COMMISSION 27 OF THE I. A. U.
          INFORMATION BULLETIN ON VARIABLE STARS
                       NUMBER 893

                                  Konkoly Observatory
                                  Budapest
                                  1974 June 4


     LONG SERIES OF OBSERVATIONS ON GL, KP, AND V343 Cyg


   The plates on a Cygnus region of the Milky Way taken at the
Maria Mitchell Observatory and spanning more than fifty years are
suitable for testing the accuracy and constancy of variable star
periods. For this purpose Bonnie Buratti, a student summer assistant
from the Massachusetts Institute of Technology, in 1973 examined
the three variable stars in Tables I-III, but she did not have
time to complete all of the necessary analyses.

                 Table I. GL Cyg
Reference        JD_hel      Period    Time Span
Olmsted 1951     31997.746   3.37053   1926-1948
Kukarkina 1955   25512.341   3.37066   JD 13836-34477
Romano 1969      25512.420   3.370683     37468-37889
NEW                          3.37070      22906-42187

The new period (reciprocal 0.2966743) representing 600 Nantucket
plates also satisfies the previously published JD_hel as well as the
observations published by Kukarkina and Romano.

                  Table II. KP Cyg
GCVS              34536.813   0.855940
Whitney 1956                  0.855933  JD 33617-35299
Romano 1969                   0.855940     37189-39061
NEW                           0.855936     22609-41963

The General Catalogue of Variable Stars refers to Whitney's paper
but the periods differ slightly. The reciprocals of the periods
are respectively 1.168316 (Whitney)  and 1.168306 (GCVS). The new
period (reciprocal used, 1.168311) fits the 1040 Nantucket observations
and also the data published by both Whitney and Romano. Moreover,
the scatter of observations on the ascending branch of the
light curve is smaller than for either of the previously published
periods.

                 Table III. V343 Cyg              
Baade 1928       24080.43     11.9290     
Olmsted 1951     31236.737    11.9275   1926-1948
Romano               "                  JD 37189-39061  
NEW                  "                     22609-42187 
                                
                  [FIGURE 1]
                  V343 Cyg
                  A is BD +38 3884

In this instance the period derived by Olmsted on the basis of
less than sixty plates, and verified by Romano, holds equally well
without correction for the 670 Nantucket observations.
For none of the three stars investigated is there any indication
of changing period in the course of 50 to 60 years.

May 1974

                            DORRIT HOFFLEIT
                        Maria Mitchell Observatory
                         Nantucket, Mass., U.S.A.





References:

Baade, W. 1928, A.N. No. 5548, [BIBCODE 1928AN....232...65B ]
Kukarkina, N.P. 1955 Russian Var. Stars, Vol. 10, p. 96.
Olmsted, M. 1951, Harvard Bull. No. 920. [BIBCODE 1951BHarO.920...12O ]
Romano, G. 1969, Padua Pub. No. 156.
Whitney, B.S. 1956, P.A.S.P., Vol. 68, p. 269. [BIBCODE 1956PASP...68..269W ]