COMMISSION 27 OF THE I.A.U.
               INFORMATION BULLETIN ON VARIABLE STARS
                            Number 1492

                                                      Konkoly Observatory
                                                      Budapest
                                                      1978 September 20

           THE UV SPECTRUM OF HR 8752

In recent years the super-luminous star HR 8752 (HD 217476
currently G5 O-Ia) has been undergoing a continuous change in
spectral type (see Lambert and Luck, 1978) and has been detected 
as a radio source by Smolinski et al. (1977). We have 
observed it with the International Ultraviolet Explorer as part
of a programme to study variable and emission-line stars.
Spectra were obtained at low resolution (6A) with both spectrographs: 
in the short wavelength region (1150A - 2000A) on 1978
July 24 and in the long wavelength region (1800A - 3000A) on
1978 August 1.
   The spectrum recovered was that of an early type star. From
the Si IV (1398)/C IV (1549) ratio we estimate the spectral
type to be about B1 using the calibration of Molnar (1975); from
the level of the exposure and the duration of the exposure, we
deduce an apparent visual magnitude (after allowance for reddening) 
of about +11. If the absolute magnitude of the G-type star
is taken as -9, this suggests that the hot companion is close
to the main sequence. It seems probable to us that this early
type companion is responsible for the excitation of the shell
which gives rise to the forbidden [N II] emission lines (Sargent,
1965) and the free-free radio emission.
   A more detailed account will be prepared and submitted to
Astronomy and Astrophysics in due course.


                     D.J. STICKLAND

UK IUE Project, ESA Satellite Tracking Station, Apartado 59065
                      Madrid, Spain

  F. BEECKMANS, P. BENVENUTI, J. CLAVEL, A. HECK, F. MACCHETTO,
                M.V. PENSTON, P.L. SELVELLI

    Astronomy Division, ESTEC, ESA Satellite Tracking Station,
               Apartado 54065, Madrid, Spain



References:

Lambert, D.L., Luck, R.E., 1978, Mon. Not. R. Astron. Soc., 184, 405 [BIBCODE 1978MNRAS.184..405L ]
Molnar, M., 1975, Astrophys. J., 200, 106 [BIBCODE 1975ApJ...200..106M ]
Sargent, W.L.W., 1965, Observatory, 85, 33 [BIBCODE 1965Obs....85...33S ]
Smolinski, J., Feldman, P.A., Higgs, L.A., 1977, Astron, Astrophys., 60, 277 [BIBCODE 1977A&A....60..277S ]


Editor's note: This paper came to the editor's hand on September 
20, 1978. Its release, however, had to be delayed until the
appearance of the commissioning phase papers.