The largest sample of brown dwarfs

The first brown dwarf - a star but for which the mass is too low to ignite hydrogen in the core i.e. a failed star - was discovered in 1995, and there are now hundreds known, and the sequence of cool stars has been extended beyond M, with the creation of spectral types L and T. We recently developed a new search technique and compiled the first large homogeneous sample of over 1000 L and T dwarfs, that is complete over the entire spectral sequence L0 to T8. The sample makes it possible to measure the properties of the LT population accurately for the first time. The PhD student will, inter alia, use the sample to compute the substellar luminosity function, and the disk scale height. They will also obtain spectra of a subsample and reconsider the standard spectral classification scheme using these spectra, as well as machine learning tools, and execute a search for very young brown dwarfs, which have low mass. These are nearby objects of planetary mass, closer than known exoplanets, and easier to study spectroscopically, and therefore very useful to exoplanet studies.