COMMISSION 27 OF THE I. A. U.
      INFORMATION BULLETIN ON VARIABLE STARS
                  NUMBER 235

                                 Konkoly Observatory
                                 Budapest
                                 1967 November 10


                  RY SAGITTARII


Spectroscopic and photometric observations of the RCrB type variable RY Sgr
were begun at the Cassegrain focus of the 74-inch Radcliffe reflector following
the receipt of a letter dated 22 July, from R.P de Kock (Royal Observatory,
Cape) indicating that the star was several magnitudes fainter than usual. The
Figure shows the photoelectric observations made in the UBV system; nights on
which spectra were taken are also shown. The first spectrum (July 25) showed a
rich emission spectrum. CaII, H and K, were the strongest absorption lines in
the underlying continuum which appeared to be quite blue. Subsequently the
continuum became somewhat redder. After August 3 the emission lines weakened
until on August 6 they had almost disappeared. At this stage the absorption
spectrum differed markedly from that at maximum light. A further emission
spectrum appeared around August 30 and thereafter strengthened. The emission
line lambda 3888 identified as HeI in RCrB by Herbig was first seen on
September 11 and subsequently increased in strength until on October 9 it was
equal to CaII, H and K, in emission. A spectrum extending to the red, taken on
October 6 showed the sodium D lines to be very strong in emission. Amongst
other emission lines so far identified are lines of TiII, ScII, FeII and SrII.

                            [FIGURE 1]

 Light curve of RY Sgr. Filled circles, V and (B-V). Open circles (U-B)
   Vertical lines indicate dates on which spectra were obtained.


RY Sgr was found to have a faint companion (V=15.7, (B-V)=+0.7, (U-B)=+0.2) of
which we have found no earlier record. It would be important to know whether
the companion is physical or not.

It is hoped to undertake a detailed analysis of these and subsequent
observations.


Radcliffe Observatory,
Pretoria
1967 October 31
                            P.J. ANDREWS       D.H.P. JONES
                            R.M. CATCHPOLE     T. LLOYD EVANS
                            M.W. FEAST         E.N. WALKER