COMMISSION 27 OF THE I. A. U.
         INFORMATION BULLETIN ON VARIABLE STARS
                     Number 2271

                                     Konkoly Observatory
                                     Budapest
                                     1983 January 21

                                     HU ISSN 0374-0676


      TIMES OF MINIMUM LIGHT AND THE LIGHT ELEMENTS FOR Y CVn


  Three times of minimum light of the semiregular variable carbon star Y CVn
were derived from photoelectric measurements made at Brno Observatory in the
years 1980-82. Six other times are based on visual observations of Biskupski
(1963) and on photoelectric measurements of Dzervitis et al. (1979). All the
minima observed are collected in the following table:

 JDMin       O-C    Observer    JDMin        O-C    Observer

  2436100    2.5   Biskupski   2442140      -0.7   Dzervitis
     6350    0.7   Biskupski      4410      -3.1   Vetesnik
     6600   -1.1   Biskupski      4660       1.3   Vetesnik
  2441630   -7.1   Dzervitis      5165       2.7   Vetesnik
     1890    1.1   Dzervitis

  The minima JD 244 1630, 4660 and 5165 were computed from the three colour
observations. The minima JD 244 1890, 2140 and 4410 are based only on a few
observations and were derived by means of the mean light curve of the star.
  The minima are in good agreement with the light elements:

             JDMin = 243 6097.5 + 251.8 E

The new period P = 251.8 days corresponds very well to that noticed in the
paper by Biskupski (1963) but it quite disagrees with the mean period given
for Y CVn in the General Catalogue of Variable Stars ( P = 158 days).



                   M. VETESNIK
           Department of Astronomy, Brno University
               61137 Brno, Czechoslovakia




References:
Biskupski, A., 1963, Urania 34, 187
Dzervitis, U., Paupers, O., Spulgis, G., 1979, Issl. solnca i krasnych zvezd
  9, 5 [BIBCODE 1979ISKZ....9....5D ]




                           ERRATA

The minimum times for six binaries published in IBVS No. 2159 contain
erroneous light-time corrections plus a misprint in the case of ST Aqr. The
correct times are as follows.



Binary           H JD 2400000+

ST Aqr        44841.3903+-0.0004
RW CrB        44780.4066+-0.0002
              44783.3126+-0.0010
V836 Cyg      44840.4224+-0.0003
              44842.3826+-0.0002
TZ Lyr        44784.4100+-0.0005
BB Peg        44812.5030+-0.0003
DI Peg        44893.4270+-0.0002
              44848.4100+-0.0002





            E. DERMAN, N. YILMAZ, S. ENGIN
            Z. ASLAN, C. AYDIN, Z. TUFEKCIOGLU

            University Observatory
            A.U. Fen Fakultesi
            Ankara, Turkey