COMMISSION 27 OF THE I.A.U.
                 INFORMATION BULLETIN ON VARIABLE STARS
                             Number 3205

                                                         Konkoly Observatory
                                                         Budapest
                                                         20 June 1988

                                                         HU ISSN 0374 - 0676


     ON THE RECENT PERIOD CHANGE OF THE RR LYRAE STAR XZ CYGNI

Bezdenezhnyi (1988) gave a system of nine linear elements for XZ Cygni,
which is known for its large period changes. The elements no. 9 of the
quoted paper, however do not fit the observations from 1984 onwards, because
they had been derived from too,short a time interval (2445200 to 6300).
   From numerous maxima observed by Blasberg (1983a, 1984, 1985, 1986, 1988)
the following elements could be secured:

       Max. hel, = 2445546.4160 + 0.4666215d E

They follow those given by Blasberg (1983b) or no. 8 of Bezdenezhnyi (1988) and
are valid from 1983.7 up to the present. They are confirmed for instance by
the BAV data of Wunder (1987a, b). The difference between the observed
maxima and the dates computed by no. 9 of Bezdenezhnyi (1988) amounted to
about 0.06d = 1.4h in 1987. Details will be published in Mitt. Veranderl.
Sterne 11, p.117 ff.


H.-J. BLASBERG                      W. WENZEL

Arbeitskreis "Veranderliche"(AKV)   Sternwarte Sonneberg
im Kulturbund der DDR               Zentralinstitut fur Astrophysik
DDR-8053 Dresden,                   der Akademie der Wissenschaften
Tolkewitzer Strase 44               der DDR



References:

Bezdenezhnyi, P.P., 1988, Inform. Bull. Variable Stars No. 3141.
Blasberg, H.J., 1983a, Mitt.Veranderliche Sterne, 10, 44.
Blasberg, H.J., 1983b, Inform. Bull. Variable Stars No. 2361.
Blasberg, H.J., 1984, Mitt. Veranderliche Sterne, 10, 105.
Blasberg, H.J., 1985, Mitt. Veranderliche Sterne, 10, 164.
Blasberg, H.J., 1986, Mitt. Veranderliche Sterne, 11, 20.
Blasberg, H.J., 1988, Mitt. Veranderliche Sterne, in preparation
Wunder, E., 1987a, BAV Rundbrief, 36, Nr. 1. [BIBCODE 1987BAVRu..36....2W ]
Wunder, E., 1987b, BAV Rundbrief, 36, Nr. 4. [BIBCODE 1987BAVRu..36..157W ]