COMMISSION 27 OF THE I. A. U.
        INFORMATION BULLETIN ON VARIABLE STARS
                    NUMBER 585

                              Konkoly Observatory
                              Budapest
                              1971 October 18



       ELEMENTS AND CURVES OF THE TWO INFRARED
          VARIABLES MO AND MP CASSIOPEIAE


     The variable stars MO and MP Cas have been discovered 
by Rosino (1953) as infrared stars of variable brightness 
within the nebulosity surrounding the peculiar nebula
NGC 7635. In the recent General Catalogue of Variable Stars
of Kukarkin et al. (1970) they are both classified as 
irregulars type I_n.
     In the course of a research on the field of NGC 7635
which is carried out at the Astrophysical Observatory of
Asiago, we have had the possibility of examining a series
of infrared photographs (IN + RG5) taken from 1962 to 1971,
Both MO and MP Cas are Mira variables. Their mean infrared
light curves are reproduced in Figs. 1 and 2, The following
elements have been derived:


MO Cas: T_0= 243 7901; P = 252.25d; Infrared amplitude 2.75
        between 10.25 and 13.0.
MP Cas: T_0= 243 7875; P = 334.5d; Infrared amplitude 2.80
        between 10.35 and 13.15.

                      [FIGURE 1]
                      [FIGURE 2]

      The light curves are typical of the Mira Variables;
with a very moderate dispersion. Rough estimates of 
objective-prism spectra taken near maximum show that they are
not earlier than M4-M5. Both stars are invisible in the
blue, even at maximum.


                         L. ROSINO
                        D. DI MARTINO
                 Astrophysical Observatory, Asiago



References: L. ROSINO, 1953, Bologna Pubbl. Vol. VI. No. 3.