COMMISSION 27 OF THE I. A. U.
        INFORMATION BULLETIN ON VARIABLE STARS
                    Number 1939

                                  Konkoly Observatory
                                  Budapest
                                  1981 March 23

                                  HU ISSN 0374-0676
 

    1980 ECLIPSE OF EE CEPHEI: LIGHT CURVES AND TIME OF MINIMUM


 The star was observed as follows:

Tizzano observatory: 350 mm reflector f:5.2; photographic observations in U
    (IIaO + UG1, 1mm), B (IIaO + GG385, 2mm), V (IIaD + GG455, 2mm).

Tignano observatory: 400 mm reflector f:5; photoelectric observations with
    a single channel photometer (unrefrigerated 1P21) in UBV (Johnson
    system) and reduction to the International System; photographic
    observations in I (1N + RG695, 2mm).

 BD +55d2690 was used as comparison star for photoelectric observations.
Differential magnitudes in the sense variable star less comparison star in
V are given in Figure 1.

                                [FIGURE 1]
                                [FIGURE 2]


   Observations made during 26 nights, covered better the ascending branch
of the light curve, for we had bad weather conditions during the first part
of the eclipse.
Considering the magnitudes at maximum of EE Cep as
V_max = 10.72; B-V_max= .37; U-B_max= -.18  (Barbier et al. 1973) 
the star reached during the 1980 minimum at least the V_mag= 11.75, and
with Delta(B-V)_min - Delta(B-V)_max= ~.05 (fig.2) is B_min=~12.17
	The computed time of minimum in  V is:
		J.D.2444594.1 +- 0.4d
and the O-C computed on the basis of the elements
Min = J.D.2434346.0+ 2049.53 E (Meinunger 1976)
is
	O-C_1980=0.4d +- 0.4d

                          [FIGURE 3]

  All the photographic magnitudes must be considered provisional and
subject to further revision. Some difficulties in checking the magnitudes
came from the fact that we found the b and c stars (see identification
chart from Meinunger 1975).as variables with an amplitude of v 0.15 mag
in V. Figure 3 report the infrared magnitudes and lightcurve, that are in
the Johnson's system (sequence in NGC 2632=M44). Photographic magnitudes
in V are in the same colour system as for the photoelectric observations,
that must be revised in view of the variability of the b and c stars.
For this provisional reductions we used the average value of the b star.
V photographic light curve is superimposed to the photoelectric one in

                          [FIGURE 4]

Fig. 1: points=photoelectric, triangles=photographic.
 Ten spectra were taken by T. Iijima at the 122 cm telescope of the
Asiago Observatory, with the VI camera and RCA image intensifier. The
dispersion was 60 A/mm at Halpha wavelength. All the spectrograms show the
Balmer series from Halpha to H8, with broad absorption lines. Strong and
broad Halpha and narrow Hbeta emission lines are superimposed. 
Absorption HeI line can be suspected. No applicable spectral variations 
can be revealed during the eclipse. The spectrum is of a Be star of the
B5 III-IV (more possible III) spectral type.

 More detailed and revised results of both spectroscopic and photometric
observations will be published thereafter.


                            L. BALDINELLI, A. FERRI, S. GHEDINI
                            "G. Horn D'Arturo" Observatory
                            C.P. 1630 AD, 40100 Bologna, Italy



References:
Barbier et al.: 1973, Astron. and Astroph., 27, 421. [BIBCODE 1973A&A....27..421B ]
Meinunger, L.: 1975, I.B.V.S., 965.
Meinunger, L.: 1976, M.V.S., 7, 97.