Central Bureau for Astronomical Telegrams
IAUC 4830: NEPTUNE RING ARCS; 1989o; V827 Her = N Her 1987
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Circular No. 4830
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
NEPTUNE RING ARCS
The Voyager Imaging Science Team has found two Neptune ring
arcs, designated 1989 N1A and 1989 N2A, and apparently associated
with the new satellites 1989 N4 and 1989 N3, respectively. The
first arc, of length about 45 deg, was seen azimuthally
centered on and just outside 1989 N4. The second arc, of length
about 10 deg, appeared to trail 1989 N3 by about 90 deg.
These observations were made on Aug. 11.167 UT.
PERIODIC COMET BRORSEN-METCALF (1989o)
T. Y. Brooke and A. T. Tokunaga, Institute for Astronomy,
University of Hawaii, report the detection of the 3.4- and 2.8-micron
emission features in this comet by J. S. Carr, K. Sellgren,
L. J. Allamandola, S. A. Sandford, and M. Tapia, using the NASA
Infrared Telescope Facility, Mauna Kea, on Aug. 6.6 and 7.6 UT.
The 3.4-micron feature appears to be similar in shape to that
seen in comets P/Halley, Wilson (1987 VII), and Bradfield (1987 XXIX).
G. Mengoli and F. Muzzi, Bologna, Italy, report that
a 0.15-m Schmidt camera photograph taken Aug. 5.1 UT shows a faint
1.3-deg tail in p.a. 263 deg.
N. P. Meredith, D. Rees, and J. Young, Table Mountain
Observatory, telex that observations on Aug. 9.4 and 11.4 UT
with the 0.60-m telescope (+ 1.0-nm FWHM bandwidth filters) show
CO+ and H2O+ tail emission, with the tail extending beyond 1.5
deg in length. The coma diameter in CN is greater than 1.0 deg.
Total visual magnitude estimates (cf. IAUC 4827): Aug. 6.2 UT,
7.0 (M. Kidger, Tenerife, Canary Islands, 12x50 binoculars); 7.48,
6.5 (C. S. Morris, La Canada, CA, 10x50 binoculars); 8.06, 6.2 (R.
Haver, Monte Livata, Italy, naked eye); 9.35, 6.6 (J. E. Bortle,
Stormville, NY, 10x50 binoculars); 10.28, 5.8 (C. Spratt, Victoria,
BC, 11x80 binoculars; comet low; aurora); 11.47, 6.1 (Morris).
V827 HERCULIS = NOVA HERCULIS 1987
Visual magnitude estimates (cf. IAUC 4686): 1988 Dec. 8.71
UT, [15.2 (A. Boattini, Piazzano, Italy); 1989 June 9.95, 15.4
(Boattini); 14.04, [15.8 (M. Verdenet, Bourbon-Lancy, France);
30.90, 15.5 (Boattini).
1989 August 11 (4830) Daniel W. E. Green
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