Central Bureau for Astronomical Telegrams
IAUC 4398: 1987A; N Sgr 1987; N Her 1987
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Circular No. 4398
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
SUPERNOVA 1987A IN THE LARGE MAGELLANIC CLOUD
M. Hamuy and M. M. Phillips, Cerro Tololo Interamerican
Observatory, telex that nightly Cousins UBVRI photometry with the
CTIO 0.4-m telescope indicates that SN 1987A is now slowly
declining in brightness in all colors. Peak brightness occurred
around May 20 UT, at which time approximate magnitudes were U =
7.12, B = 4.58, V = 2.97, R = 2.28, I = 1.99.
Further visual magnitude estimates by D. A. J. Seargent, The
Entrance, N.S.W.: May 26.36 UT, 2.8; 27.37, 2.8; 28.35, 2.9.
NOVA SAGITTARII 1987
R. H. McNaught, Siding Spring Observatory, revises the end
figures in R.A. (cf. IAUC 4397) to 28s.94 and provides the following
negative observations, mainly from U.K. Schmidt plates: 1974 June
17, J [22.5; 1976 Apr. 28, B [21; 1978 Aug. 27, R [22.5; 1979 July
30, R [20; 1980 July 17, I [18.5; 1987 Apr. 30.64, mpv (hypered
2415 emulsion) [13.4. He also provides the following visual
magnitude estimates: May 24.39 UT, 10.4; 25.39, 10.5; 25.64, 10.8;
26.42, 10.7; 27.48, 11.0; 28.44, 11.0; 28.56, 10.9; 28.75, 10.9.
NOVA HERCULIS 1987
M. A. Greenhouse, Department of Physics and Astronomy,
University of Wyoming, writes: "K-band CVF observations of Nova Her
1987, obtained at the Wyoming Infrared Observatory by M. A. Greenhouse
and C. Woodward on May 9 and by Greenhouse, R. D. Gehrz and
T. J. Jones on May 19, have revealed lines at 1.96 microns and 2.17 microns.
These features are similar to those observed in Nova Vul 1984 No.
2 and Nova Cyg 1975 (cf. Grasdalen et al., IAUC 4245; Grasdalen
and Joyce 1976, Nature 259, 187). We initially interpret the 1.96-
micron feature as the 2P(1/2, 3/2) transition of Si VI and the 2.17-micron
line as Br G. The line-to-continuum ratios for the 1.96-micron and
2.17-micron lines were 1.1 and 1.2, respectively, at the 2.5-percent
resolution of the CVF. The line intensities (in units of 10*-11
erg s-2 cm-1) were 2.66 and 3.33, respectively, on May 9 and 2.36
and 2.24 on May 19. Absolute calibration is +/- 10 percent. In
addition, the following broad-band magnitudes were measured on May
9: J = 9.59 +/- 0.01, H = 8.88 +/- 0.04, K = 7.58 +/- 0.03, L' = 5.99 +/-
0.01, L = 5.49 +/- 0.01, M = 4.99 +/- 0.07."
1987 May 28 (4398) Brian G. Marsden
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