Central Bureau for Astronomical Telegrams
IAUC 5020: 1990c; 1989c1; 3C 345
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Circular No. 5020
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 LEVY (1990c)
The following precise positions have been reported:
1990 UT R.A. (1950) Decl. m1 Observer
May 22.47222 23 55 33.53 +27 37 47.0 Helin
23.03779 23 55 52.16 +27 39 32.6 11 Mrkos
23.04306 23 55 52.44 +27 39 33.7 "
E. Helin, B. Roman, and K. Lawrence (Palomar). 0.46-m Schmidt films.
Measured by Roman.
A. Mrkos (Klet).
COMET AUSTIN (1989c1)
D. Bockelee-Morvan, Observatoire de Paris, Meudon; D. Despois,
Observatoire de Bordeaux; G. Paubert, Institut de Radio Astronomie
Millimetrique (IRAM); P. Colom, Centro Astronomico de Yebes; and J.
Crovisier, Observatoire de Paris, Meudon, report: "During observations
of comet Austin with the IRAM 30-m millimeter telescope on
May 21, HCN was detected through its J(1-0) transition at 89 GHz.
The line area (sum of the three hyperfine components) is 0.21 +/-
0.04 K km sE-1, and the derived production rate is about 4 x 10E25
sE-1. H2CO was firmly detected through its 3(1,2)-2(1,1) transition
at 226 GHz. The line area is 0.28 +/- 0.04 K km sE-1 and the
linewidth is 1.7 km sE-1. We tentatively derive a formaldehyde
production rate of the order of 5 x 10E25 sE-1, assuming a coma
temperature of 70 K and that H2CO is coming from the nucleus.
However, observations of the line at offset positions suggest that the
source of H2CO might be extended."
3C 345
L. Takalo, Turku University Observatory; and M. Kidger, Instituto
de Astrofisica de Canarias, report: "We obtained CCD photometry
of 3C 345 that shows that, after a partial recovery of brightness
from the 1989 minimum, a renewed and very fast fade to unprecedentedly
low levels has resumed. Observations with a GEC-type CCD on the
2.5-m Nordic Optical Telescope at La Palma yield the following
measurements: May 12.2 UT, B = 17.08 +/- 0.02; May 21.2, B = 17.87 +/-
0.03; May 22.2, B = 18.66 +/- 0.06, B-V = +1.12, V-R = +0.09."
1990 May 23 (5020) Daniel W. E. Green
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