A new DDO calibration of effective temperature for evolved late-type stars

A.E. PIATTI, J.J. CLARIÁ

Mar del Plata

Congreso; Reunión Anual 37 de la Asociación Argentina de Astronomía; 1992

Asociación Argentina de Astronomía

The DDO Co(45-48) versus Co(42-45) diagram for luminosity classes I, III, and V stars is redefined and the ability of the DDO system to assign MK spectral types is examined. Using the scale of Bell & Gustafsson (1989, MNRAS, 236, 653) as reference, a new DDO calibration of effective temperature is presented. It is shown that the original Osborn's scale underestimates the temperature in about 170 K. This paper will be published in detail elsewhere.