COMMISSION 27 OF THE I. A. U.
         INFORMATION BULLETIN ON VARIABLE STARS
                      NUMBER 133

                                              Konkoly Observatory
                                              Budapest
                                              9 May 1966

                       RT CETI

                      [FIGURE 1]

The variable star RT Ceti was discovered by Emily M. Hughes
in 1930 (HB, No. 877, 1930), and was described as of short period.
Apparently, no other study of this star has been made.
During another investigation, the writer made about 700 observations 
of RT Ceti. A portion of these (principally from plates
taken with Harvard's 3-inch patrol cameras) is shown in the accompanying 
light curve. It appears that the star has relatively long intervals 
of small fluctuations (about 0.3  magnitude), while at other times its
variation is > 0.5 magnitude. One change of 0.9 magnitude occurred
in 30 days. The photographic range of RT Ceti was found to be
10.6-11.7.
One well-exposed objective-prism spectrum (a 60-minute exposure 
in 1906 with the 24-inch Bruce doublet, then at Arequipa, Peru)
was found and classified as M6.
It is concluded that RT Ceti is a late-type irregular variable.

                                      
					        L. J. ROBINSON
                                              "Sky and Telescope"
                                              49 Bay State Rd.
                                             Cambridge, Mass. USA