COMMISSION 27 OF THE I. A. U.
          INFORMATION BULLETIN ON VARIABLE STARS
                        Number 3107



                                     Konkoly Observatory
                                     Budapest
                                     3 November 1987

                                     HU ISSN 0374-0676



         1987 AMPLITUDE CHANGES OF II Peg LIGHT CURVE


  The RS CVn type star II Peg (HD 224085, BD +27 4642) has been photometrically 
observed since 1986 using a 0.4m telescope with a solid-state photometer 
at Mollet Observatory, Barcelona (Spain).
  From 3 to 11 December 1986 we made differential photometric measurements
with the B and V filters using HR 8997 and BD +28 4667 as comparison star and
check star, respectively. We continued these observations in 1987
with BVRI filters (Johnson system) using HD 223332 as comparison star by
checking it with HR 8997 on several nights.
  The resulting BVRI light curves obtained during the period 12 September -
18 October 1987, are plotted in Figure 1. The orbital phases were calculated
according to the ephemeris of Vogt (1981):

             HJD = 2443033.47 + 6.72422d E


                             [FIGURE 1]


Regarding Byrne (1986), Cutispoto et al, (1987), Mekkaden (1987), and our
own observations (December 1986, unpublished information) which match the 
observations of Cutispoto et al., the current V light curve shows an important
amplitude decrease due to a lower maximum and an upper minimum. That is, a
variation of the amplitude in V from 0.5 to 0.15 magnitudes has occurred
within only a few months.
   Such a fast change, as the present one, has not been noticed in the past
with the exception, perhaps, in 1978 (Poe and Eaton, 1985), although a 
complete light curve of II Peg was not available in that year.


                      J.A. CANO, R. CASAS, C. GALLART, J.M. GOMEZ,
                            E. JARIOD, M. PERACAULA

                           Grup d'Estudis Astronomics
                              Apartat 9481

                             08080 Barcelona

                                Spain





References :

Byrne, B.P.: 1986, Inf. Bull. Var. Stars, No, 2951
Cutispoto, G., Leto, G., Pagano, I., Santagati, G., Ventura, R.: 1987,
        Inf. Bull. Var. Stars, No. 3034
Mekkaden, M.V.: 1987, Inf. Bull. Var. Stars, No. 3043
Poe, C.M., Eaton, J.A.: 1985, Astrophys. J. 289, 649. [BIBCODE 1985ApJ...289..644P ]
Vogt, S.S.: 1981, Astrophys.J. 247, 975 [BIBCODE 1981ApJ...247..975V ]