COMMISSION 27 OF THE I. A. U.
       INFORMATION BULLETIN ON VARIABLE STARS
                    NUMBER 378


                                 Konkoly Observatory
                                 Budapest
                                 1969 September 12


           NEW BRIGHT ECLIPSING BINARY

	As a result of a systematic search for eclipses
among a group of double line spectroscopic binaries, not
previously announced to be variable, the star BS 6611 was
found to show primary and secondary eclipses of equal
amplitude.
	The observations were made with the photoelectric
photometer of the Yale University Observatory 20-inch
reflector at the Bethany Observing Station, A RCA 1P21
multiplier and a Schott GG 14 glass filter, producing
magnitudes close to Johnson's V system, was used.
	The companion (Delta_m = 3 mag., distance 38") was
excluded from the measures.

			[FIGURE 1]

     BS 6604 has been used as the only comparison star.
 The star SAO 103020 has been measured to check the 
 performance of the photometer.

     The phases were calculated with the formula:

Phase = fraction of : (JD hel. - 2440130'7083) x 0'2568053

in which the reciprocal period corresponds to the spectroscopic
period (3.894d) as given by Petrie (1928).
      The lightcurve is shown in the Figure, where the
difference between variable and comparison star has been
plotted against phase. The minima have the same depth of
0.3 magnitude. The eclipses are seen to be separated by half
a period, which is compatible with a circular orbit.
      BS 6611 is HD 161321. The star is No. 491 of Batten's
(1967) recent Catalogue of Spectroscopic binaries. The
V Magnitude at maximum is 6.07.
      More observations are planned to complete the
descending branch at phase .35 and the rising branch at
phase .90.
      The investigation was supported in part by grant
GP 7482 from the National Science Foundation.


Yale University Observatory
New Haven, Connecticut
8 September 1969

                          R. ZISSELL




References:


Batten, A. H., Dom. Astr. Obs. Vol. XIII, 164 (1967). [BIBCODE 1967PDAO...13..119B ]
Petrie, R. M., Dom. Astr. Obs. Vol. IV, 81 (1928). [BIBCODE 1928PDAO....4...81P ]