In 2019, the Research and Education Collaborative Occultation Network (RECON) obtained multiple-chord occultation measurements of two Centaur objects: 2014 YY₄₉ on 2019 January 28 and 2013 NL₂₄ 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 km and a geometric albedo for 2014 YY₄₉ and a radius km and a geometric albedo for 2013 NL₂₄. 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.

在2019年，研究与教育合作掩星网络（RECON）获得了两个半人马座物体的多弦掩星测量：2019年YY ₄₉于2019年1月28日和2013年NL ₂₄于2019年9月4_日。观察外部太阳系物体的高不确定性掩星。采用圆形型号为对象轮廓，推导半径公里和几何反照率为2014 YY ₄₉和半径公里和几何反照率为2013 NL ₂₄。为了这些测量的精度，没有检测到任何物体的大气或环。这里测量的两个物体是用恒星掩星技术测量的最小距离物体。除了这些几何约束之外，掩星测量还以比直接成像可行的精度更高的精度为这两个半人马座提供了天体测量约束。为了补充掩星效果，我们还对Pan-STARRS调查进行了彩色光度分析，以限制这两个半人马的旋转光曲线幅度和光谱颜色。我们建议将来的工作集中在光度学上，以更加有意地限制对象的颜色和光曲线幅度，以及在这种天体测量学指导下的后续掩星工作。