Central Bureau for Astronomical Telegrams
IAUC 4582: N Oph 1988; 1987g; 1987s
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Circular No. 4582
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
TWX 710-320-6842 ASTROGRAM CAM Telephone 617-495-7244/7440/7444
MARSDEN or GREEN@CFA.BITNET MARSDEN or GREEN@CFAPS2.SPAN
NOVA OPHIUCHI 1988
H. Kosai, Tokyo Astronomical Observatory, provides the following
accurate position, measured by him from the Apr. 14 film by M. Wakuda:
R. A. = 17h08m50s.84, Decl. = -29d33'58".4 (equinox 1950.0).
R. H. McNaught, Siding Spring Observatory, also provides an
accurate position (uncertainty 0".6), from the mean of two films
exposed on Apr. 18 with the Uppsala Southern Schmidt: end figures
50s.81, 57".7. He suggests that the prenova is a blue star of mag
approximately 20.5 and has measured a position (uncertainty 0".5) from
the U.K. Schmidt J survey film of 1976 May 31: end figures 50s.86,
58".2. He adds that the prenova is much brighter on B and J plates
than on an I plate; on the J film it is flanked by stars of similar
brightness, 3" north and 3" south. Patrol photographs by McNaught
(T-Max 400, 85-mm lens) yield the following magnitudes: Apr. 12.63 UT,
10.0; 13.65, 10.1; 14.74, 10.0; 15.62, 10.0.
Visual magnitude estimates: Apr. 18.56 UT, 10.1 (M. Morel, Rankin
Park, N.S.W.); 18.58, 10.0 (McNaught).
PERIODIC COMET TEMPEL 2 (1987g)
D. Jewitt and J. Luu, Massachusetts Institite of Technology,
report: "We have observed P/Tempel 2 using the 1.3-m telescope and
MASCOT CCD at the McGraW-Hill Observatory, Kitt Peak. From a
preliminary analysis of photometry obtained during Apr. 9-15 we find
that the mean Mould R magnitude is m = 17.3 +/- 0.1. The comet's
image is stellar and exhibits cyclic brightness variations of
approximate period 9 hr (two maxima per period) and peak-to-peak range
0.7 mag. These observations are compatible with the direct detection
of the nucleus of P/Tempel 2. An aspherical (2:1 axis ratio) nucleus
is implied. The photometric range is twice the range measured by us
in 1987 April, indicating that the sub-earth latitude is approaching
the nuclear equator. The inferred mean absolute red magnitude of the
nucleus is m(1,1,0) = 14.3 +/- 0.2, about 1 mag fainter than the
nucleus of P/Halley."
COMET BRADFIELD (1987s)
Total visual magnitude estimates: Mar. 18.80 UT, 10.1 (M. V. Zanotta,
Milan, Italy, 0.30-m reflector); 20.18, 9.9 (A. Hale, Las Cruces, NM,
0.41-m reflector); Apr. 5.15, 10.6 (Hale; extremely diffuse); 6.13,
11.1 (E. A. Jacobson, Evansville, MN, 0.25-m reflector); 9.17, 13.1
(D. Levy, Tucson, AZ, Catalina 1.54-m reflector).
1988 April 19 (4582) Brian G. Marsden
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