Central Bureau for Astronomical Telegrams
IAUC 5566: N Sgr 1992 No. 2; SATURN; N Pup 1991
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Circular No. 5566
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@CFA or GREEN@CFA (.SPAN, .BITNET or .HARVARD.EDU)
NOVA SAGITTARII 1992 No. 2
R. H. McNaught, Anglo-Australian Observatory, reports his
measurement of the nova's position from a V CCD image obtained by
D. F. Koehne (Mt. Stromlo Observatory) using the Siding Spring
1.0-m reflector on July 23.6 UT: R.A. = 18h20m17s.29, Decl. =
-28 23'35".6 (equinox 1950.0); V about 9.1.
Photometry by A. C. Gilmore, Mt. John University Observatory:
July 18.53 UT, V = 9.12, B-V = +0.29, U-B = -0.67, V-R = +0.86, V-I
= +1.18 (non-photometric conditions); July 20.60, 9.07 +/- 0.03,
+0.28 +/- 0.01, -0.68 +/- 0.02, +0.78 +/- 0.01, +1.05 +/- 0.04.
SATURN
T. R. Geballe, Joint Astronomy Centre; and M.-F. Jagod and T.
Oka, University of Chicago, report: "We have detected H3+ in the
polar regions of Saturn. Spectra showing three lines of H3+ were
obtained on July 19 and 20 UT at the U.K. Infrared Telescope with
the facility instrument, CGS4, using a resolving power of about
17 000. The 1".1-wide slit of CGS4 was aligned along the polar
axis of Saturn, typically producing nine spectra at different
positions on the disk of the planet. The detected lines are the
rR(3,3) at 2830 cmE-1 (3.53 microns) and the pR(1,1) and rR(1,0)
doublet at 2726 cmE-1 (3.67 microns). The last of these is the
brightest, with a strength of about 5 x 10E-18 W mE-2 in a 1".1 x
2".2 aperture on the planet at each of the poles. The line
intensities below the north pole decrease markedly. The behavior just
above the south pole is uncertain, due to contamination by radiation
from the rings. The intensity ratio of the doublet, which
consists of one ortho and one para line, is as expected for H3+ in
thermal equilibrium at several hundred degrees Kelvin. As observed
by CGS4, the highest surface brightnesses of the fundamental
band H3+ lines from Saturn are a factor of a few lower than
those from Uranus, and they are more than two orders of magnitude
less than those from Jupiter."
NOVA PUPPIS 1991
Photometry by Gilmore (cf. IAUC 5552): July 18.30 UT, V =
11.65 +/- 0.01, B-V = -0.10 +/- 0.01, U-B = -1.10 +/- 0.03, V-R =
+0.98 +/- 0.03, V-I = +0.70 +/- 0.08.
1992 July 23 (5566) Daniel W. E. Green
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