A revised effective-temperature calibration for the DDO photometric system

CLARIA OLMEDO, JUAN JOSÉ; PIATTI, ANDRÉS E.; LAPASSET, EMILIO

PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC

Año: 1994 vol. 106 p. 436 - 443

0004-6280

A revised effective-temperature calibration for the David Dunlap Observatory (DDO) photometric system is presented. Recently published photometric and spectroscopic observations of field and open-cluster G and K stars allow a better definition of the solar-abundance fiducial relation in the DDO C0(45-48) vs. C0(42-45) diagram. The ability of the DDO system to predict MK spectral types of G and K giants is demonstrated. The new DDO effective temperature calibration reproduces satisfactorily the infrared temperature scale of Bell and Gustafsson (1989). It is shown that Osborn's (1979) calibration underestimates the effective temperatures of K giants by approximately 170 K and those of late-type dwarfs by approximately 150 K.