A 2024 Nature paper by Jerry Xuan et al. identified one of these objects as a close binary; that first one of these objects to be spectroscopically confirmed was discovered by a team including Shrinivas Kulkarni and Rebecca Oppenheimer. The top-left corner of a mass-period plot, known as their “desert,” (10[1])contains (10[1])unexpectedly few of these objects. A strong 2-micron (-5[1])methane absorption band, (-5[1])as observed by the 2MASS survey, (10[1])is exemplified by (10[1])Gliese 229B, the (-5[1])prototypical (-5[2])example of the T spectral type. These degenerate objects are spectroscopically distinguished from M (10[1])stars by the presence of lithium. (10[1])These (10[2])objects can fuse deuterium despite being (10[1])lighter (-5[1])than the (10[1])0.08 (10[1])solar masses required to initiate (-5[1])p-p chain (10[1])fusion. The very bottom right of the H–R diagram contains, for 10 points, what substellar objects, (10[1])often called “failed (10[1])stars”? (10[1])■END■ (10[9])