COMMISSION 27 OF THE I. A. U.
         INFORMATION BULLETIN ON VARIABLE STARS
                   Number 2218

                                  Konkoly Observatory
                                  Budapest
                                  1982 October 25

                                  HU ISSN 0374-0676


          PHOTOMETRIC VARIABILITY OF HR 3119


  HR 3119 is a double-lined spectroscopic binary with components
of similar spectral types. Young and Koniges (1977) have given
an F8V spectral classification based on a spectrum obtained at
an epoch when the lines of the components were not resolved. The
orbital period of the binary is 11.08 days and mass ratio of the
components is very close to unity (Harper 1939).
  We included HR 3119 in a photometric programme of late type
emission binaries on the basis of its classification as a radio
binary by Spangler et al. (1977). The star was observed with the
34-cm Cassegrain reflector of the Kavalur Observatory through
standard B and V filters. Observations were made on 15 nights
between December and January 1979-80. HD 65301 and HD 67224 were
observed along with HR 3119 as comparison stars. The figure is
a plot of differential magnitudes against phase computed with
the following ephemeris (Eaton et al. 1981):

          JD = 2444530.0 + 10.17d E.

Each point is an average of three or four independent measurements
of a single night and the total uncertainty of a point is
~ 0.008 mag. The light curve is nearly sinusoidal with an amplitude
of ~ 0.04 mag. The B-V colour does not show any significant
variation. Eaton et al. (1981) observed the star on five nights
during the interval covered by our observations and these fall
on the mean light curve shown in the figure.
  From the spectral class, Ca II H and K emission photometric
light variation and radio emission, Eaton et al. classify
HR 3119 as a member of RS CVn binaries. Young and Koniges (1977),


                          [FIGURE 1]


from a spectrum obtained in the single-lined phase, find that
the radial velocity derived from the Ca II H and K emission lines
are more negative by 22 kms^-1 than that derived from the absorption 
lines and so the emission might not be of chromospheric
origin. HR 3119 stands out in several aspects from the classical
RS CVn systems. All of the classical RS CVn binaries have near-
circular orbits and their photometric and orbital periods differ
very little due to orbital synchronisation. The higher eccentricity 
(e = 0.11) of the orbit observed in the case of HR 3119 may
be the reason for the significant difference in its orbital and
photometric periods. In a typical RS CVn system the spectral
type of the secondary component is ~K0, whereas both the components
of HR 3119 are of earlier spectral types (~F8). In this respect
this star resembles sigma2 CrB, where the components are F6 and G1.
Spangler et al., in their radio survey of close binaries, find
that these two stars are the least luminous among the known
radio binaries. More systematic observations, both photometric



and spectroscopic, are necessary to understand the peculiarities
of this binary.





           M.V. MEKKADEN

           A.V. RAVEENDRAN

           S. MOHIN

           Indian Institute of Astrophysics
           Bangalore 560034
           India





 References:
 Eaton, J.A., Hall, D.S., Henry, G.W., Vaucher, C.A., Louth, H.
   and Skillman, D.R., 1981, Astrophys. Sp. Sci. 80, 405 [BIBCODE 1981Ap&SS..80..405E ]
 Harper, W.E., 1939, Publ. Dominion Astrophys. Obs. 7, 149 [BIBCODE 1939PDAO....7..149H ]
 Spangler, S.R., Owen, F.N. and Hulse, R.A., 1977, Astron. J. 83, 989 [BIBCODE 1977AJ.....82..989S ]
 Young, A. and Koniges, A., 1977, Astrophys. J. 211, 836 [BIBCODE 1977ApJ...211..836Y ]