COMMISSION 27 OF THE I. A. U.
           INFORMATION BULLETIN ON VARIABLE STARS
                        Number 3447
                                         Konkoly Observatory
                                         Budapest
                                         27 March 1990

                                         HU ISSN 0374 - 0676


    SAO 23229: A NEW DOUBLE-LINED SPECTROSCOPIC ECLIPSING BINARY

    The discovery of eclipses of the bright star SAO 23229 (HD
14384; V=6.9; Spectral Type F5 V) by Indiana observer Dan Kaiser
was described in a recent article in Sky and Telescope magazine
(MacRobert, 1990). Photoelectric observations by H. Landis and D. Williams,
reproduced in that article, show eclipses of 0.55 mag depth and
period of 2.111 days. No secondary eclipses are reported, leaving 
open the question of whether the system contains a very dim
secondary or whether it consists of two identical stars with an
actual period of 4.2 days. We report here observations that
favor the latter interpretation.
    We have observed SAO 23229 spectroscopically, using echelle
spectrographs on the 1.5 m Wyeth reflector at Oak Ridge Observatory 
and the 1.5 m Tillinghast reflector at Fred L. Whipple
Observatory. High-resolution (10 km/sec) spectra, each covering
a region 45 Angstroms wide centered on 5187 Angstroms were
reduced by cross-correlating them with a high-signal-to-noise
template spectrum of the twilight sky. The procedure is standard
for spectra reduced at the Center for Astrophysics, and details
of the reduction and velocity-measurement techniques have been
documented elsewhere in the literature (Latham 1985).
    Two spectra observed in February, 1990, along with the 
corresponding cross-correlations, are shown in Figure 1. The 
correlations appear double-peaked, evidence that two components are
present in the binary system. Velocities derived from these
peaks for two nights are presented in Table 1. We have here a     
clearly separated double-lined spectroscopic binary with a
velocity semi-amplitude of at least 85 km/sec for each component.
The nearly equal height of the correlation peaks indicates that
the two components of the system are close to one another in
luminosity (Marschall and Mathieu, 1988), while the symmetry of
the velocity excursions around the mean suggests that the 
components are of nearly equal mass. Finally, the velocity semi-
amplitude is consistent with that expected for two F5 V 
components of period 2 to 4 days seen in the plane of the orbit.
   Thus it seems likely that primary and secondary eclipses are
nearly equal in depth and that the 2.1-day period of recurring
eclipses is actually the half the true period of the binary
system. Photometric observers of SAO 23229 should therefore
exercise care to see if one eclipse can be distinguished from
another, allowing precise determinations of the photometric 
characteristics of the individual components of the system.


                       [FIGURE 1a]

 Figure 1a: Spectrum and cross-correlation of SAO 23229 observed
           at Oak Ridge Observatory, H.J.D. 2447935.5988. Two
           nearly equal peaks are observed, labeled 1 and 2.
           Velocities for these components are given in Table 1.

 
                        TABLE 1

      Radial Velocity Observations of SAO 23229

    Heliocentric Julian Date      V1(km/sec) V2(km/sec)
    2447935.5988         	    -43.4   +43.3
    2447942.5089          	    +85.6   -86.9


                       [FIGURE 1b]

 Figure 1b: Spectrum and cross-correlation of SAO 23229 observed
           at Oak Ridge Observatory, H.J.D. 2447942.5089. Two
           nearly equal peaks are observed, labeled 1 and 2.
           Velocities for these components are given in Table 1.


   The two reduced spectra presented here only give a qualitative 
estimate of the relative masses of the components. A full
characterization of the masses of this binary system requires a
determination of the spectroscopic orbital elements along with
precise photometry. We continue to obtain radial velocity
measurements of SAO 23229 with the aim of deriving the full
velocity curve and the orbital elements of the system.
   Thanks to Joyce Rey-Watson for making the resources of the
SIMBAD database available to us for this study.





                LAURENCE A. MARSCHALL
                      Gettysburg College
                      Gettysburg, PA

                ROBERT P. STEFANIK
                      Harvard-Smithsonian Center for
                      Astrophysics
                      Cambridge, MA

                HAROLD L. NATIONS
                      Franklin and Marshall College
                      Lancaster, PA

                 and

                ROBERT J. DAVIS
                      Harvard-Smithsonian Center for
                      Astrophysics
                      Cambridge, MA


REFERENCES

   Latham, D.W. 1985 In Stellar Radial Velocities, IAU Colloquium 
No. 88, edited by A.G.D. Philip and D.W. Latham (Davis,
Schenectady), p. 21. [BIBCODE 1985srv..conf...21L ]
  MacRobert, Alan 1990, Sky and Telescope, 79, 188.
  Marschall, L. A. and Mathieu, R.D. 1988, Astronomical
Journal, 96, 1956. [BIBCODE 1988AJ.....96.1956M ]