Central Bureau for Astronomical Telegrams
IAUC 4993: 1990H; 1989c1
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Circular No. 4993
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
SUPERNOVA 1990H IN NGC 3294
E. Cappellaro, S. Benetti, and M. Turatto, Asiago Astrophysical
Observatory, report: "We confirm that SN 1990H in NGC 3294 (cf. IAUC
4992) is indeed a supernova. A CCD spectrum obtained on Apr. 11.9 UT
at the 1.82-m telescope of Cima Ekar shows the typical features of a
type-II SN, appearing very similar to the spectra of SN 1988A in the
plateau phase. The spectrum is dominated by broad H-alpha with a
P-Cyg profile (the expansion velocity from the minimum of the
absorption is 6880 km/s) and by other strong emission features measured
at 467.9, 493.7, 504.3, 544.4, 556.2, 569.6, 593.4, 617.0, 628.5, and
656.9 nm."
COMET AUSTIN (1989c1)
W. J. Altenhoff, E. Kreysa, J. Schmidt, and J. B. Schraml, Max-
Planck-Institut fur Radioastronomie, Bonn; and C. Thum, Institut de
Radio Astronomie Millimetrique, Granada, write: "We have observed
continuum emission of comet Austin at 250 GHz with the IRAM 30-m
telescope. Preliminary evaluation results in 11.0 +/- 2.7 mJy on
Mar. 15 and 12.8 +/- 3.4 mJy on Mar. 16. The comet was at heliocentric
distance 0.75 AU and geocentric distance 1.47 AU (probably the
largest distance at which a radio signal of a comet has been detected).
The deduced grain halo of comet Austin seems to be similar in grain
size, photometric diameter, mass, etc., to that of P/Halley in 1986
April."
R. D. Gehrz and E. P. Ney, University of Minnesota, report the
following infrared magnitudes obtained with the 0.76-m telescope of
O'Brien Observatory on Apr. 12.78 UT (20" diaphragm, 34" beam
throw; cf. IAUC 4988): 2.3 microns, +5.34; 3.6 microns, +1.52; 4.9
microns, -0.32; 8.6 microns, -2.74; 10.7 microns, -3.50; 12.2 microns,
-3.72.
Further total visual magnitude estimates: Apr. 7.06 UT, 4.8 (G.
Kronk, Troy, IL, 20x80 binoculars; 1 deg tail in p.a. about 40 deg);
7.85, 5.7 (J. D. Shanklin, Cambridge, England, 20x80 binoculars; 40'
tail in p.a. 40 deg); 8.78, 4.7 (R. Haver, Rome, Italy, 15x80
binoculars; 0.5 deg tail in p.a. 50 deg); 9.02, 5.3 (J. E. Bortle,
Stormville, NY, 15x80 binoculars); 9.81, 5.1 (H.-M. Hahn, Cologne, W.
Germany, 11x80 binoculars); 10.80, 4.8 (H. Mikuz, Ljubljana, Yugoslavia,
15x80 binoculars; 1 deg tail in p.a. 20 deg); 11.79, 3.8 (S.
Baroni, Milan, Italy, 40x80 binoculars; 0.3 deg tail in p.a. 20 deg);
13.02, 5.2 (Bortle).
1990 April 13 (4993) Daniel W. E. Green
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