Central Bureau for Astronomical Telegrams
IAUC 4806: 1989 N 1; Occn OF 28 Sgr BY TITAN; mu Cen; 1987A
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Circular No. 4806
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
1989 N 1
B. A. Smith and S. P. Synnott report that a previously
unknown satellite of Neptune has been discovered in Voyager 2
narrow-angle imaging data. It has been observed in 17 frames
over a time span of 21 days, during which the measurement error
changed from about 1000 km per narrow-angle pixel to about 700 km.
The rms post-fit residuals are about 1 pixel. The orbit is
prograde and appears to be very nearly circular and equatorial.
The period is 1.1223 days, with an uncertainty of 0.0005 days,
and it moves at a mean radial distance of about 117 500 km. The
eccentricity appears to be less than 0.01, and the inclination
is of the order of a degree or less. The satellite would have
been at greatest eastern elongation on June 22d20h26m UT. The
object is about one visual magnitude fainter than Nereid in the
Voyager 2 narrow-angle clear filter.
OCCULTATION OF 28 SAGITTARII BY TITAN
P. Schmeer, Bischmisheim (Long. = -7 03'42", Lat. =
+49 12'52", h = 293 m), West Germany, reports his timings (cf.
IAUC 4801, 4803) of this event obtained with a 0.20-m f/10
reflector (133x): t3 = 43m53s.8, t4 = 44m28s.8, +/- 0.3 s.
mu CENTAURI
J. C. Bhattacharyya, Indian Institute of Astrophysics,
Bangalore, reports: "CCD spectroscopic observations with the
echelle spectrograph at the coude focus of the 1-m reflector at
Vainu Bappu Observatory, obtained by K. K. Ghosh, K. Kuppuswamy,
A. Ramachandran, K. Rajkumar, K. Ravi, and N. Dinakaran, revealed
that the recurrent, transient Be-type star mu Cen developed
H-alpha emission between Apr. 15 (H-alpha asymmetric absorption)
and June 22 (centrally-reversed H-alpha, V/R about 1). By June
24 the H-alpha emission strength had definitely increased."
SUPERNOVA 1987A IN THE LARGE MAGELLANIC CLOUD
Visual magnitude estimates (cf. IAUC 4761): Mar. 13.51 UT,
12.6 (A. Pearce, Perth, W. Australia); 28.50, 12.7 (Pearce);
Apr. 10.39, 12.7 (P. Williams, Heathcote, N.S.W.); 25.48, 12.8
(Pearce); May 5.48, 12.8 (Pearce); June 1.42, 13.0 (Williams);
24.52, 13.2 (Pearce).
1989 July 7 (4806) Daniel W. E. Green
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