COMMISSION 27 OF THE I. A. U.
	  INFORMATION BULLETIN ON VARIABLE STARS
	               Number 1075

                                 Konkoly Observatory
                                 Budapest
                                 1975 December 15

         Halpha SPECTROSCOPY OF THE
        RS CVn STAR UX Ari (HD 21242)

   Following the report (Weiler 1975a) of variations in Halpha
and the Ca II H and K lines in several RS CVn type systems, we have
begun observations of the Halpha region in UX Ari.
   Nine spectrograms (dispersion 36 A/mm) have been obtained of
the region lambdalambda5700-6800 with the Ritter Observatory 1m reflector and
Cassegrain spectrograph. Halpha is in emission on all our spectrograms, 
but the intensity is highly variable. Our preliminary
results are summarized in the table below. The phases have been
computed from the orbital elements of Carlos and Popper (1971).

DATE (UT)         HJD       PHASE   EW (Halpha)
  1975          2440000+            (A)
 5 Oct.        2690.893     0.199    0.54
16 Oct.        2701.812     0.895    0.36
 6 Nov.        2722.746     0.147    1.53
11 Nov.        2727.699     0.916    0.54
11 Nov.        2727.788     0.930    0.57
17 Nov.        2733.600     0.833    0.86
18 Nov.        2734.664     0.998    0.19
20 Nov.        2736.649     0.306    0.95
20 Nov.        2736.770     0.325    0.92


   The equivalent width of the Halpha emission varies by nearly a
factor of ten over the interval of our observations. It is too early
to tell if this variability is strictly phase dependent; conceivably
some part of it could be erratic and connected with the radio 
outbursts seen in this star (Gibson, Hjellming, and Owen 1975). There
is the suggestion, however, that emission maximum occurs near phase
0.15, substantially in agreement with Weiler's (1975b) spectrophotometry.

   Radial velocity measures show the cooler (K0 IV) component to
be the origin of the Halpha emission. The hotter component (G5V) does
have absorption lines visible in the red, though they are difficult
to resolve at our dispersion. Three spectra near phase 0.9 show
the Halpha absorption of the G5 star to the red of the emission, mimicking
an inverse P-Cygni profile. Some of the equivalent width variations
may be due to this spectral overlapping.
   Additional spectroscopy of UX Ari and other RS CVn systems is
in progress.

   Partial support for this research was provided by a Faculty
Research Award from The University of Toledo.



                KATHY MULLIGAN
                BERNARD W. BOPP
                Ritter Observatory
                The University of Toledo
                Toledo, OH 43606
                USA



References:
Carlos, R. C., and Popper, D. M. 1971, P.A.S.P., 83, 504. [BIBCODE 1971PASP...83..504C ]
Gibson, D. M., Hjellming, R. M., and Owen, F. N. 1975, Ap.J. (Lett).
   200, L99. [BIBCODE 1975ApJ...200L..99G ]
Weiler, E. J., 1975a, B.A.A.S., 7, 267. [BIBCODE 1975BAAS....7..267W ]
Weiler, E. J., 1975b, I.B.V.S. 1014.