obtained
with the WINERED spectrograph after the telluric absorption was carefully
removed using a spectrum of a B-type star as a telluric standard. With a visual
comparison with synthetic spectra, we compiled a catalog of 219 atomic lines
for the 155 features, some of which are composed of multiple fine structure
lines. The high-quality WINERED spectrum enabled us to detect a large number of
weak lines down to ~1% in depth, which are identified for an A-type star for
the first time. The catalog includes the lines of H, C, N, O, Mg, Al, Si, S,
Ca, Fe, and Sr. These new lines are expected to be useful for spectral
classification and chemical abundance analyses, whilst the line list is useful
for observers who plan to use A-type stars as telluric standards because it is
necessary to distinguish between stellar lines and telluric absorption lines in
high-resolution spectra. ASCII versions of the spectra are available in the
online version of the journal.
