COMMISSION 27 OF THE I. A. U.
           INFORMATION BULLETIN ON VARIABLE STARS
                       Number 2861

                                         Konkoly Observatory
                                         Budapest
                                         7 February 1986

                                         HU ISSN 0374 - 0676



          REVISED ELEMENTS FOR THREE ECLIPSING BINARIES


  V 646 Cas

  Photoelectric observations made by Faulkner (1985) indicated that the
preliminary elements published by the present author (1982) were incorrect.
The elements given by Faulkner could be confirmed and refined from new 
observations made at Hartha (1965-1975) and Sonneberg (1956-1959 and 1974-1983)
(altogether 289) sky-patrol plates and a rediscussion of the former material.
  A weighted least squares analysis of 8 normal minima and the secondary
minimum of Faulkner's paper yields the following elements:

  Min.hel. = J.D. 2446028.040 + 6.162491d*E       (EB) (10.04m-10.55m/10.33m ph)
                       +-.015  +-.000019

  V 450 Her

  This star has been known for its variable period since the paper of
Geyer (1968). To cover the last years, 367 sky-patrol plates made at Sonneberg 
Observatory during the years 1962-1983 were used.
  A least squares solution of the 11 newly found minima and the visual
epoch of minimum given by Brelstaff (1985) has yielded the refined elements:

     Min.hel. = J.D.2444635.591 + 0.9127152d*E           (EA) (D= 0.18p)
                         +-.009 +- .0000011


  BV Tau

  The 12.349 days period given in the GCVS is doubtful (Kaho, 1958). Extended 
visual observations made by Brelstaff (1985) showed a 0.93044 day
period for this EB-type binary. To confirm Brelstaff's results, the magnitudes
on 140 Hartha sky-patrol plates (1959-1977) were derived. Eight new times of
minimum were found and a least-squares solution (including the epoch given
in Brelstaff's paper) has yielded the improved linear elements:

     Min.hel. = J.D. 2446052.618 + 0.9304536d*E          (EB)
                          +-.017  +-.0000023    (11.10m-11.95m/11.55m ph)

  Further particulars will be published in the Mitteilungen der Bruno-H.-
Burgel Sternwarte Hartha.





                          THOMAS BERTHOLD

                       Bruno-H.-Burgel Sternwarte
                          DDR-7302 Hartha




References:

Berthold, T., 1982, Mitt. Bruno-H.-Burgel-Stw. Hartha, 17, 14.
Brelstaff, T., 1985, Brit. Astron. Ass. V.S.S. Circ., 59.
Faulkner, D.R., 1985, Inf. Bull. Var. Stars, No. 2702.
Geyer, E.H., 1968, Mitt. Remeis-Stw. Bamberg, VII, 72.
Kaho, S., 1958, Tokyo Bull. (II), 30.