Mean light curves of long-period variables and discrimination between carbon- and oxygen-rich stars^*

¹ Université Montpellier II, Groupe de Recherche en Astronomie et Astrophysique du Languedoc, Unité associée au CNRS, F-34095 Montpellier Cedex 5, France
² Université des Sciences El Jadida, Maroc
³ American Association of Variable Star Observers, 25 Birch Street, Cambridge, Massachusetts 02138-1205, U.S.A.

Received: 13 September 1996
Accepted: 16 November 1996

Abstract

Using 75 years of AAVSO data, mean light curve parameters of a sample of 355 long period M, S, and C mira and semi-regular variable stars are investigated. We present a classification of the light curves of LPVs into 6 distinct groups. Combining this classification with IRAS colors makes it possible to distinguish oxygen-rich from carbon-rich miras.