Central Bureau for Astronomical Telegrams

Central Bureau for Astronomical Telegrams -- Image credits

IAUC 5653: N LMC 1992; 1992t

The following International Astronomical Union Circular may be linked-to from your own Web pages, but must not otherwise be redistributed (see these notes on the conditions under which circulars are made available on our WWW site).

Read IAUC 5652 SEARCH Read IAUC 5654

View IAUC 5653 in .dvi or .ps format.
IAUC number 

                                                  Circular No. 5653
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 IN THE LARGE MAGELLANIC CLOUD 1992
     M. Della Valle and U. Kaeufl, European Southern Observatory,
report:  "Spectrograms (range 400-800 nm, resolution about 1 nm)
obtained on Nov. 13.35 UT with the New Technology Telescope (+
EMMI) at La Silla, confirm this object (cf. IAUC 5651) to be a nova
at maximum.  Preliminary analysis of the spectra reveals a very
narrow H-alpha emission line, flanked by a blue-shifted P-Cyg
absorption superimposed on a strong continuum.  The expansion velocity
derived from the minimum of the P-Cyg absorption is about 900
km/s.  Emission lines of O I [mult. 20] and Ca I [mult. 30] (
possibly blended with O I [mult. 38]), and Na I D are also visible.
Iron lines of Fe II [mult. 42] are still visible in absorption."


PERIODIC COMET SWIFT-TUTTLE (1992t)
     G. Paubert, Institut de Radio Astronomie Millimetrique; P.
Colom, D. Bockelee-Morvan, G. Bourgois, J. Crovisier, E. Gerard,
and L. Jorda, Observatoire de Paris-Meudon; and D. Despois,
Observatoire de Bordeaux, report:  "We observed P/Swift-Tuttle with the
IRAM 30-m millimeter telescope.  On Nov. 11-12, HCN was detected
through its J = 1-0 line at 89 GHz.  The line area summed over the
3 hyperfine components is 0.27 +/- 0.02 K km sE-1, corresponding to
a production rate on the order of 1.5 x 10E26 sE-1.  CH3OH was
detected on Nov. 11 through several transitions around 145 GHz; the
most intense, at 145.103 GHz, has an area of 0.16 +/- 0.025 K km
sE-1.  We evaluate the CH3OH production rate as about 2 x 10E27
sE-1.  All lines are blueshifted by 0.5-0.7 km sE-1.  The monitoring
of the OH 18-cm lines at the Nancay radio telescope shows important
day-to-day variations.  From the average of the Nov. 10-12
observations, the OH production rate is about 2.5 x 10E29 sE-1.
The 18-cm lines are consistently blueshifted by 0.8 +/- 0.1 km sE-1.
The strong line blueshifts observed testify to the important
anisotropic outgassing and nongravitational forces in this comet."
     Further selected total visual magnitude estimates:  Nov. 7.08
UT, 5.3 (P. Collins, Boulder, CO, 10x50 binoculars); 8.71, 5.5 (K.
Sarneczky, Budapest, Hungary, 20x60 binoculars); 10.09, 5.4 (C.
Spratt, Victoria, BC, 7x50 binoculars); 10.76, 5.3 (H. Luthen,
Hamburg, Germany, 10x50 binoculars); 13.09, 5.3 (C. S. Morris,
Whitaker Peak, CA, 10x50 binoculars; 2.0-deg tail); 13.98, 5.3
(D. W. E. Green, Cambridge, MA, 12x50 binoculars).


1992 November 14               (5653)            Daniel W. E. Green

Read IAUC 5652 SEARCH Read IAUC 5654

View IAUC 5653 in .dvi or .ps format.

Our Web policy. Index to the CBAT/MPC/ICQ pages.

Valid HTML 4.01!