We present an analysis of candidate members of the \eta Cha and MBM 12A young associations .
For an area of 0.7 deg ^ { 2 } toward \eta Cha , we have performed a search for members of the association by combining JHK _ { s } photometry from 2MASS and i photometry from DENIS with followup optical spectroscopy at Magellan Observatory .
We report the discovery of three new members with spectral types of M5.25-M5.75 , corresponding to masses of 0.13-0.08 M _ { \odot } by theoretical evolutionary models .
Two and three of these members were found independently by Lyo and coworkers and Song and coworkers , respectively .
Meanwhile , no brown dwarfs were detected in \eta Cha down to the completeness limit of 0.015 M _ { \odot } .
For MBM 12A , we have obtained spectra of three of the remaining candidate members that lacked spectroscopy at the end of the survey by Luhman , all of which are found to be field M dwarfs .
Ogura and coworkers have recently presented four “ probable ” members of MBM 12A .
However , two of these objects were previously classified as field dwarfs by the spectroscopy of Luhman .
In this work , we find that the other two objects are field dwarfs as well .