COMMISSION 27 OF THE I. A. U.
         INFORMATION BULLETIN ON VARIABLE STARS
                     Number 1714

                                  Konkoly Observatory
                                  Budapest
                                  1979 December 10


      THE ERUPTIVE VARIABLE IN SCORPIUS: A SYMBIOTIC STAR


Sanduleak, Stephenson and MacConnell (1978) have reported the discovery of an
"eruptive variable" in Scorpius (alpha 17h40m32.6s delta -36d02'07"
(1950)). They found it to show a strong emission spectrum (Balmer lines,
[OIII] lines and the 4640-68 A blend) and to be about 14th magnitude.

The object was observed with the infrared photometer on the 0.75m telescope at
the SAAO at Sutherland on 1978 July 10 with the following results:

J(1.2 micron)=10.05+-.08   H(1.6 micron)=8.79+-.05   K(2.2 micron)=8.28+-.04

The infrared colours show that a cool component is present in this object. The
photometry is consistent with the presence of a late M giant having an A_v of
about 3 magnitudes (using intrinsic colours from Lee 1970). Since for such a
star M_K is about -7, the distance of the system is about 10 kpc. The object
is thus best interpreted as a symbiotic system in the general region of the
nuclear bulge of our Galaxy. The fact that the object had not apparently been
detected in previous objective prism surveys suggests that it may have been
unusually bright at the time of the work of Sanduleak et al.


B.S. CARTER
M.W. FEAST
S.A. Astronomical Observatory, Cape
PO Box 9, Observatory
7935 South Africa

References:

Lee, T.A., 1970. Ap, J. 162, 217. [BIBCODE 1970ApJ...162..217L ]
Sanduleak. N., Stephenson L.D., and MacConnell, D.J., 1978, I.B.V.S. No. 1376