Central Bureau for Astronomical Telegrams
IAUC 3487: Cen X-4; HR 1099; NOVALIKE OBJECT IN Vul
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Read IAUC 3488
Circular No. 3487
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
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
CENTAURUS X-4
J. van Paradijs, University of Amsterdam and Massachusetts Institute
of Technology, writes: "Spectroscopic observations of the optical
counterpart of the transient x-ray burst source Cen X-4 (cf.
IAUC 3362) were made with the image-dissector scanner on the ESO 3.6
m telescope during 1979 June 21-26. The spectra (dispersion
17.1 x 10**-6), which cover 400-680 nm, show the following strong
emission lines: Balmer H-alpha through H-delta, He I 447.1, 492.1, 501.6,
587.6 and 667.8 nm and He II 468.6 nm. The approximate visual magnitude
V = 18.2, and B-V = 0.7. The lines are superposed on a continuum
which shows the presence of a low-mass companion star. In
view of a possible nonstellar contribution to the continuum, the
spectral type cannot be determined better than to between K3 and K7.
The implied distance between 1 and 2.5 kpc is in agreement with that
derived from x-ray burst observations. In view of the expected reduced
activity of the system, new optical observations of this
source to confirm and improve the spectral type of the companion
star should be undertaken."
HR 1099
P. A. Feldman and P. M. Smith, Herzberg Institute of Astrophysics,
report the detection of strong radio emission from the RS
CVn-binary HR 1099 with the 46-m telescope of the Algonquin Radio
Observatory. The radio flare, which was first detected on June
14.63 UT, maintained a flux density of ~ 0.2 Jy at 10.48 GHz until
the star set at June 14.85.
NOVALIKE OBJECT IN VULPECULA
J. Hron and H. M. Maitzen, Vienna Observatory, report: "We observed
the novalike object in Vulpecula on May 27d02h00m UT using
the Boller and Chivens spectrograph at the 1.5-m telescope at the
Schoepfl Station. The strongly underexposed spectrogram (30-min exposure
stopped by dawn; dispersion 12.5 x 10**-6) shows a continuum
without recognizable emission. H and K lines of calcium are clearly
visible and of equal strength."
J. Mattei, American Association of Variable Star Observers, provides
the following visual magnitude estimates by AAVSO members:
May 10.3, 10.7 (E. Mayer, Barberton, OH); 15.3, 10.9 (Mayer); 22.0,
11.2 (5. Baroni, Milan, Italy); June 12.2, 12.2 (Mayer).
1980 June 19 (3487) Daniel W. E. Green
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