COMMISSION 27 OF THE I. A. U.
       INFORMATION BULLETIN ON VARIABLE STARS
                    NUMBER 305


                                   Konkoly Observatory
                                   Budapest
                                   1968 October 29



       PHOTOELECTRIC OBSERVATIONS OF YZ CMi


     By the request of Working Group on UV Ceti type
Stars a continuous photoelectric monitoring of YZ CMi was
carried out at the Lick Observatory on Jan 23 and 24, 1968,
U.T. The observations were obtained with the 24 inch 
reflector of the Lick Observatory and a blue filter of the
UBV system. The variable was monitored in total for 11 hours.
The star BD +3deg1778 was used as a comparison star and 
observed 15-20 minutes. A few occasional three color measurements
of both stars were also obtained. Here, only the data
concerning flares of YZ CMi are presented. They are given
in the Table. All the columns are self-explanatory. The 
occurrence of the third flare is uncertain. The star had a
large western hour angle and, as a result, atmospheric
fluctuations were relatively large. The flare had two narrow
maxima poorly defined against the fluctuations.

      Flares of YZ CMi observed at the Lick Observatory

Date    Time of                       Flares
(U.T.)  Monitoring     Time of  Delta b instr. Duration
        (U.T.)         Maximum      (mag)      (minutes)
                        (U. T.)
Jan 23   4h11m-7h28m     6h37m      0.20        1
         7h40m-8h17m
Jan.24   3h54m-5h48m
         6h08m-7h42m
         7h56m-10h27m    9h26m      0.23        1.5
         10h37m-11h52m   11h40m     0.2         1


Warsaw University Observatory
Warsaw, Poland

K. STEPIEN



                          AF AURIGAE


      Le Catalogue General d'Etoiles Variables (1958)
donne, pour cette variable semi-reguliere tres rouge
(spectre N) decouverte par Espin, les magnitudes 
photographiques max. et min. 11,3-11,8 (1).
      J'ai etudie cette etoile sur 105 plaques de la
Station de Mainterne dont 99 ont ete obtenues entre les
dates JJ 2437639 et 2438524. AF Aurigae fluctue generalement
                  entre m_p 13,0 et 13,5 par comparaison
                  avec les etoiles de la
                  S.A.25 de Harvard (2). Les maximums
                  que j'ai observes sont 12,3
                  (JJ 2438433) et 12,4 (JJ 2438465).
                  Cette variable est invisible sur
                  deux plaques (JJ 2437839 et 2437960)
    [FIGURE 1]    
                  montrant une etoile de m_p 14,11 de
                  la S.A. 25 de Harvard. Sur une plaque
                  (JJ 2436607) montrant deux etoiles
                  de m_p 14,20 et 14,40 de la meme
                  S.A.25, AF Aurigae est estimee 14,5
                  environ. Sur la planche 0-645 du
                  "Sky Survey" de l'Observatoire du
                  Mt. Palomar, la magnitude 
                  photographique est evaluee 13,5 environ.





19 Octobre 1968

                          ROGER WEBER

                    Station Astrophotographique
                          de Mainterne
                         (Eure-et-Loir)
                            France





(1) Selon Gaposchkin (H.A.118, no 16, 123, 1952): "minimum is
   about 11, 80".
(2) AF Aurigae est stiuee a 43' a l'Est de l'etoile centrale
   de la S.A. 25.