COMMISSION 27 OF THE I. A. U.
         INFORMATION BULLETIN ON VARIABLE STARS
                      Number 1026

                                  Konkoly Observatory
                                  Budapest
                                  1975 August 1

      SPECTROSCOPIC OBSERVATIONS OF NOVA SCUTI 1975


    Nova Scuti 1975 was observed on July 9.0 and 10.0, 1975 with
the 340/500/1375 mm Schmidt telescope of the Hoher List Observatory.
The spectrograms were obtained on Kodak 127-05 plates and have 
dispersions of 645 A/mm at H_gamma and 2200 A/mm at H_alpha. Tracings of the
spectra together with line identifications are shown in Fig. 1. Some
uncertainty in line identification occurred around H_epsilon where it is
possible that the broad blend includes N III 3999,4004.
   An additional Kodak I-N plate taken on July 15.0, 1975 shows
the following emissions in the infrared region: He I 7281; [O II]
7219,30; O I 7772-75; N I 8185-8242; O I 8446,47; N I 8680-8797.
   On the above dates the nova seems to be well within the "4640"
stage - Q6, according to Vorontsov-Velyaminov - and thus about 3
magnitudes below maximum. Though the object was obviously discovered 
after maximum it must still be classified as a very fast nova,
a finding which is supported by the high Balmer line velocities,
averaging -2300 km sec^-1, as obtained from the low-dispersion 
spectrograms. The lower than average velocity of H8 is explained as
resulting predominantly from the He I 3889 absorption, which seems
to be very strong and - as always - indicative of an extended 
atmosphere.
   Lines H_beta to H 10 have two emission peaks. A higher dispersion
spectrogram (88 A/mm) of Nova Scuti obtained on June 26.9, 1975
shows a detailed structure of H_alpha. The violet edge corresponds to a
velocity of -600 km sec^-1, the center to +240 km sec^-1, a strong
red peak to +720 km sec^-1 and the red edge to +1180 km sec^-1. The
observed double structures of H_beta to H 10 on the low-dispersion
spectrograms obtained on July 9.0 and 10.0, 1975 suggest a reversal
of the R/V intensities resulting in a markedly stronger violet peak.
The mean separation of the two peaks of 910 km sec^-1 measured on
the low-dispersion spectrograms is in good agreement with the
above assumption.
   The very hight velocity derived from the absorption 
attributed to N III 4640 may be erroneous. We hope that this 
value as well as the other statements made in this communication
can be verified (or rejected) by other observers on the basis
of high-dispersion spectrograms, since all measurements and 
interpretations made from such low-dispersion spectrograms carry
some degree of uncertainty. Should the results be verified will
this be another indication of the great usefulness of low-dispersion 
spectrograms, a finding which is expected on account of
other work of the Bonn observatory carried out at very low 
dispersions.


                         H.W. DUERBECK
                         W.C. SEITTER
                      Observatorium Hoher List
                       der Universitat Bonn
                      5568 Daun/Eifel, F.R.G.


                     [FIGURE 1]

   Fig. 1. Spectral tracings of Nova Scuti 1975.