COMMISSION 27 OF THE I. A. U.
	  INFORMATION BULLETIN ON VARIABLE STARS
		      Number 2656


				    Konkoly Observatory
				    Budapest
				    21 January 1985

				    HU ISSN 0374 - 0676


	     TWO-COLOUR PHOTOELECTRIC LIGHT CURVES
	       OF THE ECLIPSING BINARY V367 Cyg


  The light-variability of V367 Cyg, which was first suspected by Humason,
was confirmed by Christie (1932). Here I present the latest light curves of the
system.

  The eclipsing binary V367 Cyg was observed in B and V colours at the Ege
University Observatory from August 22 to December 9, 1984. The observations
were made with the 48 cm cassegrain telescope equipped with an unrefrigerated
EMI 9781A photomultiplier. BD + 38d4239 was used as comparison star. A total
of 250 observations in each colour were obtained on 23 nights. The phases of the
observations have been computed from the ephemeris given by Abt (1954):

     Primary minimum = JD 2434 266.296+18.5972d E.

  The differential observations in the sense comparison minus variable were
corrected for atmospheric extinction and the times of individual observations
were reduced to the Sun's centre. Figure 1 and Figure 2 show the B and V light
curves of V367 Cyg, respectively.

     It can be seen from Figure 1 and Figure 2 :

a) that the maxima preceding primary minima are brighter than the maxima following
primary minima (this feature is well distinguished especially in the B light
curve rather than the V light curve)

b) that the ascending branches of the light curves are slightly steeper than
the descending branches, particularly in the secondary minima.

  These two characteristics of the present light curves of the system are in
well conformity with those of Christie, Kukarkin and Parenago, Filin, Gaposchkin,
and of Heiser (see Heiser, 1962).
  Normalizing these new light curves to 0.0 mag at phase 0.75 a further
approximate comparison with the earlier ones can be made. Doing so, it can be
easily seen that both the primary and the secondary minima fall between those
of Filin and of Gaposchkin (see Heiser, 1962). This, once again proves the
fact that the depths of the minima of V367 Cyg varies with time.

                          [FIGURE 1]

           Figure 1: The B light curve of V367 Cyg in 1984.

                          [FIGURE 2]

           Figure 2: The V light curve of V367 Cyg in 1984.

                          [FIGURE 3]

           Figure 3: The (B-V) curve of V367 Cyg in 1984.

 The colours of V367 Cyg as a function of phase, shown in Figure 3, have some
slight variations of small amplitude. Considering the sudden reddening between
phases 0.95 and 0.00, and the abrupt variation towards blue near the phase
0.54 which is coincident with the secondary minimum of the light curve, it is
possible to say that the primary star is the hotter star.
 It should be noted here that computation of a new time of primary minimum
was especially avoided since the quantity of the observations at the mid-
primary had been considered insufficient to permit such an attempt. The
photoelectric observations of V367 Cyg will be continued in the coming observing
season.





			       M. CAN AKAN

			       Yali Caddesi
			       No: 294 Kat: 6/11
			       Karsiyaka Izmir
			       Turkey


References:

Abt, H.A., 1954, Pub.A.S.P., 66, 1971. [BIBCODE 1954PASP...66..171A ]
Christie, W.H., 1932, Pub.A.S.P., 44, 125. [BIBCODE 1932PASP...44..125C ]
Heiser, A.M., 1962, Ap.J., 135, 78. [BIBCODE 1962ApJ...135...78H ]