Central Bureau for Astronomical Telegrams
IAUC 4882: 1989r; N Sct 1989
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Circular No. 4882
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 OKAZAKI-LEVY-RUDENKO (1989r)
D. Bockelee-Morvan, G. Bourgois, J. Crovisier, and E. Gerard,
Observatoire de Paris-Meudon, report: "While monitoring the radio
lines of OH in comet 1989r at Nancay, we fortuitously observed the
occultation of the radio source B2 1426+29 by the comet on Oct. 13.54
UT. The point radio source (which has a flux of about 0.6 Jy at
18 cm) was then 1' from the comet nucleus (corresponding to a
projected distance of 60 000 km in the comet frame). During the
occultation, the peak flux of the 1667-MHz OH line is 85 +/- 12 mJy
and the half-power width is 1.45 +/- 0.25 km/s. The line has
increased in intensity and decreased in width, compared to the average
line observed before and after the occultation (34 +/- 5 mJy and
2.22 +/- 0.45 km/s, respectively, for the average of Oct. 11.5,
12.5, 14.5, and 15.5). This was expected from the hypothesis of
the OH maser amplification of the background. In order to check
that part of the flux increase on Oct. 13 is not due to an outburst,
we would greatly appreciate any information on the comet activity
at that time. The average OH production rate around the occultation
was 5 x 10E28 sE-1 (using the parameters of 'model 1986a' given
by Gerard et al. 1987, A.Ap. 187, 455)."
G. Mengoli and F. Muzzi, Bologna, Italy, report the following
tail lengths recorded with a 0.15-m Schmidt camera (+ 3M CRT7
x-ray film): Sept. 30.812 UT, 0.78 deg in p.a. 53 deg; Oct. 1.793,
2.00 deg in p.a. 51 deg; Oct. 4.791, 1.48 deg in p.a. 49 deg.
Total visual magnitude estimates (cf. IAUC 4876): Oct. 14.02
UT, 7.7 (G. Kronk, Troy, IL, 0.33-m reflector); 17.74, 6.5 (R.
Haver, Tolfa, Italy, 15x80 binoculars; 0.5 deg tail in p.a. 25 deg);
18.81, 6.5 (A. Pereira, Cabo da Roca, Portugal, 9x34 binoculars);
19.11, 6.9 (C. S. Morris, Whitaker Peak, CA, 10x50 binoculars);
20.08, 6.6 (R. A. Keen, Mt. Thorodin, CO, 8x40 binoculars); 23.00,
6.9 (G. R. Chester, Rixeyville, VA, 7x50 binoculars).
NOVA SCUTI 1989
Visual magnitude estimates (cf. IAUC 4873): Oct. 13.19 UT, 11.2
(P. Walker, Vergennes, VT); 14.04, 11.3 (G. Kronk, Troy, IL); 15.74,
10.3 (P. Schmeer, Bischmisheim, West Germany); 16.77, 10.0 (Schmeer);
18.81, 9.4 (A. Pereira, Cabo da Roca, Portugal); 19.73, 9.8 (E.
Schweitzer, Strasbourg, France); 19.76, 10.1 (A. Boattini, San
Vincenzo, Italy); 21.78, 11.1 (Schmeer); 22.74, 10.7 (Schweitzer).
1989 October 23 (4882) Daniel W. E. Green
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