Photometric observations in the near infrared for 161 S stars, including 18 Tc-rich (intrinsic) stars, 19 Tc-deficient (extrinsic) ones and 124 candidates for Tc-deficient S stars, are presented in this paper. Based on some further investigations into the infrared properties of both Tc-rich and Tc-deficient S stars, 104 candidates are identified as very likely Tc-deficient S stars. The large number of infrared-selected Tc-deficient S stars provides a convenient way to study the physical properties and the evolutionary status of this species of S stars.

Cone search capability for table J/A+A/387/129/table3 (Observed candidates for Tc-deficient S stars)

Cone search capability for table J/A+A/387/129/table1 ({alpha}12 values of the S stars whose Tc contents are well known.)