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IAUC 3313: WZ Sge; OPTICAL CANDIDATE FOR LMC X-2; 1977n; 1978o

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                                                  Circular No. 3313
Central Bureau for Astronomical Telegrams
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
TWX 710-320-6842 ASTROGRAM CAM     Telephone 617-864-5758

     N. Brosch and E. M. Leibowitz, Wise Observatory, communicate:
"Image-tube spectrograms (dispersion 100 A/mm) obtained on Dec.
1.75 UT (three plates) show H5, H6, H7 and H-beta in absorption on a
very intense blue continuum; wide emission (dlambda ~ 70 A) around 4640 A;
and weak H in emission with dLambda ~ 25 A.  On Dec. 2.71 UT (four
plates) the blue continuum was relatively weaker than the previous
night with respect to the red; H6 to H9 appeared in absorption;
there was a narrow absorption at 4668 A on top of a wide emission;
H-beta appeared in emission; there was a saddle-shaped H-alpha emission with
a central depletion at 6565 A."

     M. Pakull, European Southern Observatory, reports: "Inspection
of UBV plates taken with the 100-cm Schmidt telescope reveals that
the brighter (B ~ 18.5) of the visible pair in the southern part of
the HEAO-1 error box for LMC X-2 (Johnston et al. 1978, Astrophys.
J. 225, L59) is relatively bright in the ultraviolet.  From available
U plates the star is found to be variable by about 0.5 magnitude,
and this is confirmed on V and B plates.  The implied ratio
of x-ray to optical luminosity of 500, together with the relative
faintness of the star, suggests a low- or medium-mass system with
considerable heating effect in the optical component, similar to
Sco X-1 or Her X-1.  The candidate lies well within the recently
refined HEAO-1 position (Johnston et al. in preparation).  Two
other stars, 12" and 22" southeast of the center of the former
HEAO-1 position, also appear bright in the ultraviolet.  No apparent
variability has been detected, however, in either of them, and
since their positions are outside the error boxes they appear to be
less likely candidates for LMC X-2."

     J. Bortle, Brooks Observatory, informs us that he just suspected
this comet at m1 = 13.4 on Nov. 29.39 UT (32-cm reflector).

     Corrigendum.  On IAUC 3287, the declination for the second
observation should read -20o37'08".1, not -20o37'01".8.

1978 December 11               (3313)              Brian G. Marsden

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