Observatory, Cambridge, Massachusetts
RY Carinae is classified in
the General Catalog of Variable Stars
by Kukarkin et al. (1970) as Mira type with period 421.53 days, a brightest
maximum of 9.8m visual and faintest minimum of < 15.0m visual. The notes to
the catalog indicate that average maximum is 11.0m and average minimum 15.0m.
There is also a remark to the effect that, since J.D. 2423600 the period has
decreased to 419 days with considerable variation.