Central Bureau for Astronomical Telegrams
IAUC 5021: V3890 Sgr; EXTRAGALACTIC SiO
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Read IAUC 5022
Circular No. 5021
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
V3890 SAGITTARII
R. Gonzalez-Riestra, A. Cassatella, R. Monier, and D. de
Martino, ESA International Ultraviolet Explorer Observatory, Madrid,
communicate: "We report observations made with the IUE of the
recurrent nova V3890 Sgr (N Sgr 1962) on May 15.2 UT. At that
time, the visual magnitude of the nova, as derived from the Fine
Error Sensor onboard IUE was 11.63. The spectra were taken in the
low-dispersion mode (0.6 nm resolution), covering the wavelength
range 120-335 nm. The ultraviolet spectrum is characterized by a
faint continuum increasing towards longer wavelengths and by strong
emission lines of N V 124-nm, O I 130.5-nm, Si IV 140-nm, N IV]
148.6-nm, C IV 155-nm, He II 164-nm, O III] 166.3-nm, N III] 175-nm,
Si III] 189-nm, C III] 191-nm, Mg II 280-nm, [Mg V] 293-nm, the He
II Paschen lines, and the O III Bowen lines. The Si III]/C III]
flux ratio is consistent with an electron density < 10E10 cmE-3, if
the abundances are solar. Most of the lines have a broad component
(FWHM about 4000 km/s) and a narrower core (FWHM about 1200 km/s).
This narrow core appears to be stronger in the high-excitation lines
like He II, N V, O III, and [Mg V]. Of special interest is the
very-high-ionization line of [Fe XI] at 264.8 nm, previously observed
only in the sun and in the recurrent nova RS Oph during its 1985
outburst (IAUC 4067) and ascribed to the interaction of the ejected
shell with pre-existing material expelled during the previous
outburst. The observed flux in the [Fe XI] line is 4 x 10E-13 erg
cmE-2 sE-1 and its FWHM is 800 km/s."
Visual magnitude estimates (cf. IAUC 5015): May 17.87 UT, 12.1
(A. Pearce, Scarborough, W.A.); 18.07, 12.2 (P. Schmeer, Bischmisheim,
W. Germany); 19.03, 12.5 (Schmeer); 19.85, 12.5 (Pearce); 20.85, 12.9
(Pearce); 21.86, 13.3 (Pearce); 22.86, 13.6 (Pearce).
EXTRAGALACTIC SiO
R. Mauersberger and C. Henkel, Max-Planck-Institut fur
Radioastronomie, Bonn, report the detection of extragalactic SiO. The
data were obtained in the J = 2-1 line of the ground vibrational
level toward the nucleus of the starburst galaxy NGC 253, using the
IRAM 30-m telescope. No emission was observed toward M82 and IC 342.
A possible interpretation is that the SiO abundance is enhanced in
NGC 253 due to a high gas kinetic temperature.
1990 May 24 (5021) Daniel W. E. Green
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