Central Bureau for Astronomical Telegrams
IAUC 5354: 1991y; V1017 Sgr; MWC 560
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Circular No. 5354
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
Telephone 617-495-7244/7440/7444 (for emergency use only)
TWX 710-320-6842 ASTROGRAM CAM EASYLINK 62794505
MARSDEN or GREEN@CFA.BITNET MARSDEN or GREEN@CFAPS2.SPAN
COMET McNAUGHT-HUGHES (1991y)
Robert H. McNaught reports his discovery of a comet on an R
plate taken by S. M. Hughes with the U.K. Schmidt Telescope at
Siding Spring. The discovery plate shows the comet as strongly
condensed, with a diffuse 2' tail in p.a. 250 deg. The following
measurements by McNaught include his Oct. 1 observation from an Uppsala
Southern Schmidt telescope film:
1991 UT R.A. (1950) Decl. m1 Observer
Sept.30.51236 23 09 59.79 -18 49 21.1 16.5 Hughes
30.55403 23 09 58.67 -18 49 20.4 "
Oct. 1.45787 23 09 36.13 -18 48 49.9 McNaught
V1017 SAGITTARII
J. A. Mattei, AAVSO, reports that this symbiotic variable appears
to be starting an outburst. Previous known outbursts occurred
in 1901, 1919, and 1973, when the star reached visual magnitudes
10.7, 7.2, and about 10, respectively. During 1990, V1017 Sgr was
in the range 14 < mv < 15. D. Overbeek, Edenvale, R.S.A., reports
that the object was at mv = 13.3-13.5 during Aug. 3-Sept. 17.
Further visual magnitude estimates: July 7.7 UT, 13.5 (T. Cooper,
Benoni, R.S.A.); 19.7, 13.5 (Overbeek); Sept. 13.1, [13.0 (J. E.
Bortle, Stormville, NY); 28.033, 12.6 (Bortle); 29.010, 12.6
(Bortle); 29.104, 12.6 (D. York, Albuquerque, NM); 29.74, 13.1
(Overbeek); 30.015, 12.6 (Bortle); 30.104, 12.5 (York); 30.74, 12.8
(Overbeek).
MWC 560
T. Tomov and D. Kolev, National Astronomical Observatory,
Rozhen, Bulgaria, telex: "We obtained spectrograms (resolution 18
A/mm) of MWC 560 on Sept. 27, 28, 29 and 30 in the region 360-490
nm. After the relatively 'quiet' state during late 1990-early 1991,
the activity of the star has again risen. The most remarkable
features in our spectra are the strong Balmer absorption components
blue-shifted by about -1800 km/s, with full widths at the continuum
level being 700-900 km/s. Ca II K and He I lines show absorptions
with the same velocity. In the Sept. 28 and 30 spectra, there were
additional absorption components blue-shifted by about -350 km/s,
-160 km/s, and -450 km/s. Also present were emission lines of H-
beta to H-delta and the singly-ionized metals, appearing exactly as
during 1990 Jan.-Apr. The radial velocities of the metallic
emission lines remain at about +40 km/s."
1991 October 1 (5354) Daniel W. E. Green
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