Some 170 of these systems have been discovered by the 2MASS survey, including several with prominent methane lines.
Some 170 of these systems have been discovered by the 2MASS survey, including several with prominent methane lines. They have also been discovered by the WISE survey. One class of these objects is characterized by absorption bands for titanium and vanadium oxide and iron and chromium hydride. Based on their spectral type, these objects are subdivided into the classes T, L, and Y. Tiede 1 was the first of these objects discovered; another of these objects is the companion star Gliese 229B. There is little variation in the radii of these objects, making it difficult to distinguish them from planets. Because these objects are too light to sustain nuclear fusion, they are typically characterized using the lithium test. For 10 points, name these astronomical objects that are a type of cool, low mass star.
Some 170 of these systems have been discovered by the 2MASS survey, including several with prominent methane lines.
brown dwarf [or brown dwarves]