dM stars are among the smallest, coolest and longest-lived types of stars. They are good targets for finding small planets, since a small planet can have a relatively large influence on the motion of a small star like a dM star. Hence, understanding the behaviors of this class of star helps astronomers searching for Earth-like planets in their habitable zone, and advances other fields like stellar evolution.

Dr. Pablo Mauas, an astronomer from Argentina, visited NAOC on July 7, 2014, and gave a presentation about his research which focuses on dM stars. He has collected data on dM stars over the last decade by observing particular lines in their spectra. These spectral lines are sensitive to small changes in temperature and pressure that occur in the atmospheres of dM stars. By combining the spectral data he collected with data from other spectral studies and long-term photometric monitoring, he has uncovered patterns in the behaviors of dM stars, such as flares and star spots. By studying the resulting cycles in these data, he has even found double dM stars which have close orbits. The behaviors of the stars in these binaries appear to be linked in the sense that both stars generate flares and star spots in a synchronized manner. Since the atmospheres of these double dM stars are not physically in contact, he speculates that their magnetospheres are interacting, for example, by stimulating waves that trigger this synchronized activity. The results of Dr. Mauas' research can give astronomers new insights into the behavior and evolution of dM stars.