Profiles of Strong Lines in K-Dwarfs

A study of the profiles of strong lines in two stars E Eridani and Gmb 1830 has been done. The following lines were investigated: Ha; D1 and D2 lines of Na I; H- and K-lines of Ca ii; and the infrared triplet lines of C a ii. Model atmospheres were constructed in the majority of cases investigated, using a scaled solar (T-r) relation. Line profiles were then constructed. For E Eridani, all the profiles could be explained well with the use of solar composition and with effective temperature, T, = 5050 K. For Gmb 1830, all the profiles except Ha could be explained well with T = 5000 K and hydrogen-to-metal ratio of twenty times the solar value, with sodium depleted more with respect to that of the solar value by a factor of 2. For Ha, the effect of convection is shown to have some effect. In a parallel calculation, it was found that the calculated and the observed profiles for the Sun do not agree if the B6hm-Vitense (T-r) relation is used.