  In 2019, the Research and Education Collaborative Occultation Network (RECON)
obtained multiple-chord occultation measurements of two centaur objects: 2014
YY$_{49}$ on 2019 January 28 and 2013 NL$_{24}$ on 2019 September 4. RECON is a
citizen-science telescope network designed to observe high-uncertainty
occultations by outer solar system objects. Adopting circular models for the
object profiles, we derive a radius $r=16^{+2}_{-1}$km and a geometric albedo
$p_V=0.13^{+0.015}_{-0.024}$ for 2014 YY$_{49}$, and a radius $r=66
^{+5}_{-5}$km and geometric albedo $p_V = 0.045^{+0.006}_{-0.008}$ for 2013
NL$_{24}$. To the precision of these measurements, no atmosphere or rings are
detected for either object. The two objects measured here are among the
smallest distant objects measured with the stellar occultation technique. In
addition to these geometric constraints, the occultation measurements provide
astrometric constraints for these two centaurs at a higher precision than has
been feasible by direct imaging. To supplement the occultation results, we also
present an analysis of color photometry from the Pan-STARRS surveys to
constrain the rotational light curve amplitudes and spectral colors of these
two centaurs. We recommend that future work focus on photometry to more
deliberately constrain the objects' colors and light curve amplitudes, and on
follow-on occultation efforts informed by this astrometry.
