Central Bureau for Astronomical Telegrams
IAUC 4425: N Her 1987; P/ENCKE; AM Her
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Circular No. 4425
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
NOVA HERCULIS 1987
H. Dinerstein, H. Coleman, and D. Lester, University of Texas,
Austin, write: "Spectra of Nova Her 1987 in the J, H, and K bands
were obtained on July 13 and 14 at McDonald Observatory, using an
InSb array spectrometer at a resolving power of 100-200. We see
numerous recombination lines of H I and He I, with particularly
strong He I lines at 1.083 and 2.058 microns. A prominent feature at
2.48 microns may be due to [Si VII]; the 1.96-micron [Si VI] line seen in
May (IAUC 4398) falls outside our filter bandpass. Additional
emission features are seen at 1.13, 1.55, and 2.32 microns. Most of
these have been seen in other fast novae, such as Nova Vul 1984 No.
2 (Grasdalen et al., IAUC 4245) and Nova Mus 1983 (Krautter et al.
1984, A.Ap. 137, 307). The feature at 1.55 microns can be plausibly
identified as a blend of N V + O V (10-9) at 1.554 microns and He II at
1.573 microns. The 2.32-micron feature is about 0.2-0.3 microns broad,
as in V1500 Cyg (Grasdalen and Joyce 1976, Nature 259, 187). The
presence of highly-ionized species suggests the development of a hot,
'coronal' region, as seen in several previous fast novae."
Photoelectric photometry by R. Monella, Covo, Italy, with a
0.6-m reflector: July 16.912 UT, V = 12.07, B-V = +0.51, U-B =
-0.96; 18.909, 12.13, +0.49, -1.02; 19.922, 12.26, +0.58, -0.93.
Visual magnitude estimates: June 13.88 UT, 11.8 (A. Boattini,
Piazzano, Italy); 29.97, 11.8 (P. Schmeer, Bischmisheim, West
Germany); July 6.92, 12.1 (S. Korth, Duesseldorf, West Germany).
PERIODIC COMET ENCKE
Total visual magnitude estimates: July 21.25 UT, 5.2 (G. W.
Wolf, Wellington, N.Z., 7x50 binoculars); 24.35, 7.1 (G. Garradd,
Tamworth, N.S.W. 0.15-m reflector); 24.36, 6.9 (R. H. McNaught,
Siding Spring Observatory, 9x63 binoculars).
AM HERCULIS
Visual magnitude estimates: May 17.89 UT, 13.3 (M. Verdenet,
Bourbon-Lancy, France); 22.90, 13.4 (Verdenet); 23.89, 13.7
(Verdenet); 28.92, 13.9 (R. Monella, Covo, Italy); 30.90, 14.0
(Monella); June 1.88, 14.2 (Monella); 15.89, 14.3 (Monella); 17.91,
14.5 (Monella); 18.92, 14.5 (Monella); July 16.91, 13.7 (Monella);
18.91, 13.2 (Monella); 19.92, 13.0 (Monella).
1987 July 24 (4425) Daniel W. E. Green
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