Spectroscopy of red giants in the open clusters NGC1545 and Tr2

The results of local thermodynamic equilibrium (LTE) abundance analysis are presented for four red giants in the fields of open clusters NGC 1545 and Tr2. The membership of HD 27276, HD 27292 and HD 16068 was confirmed and the age of NGC 1545 was updated: log age(yr) = 7.95. A mild deficiency of iron-group elements was found on average for NGC 1545 and Tr2, [Fe/H] =− 0.13 and −0.07 with an uncertainty of about 0.08 dex. Oxygen and carbon are moderately depleted in all cluster giants, [O/Fe] =− 0.23 ± 0.05 dex and [C/Fe] =− 0.56 ± 0.07 dex on average. Nitrogen is enhanced, [N/Fe] values in range +0.4 to +1.2 dex, and lithium depleted. Sodium is slightly enhanced, [Na/Fe] =+ 0.26 ± 0.04 dex on average. Modified abundances are in agreement with the chemical evolution of intermediate-mass stars on the red giant branch. Some occasional radial velocity variations are probably due to convection in the atmospheres of luminous giants.