| Abstract : | Abstract:
M dwarfs are the most numerous stars in our Galaxy, amounting to about two-thirds in number and about 40 percent in stellar mass. M dwarfs are the lowest-mass hydrogen-burning stars, which are found at the bottom of the main sequence in the H-R diagram. These stars possess masses of 0.08–0.6 M⊙ and have effective temperatures of 2500 - 4000 K. We have undertaken optical/Near-IR spectroscopic studies of a unique sample of M-dwarfs including a few M-dwarfs having strong magnetic fields. Using Himalayan Faint Object spectrograph (HFOSC) and TIFR Near-IR spectrograph (TIRSPEC) back-end instruments on the 2-m Himalayan Chandra Telescope (HCT) telescope, we have taken optical and near-IR spectra of a sample of M dwarfs to investigate the chromospheric activity and evolution of the atmosphere of M-dwarfs. Several important atomic and molecular lines in the optical and Near-IR wavelengths (e.g.,(H alpha, Ca II IR triplet, He 10833, Na, CO, etc) will be used to characterize these late-type dwarfs. From a preliminary analysis of our observed spectra, we have detected and identified several important atomic and molecular lines to characterize those dwarfs, and data analysis is ongoing. These observations could be used to establish a road map for future target selection of transit searches around young and old populations of nearby M dwarfs. |
