As is customary now in Arizona, the sky was full of thin cirrus at the
start of the night. However, spectropolarimetry proceeded without much
difficulty for the first two hours. This allowed multiple observations
of CTA102 and three other blazars before they set. Then, thicker clouds
moved in at around 2100 local time. The clouds, combined with bright
moonlight, stopped operations until just after midnight. Sky conditions were
reasonable, with some periods of completely clear skies, until nearly 0400 when
more light cirrus combined with moonlight slowed operations down. The seeing
was excellent during the first three-quarters of the night at about 1 arcsec.
After that, it degraded to about 2 arcsec with short bursts of up to 3 arcsec.
In all, over 15 blazars were observed and a little photometry was accomplished.
