Central Bureau for Astronomical Telegrams
IAUC 4782: GS 2023+338; OJ 287; P/GUNN; PU Vul
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Circular No. 4782
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
GS 2023+338
F. Makino and the Ginga Team, Institute of Space and
Astronautical Science, Sagamihara, Kanagawa, telex: "A bright x-ray
nova was discovered with the all-sky monitor aboard the Ginga
satellite on May 22 at R.A. = 20 23.3, Decl. = +33 50' (equinox 1950.0).
The corners of the error box are at 20 23.7, +34 02'; 20 24.1,
+33 58'; 20 22.9, +33 40'; and 20 22.5, +33 43'. On May 23 the x-ray
intensity observed with the large area counters varied over the range
0.1-1.2 Crab. The x-ray spectrum is very hard, and the intensity
exhibited erratic variations at various timescales longer than 0.1 s."
OJ 287
L. Takalo, Nordic Optical Telescope, Santa Cruz de la Palma; and
M. Kidger, Instituto de Astrofisica de Canarias, report: "Optical
monitoring by Takalo with a CCD on the 2.5-m Nordic telescope and by
Kidger and J. A. de Diego with the CCD camera on the 1-m Jacobus
Kapteyn Telescope reveals that the BL-Lac object OJ 287 is at an
unprecedentedly faint minimum in B, with multi-color observations on
six nights in April and May revealing variations of more than one
magnitude. At its faintest, on May 16, B = 18.06, B-V = +0.95,
indicating a very much steepened continuum. BVRI photometry on
May 9 gave B = 17.80, B-V = +0.85, V-R = +0.32 and V-I = +0.08. We
strongly recommend spectrophotometry of the object whilst it remains
in this faint state, during which faint underlying spectral features
are likely to be more easily observable."
PERIODIC COMET GUNN
Total visual magnitude estimates: Apr. 15.49 UT, 13.3 (C. S.
Morris, 0.26-m reflector, near Mt. Wilson, CA); 29.38, 12.5
(Morris, Pine Mountain Club, CA); May 4.01, 13.0 (S. Korth,
Dusseldorf, West Germany, 0.36-m reflector); 6.99, 12.8 (Korth).
PU VULPECULAE
Visual magnitude estimates: 1988 Dec. 10.75, 9.9 (S. Baroni,
Milan, Italy); 1989 Jan. 7.78, 10.0 (A. Pereira, Linda-a-Velha,
Portugal); Feb. 17.16, 9.7 (P. Schmeer, Bischmisheim, West Germany);
Mar. 7.18, 9.8 (Schmeer); 28.11, 9.9 (A. Boattini, Florence, Italy);
Apr. 9.09, 9.8 (Schmeer); May 4.04, 9.8 (Schmeer); 22.02, 10.0
(Boattini).
1989 May 24 (4782) Brian G. Marsden
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