COMMISSION 27 OF THE I. A. U.
            INFORMATION BULLETIN ON VARIABLE STARS
                       Number 2552

                                        Konkoly Observatory
                                        Budapest
                                        16 July 1984

                                        HU ISSN 0374-0676



         PRELIMINARY ORBITAL ELEMENTS OF HD 184035


  The star HD 184035 (HR 7422) was discovered by Waelkens and Rufener (1983)
to be an eclipsing binary.
  They also presented the V photoelectric observations and the following
light elements:

          Min 1 = JD Hel 2444833.830 + 4.62988d E

HD 184035 is a known single lined spectroscopic binary (Buscombe, Morris 1961)
with an estimated orbital period in agreement with the photometric period.
In this paper photoelectric observations are processed yielding the first
set of orbital elements.
  Because of the small number of observations, this solution is regarded as
preliminary. For the analysis of the light curve the frequency domain
approach was chosen (Kopal 1979). The solution was obtained in e completely
automatized manner by relevant computer programs (Gaspani 1984), fitting
both minima. My computation indicates that the primary minimum is a transit,
the orbital elements are given in Table I.

                    Table I

                 Orbital elements

                Min 1 = transit
                u1 = 0.50 (assumed)
                u2 = 0.50 (assumed)
                r1 = 0.214 +- 0.006
                r2 = 0.082 +- 0.004
                i = 82.6 deg +- 0.8 deg
                L1 = 0.898
                L2 = 0.102

Since the relative radii of both components are small, a detached configuration 
was assumed for the system. In order to combine photometric and spectroscopic 
elements an estimate of the mass ratio is required. Since the
spectroscopic mass ratio is unknown an estimate for q = (m2/m1) was obtained
by the ratio of the fractional luminosity and making the assumption that
both components are on the main sequence (Houck 1978). The following 
statistical relation, fitting the main sequence data:

        log(m2/m1) approx.= 0.30 log(L2/L1)

yields approx.= 0.52. The combination by the mass function given by Buscombe and
Morris yields the following values for masses and radii of the two components
of HD 184035:

            m1 approx.= 2.8 M Sun
            m2 approx.= 1.5 M Sun
            R1 approx.= 4.0 R Sun
            R2 approx.= 1.8 R Sun
            
  This work is regarded as preliminary because new spectroscopic and photometric
observations are needed in order to carry out a more detailed analysis
of this binary system.


                   GASPANI A.

           Osservatorio Astronomico Brera-Merate
           Via E. Bianchi, 46
           22055 Merate (CO)
           Italia

References:

Buscombe W., Morris P.M.: 1961, Mon.Not.R.Astr.Soc., 123, 81 [BIBCODE 1961MNRAS.123..183B ]
Gaspani A., to be published
Kopal Z., 1979, "Language of the Stars", D. Reidel Publ. [BIBCODE 1979ASSL...77.....K ]
Waelkens C., Rufener F., 1983, Astron.Astrophys.Suppl., 52, 13 [BIBCODE 1983A&AS...52...13W ]
Houck N.; 1978, Michigan Cat. of Two Dimensional Spectral types for the
    HD-stars, Vol.2. [BIBCODE 1978mcts.book.....H ]