Central Bureau for Astronomical Telegrams
IAUC 4739: 1987A; 3C 279
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Read IAUC 4740
Circular No. 4739
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 1987A IN THE LARGE MAGELLANIC CLOUD
P. R. Wood and D. J. Faulkner, Mount Stromlo and Siding Spring
Observatories, write: "Coude echelle spectra (resolution 80 000) of
SN 1987A taken with the Anglo-Australian Telescope on 1988 Oct. 16
show narrow circumstellar emission lines extending to 2".5 from the
supernova. With the slit aligned along position angle 0 deg, there
is a velocity gradient of 3 km/s/arcsec evident along the emission
lines, with material to the north of the supernova being blueshifted.
Along p.a. 90 deg, the velocity gradient is small, 0.5 km/s/arcsec,
west being blueshifted. These results indicate that the stellar wind
from the progenitor of SN 1987A was asymmetric, possibly bipolar. If
the wind were bipolar, then we note that the mystery spot and speckle
image elongation lie close to the direction of the bipolar axis."
W. J. Couch and D. F. Malin, Anglo-Australian Observatory, report:
"B, V, and R Anglo-Australian Telescope plates taken of the light
echoes on Feb. 5 confirm the existence of the new light-echo feature
reported by Bond et al. (IAUC 4733). We measure a radius of 8".1.
The inner echo ring now has a radius of 48".4 and appears concentric
with the supernova. The outer ring, reported by us to be eccentric
(IAUC 4633), ranges from 79".1 to 83".4 from the supernova, implying that
the sheet of material being illuminated is inclined at about 45 deg
to the plane of the sky. There is evidence of splitting in sections
of both rings. Three new light-echo features are also seen on all
three plates. The most prominent is a short arc from p.a. 140 deg to
170 deg at a radius of 64".4. This implies that the scattering
material is 230 pc in front of the supernova. Its surface brightness
is, in all three colors, similar to that in the brightest regions
of the other rings. The two other features are fainter, lie at
radii of 42".0 and 87".7, and extend from p.a. 205 deg to 295 deg and
245 deg to 330 deg, respectively."
3C 279
M. Kidger and J. Casares, Instituto de Astrofisica de Canarias,
write: "Near-infrared observations were made with the 1.5-m Carlos
Sanchez Telescope in Tenerife on Jan. 22, very close to the time of
the Ginga observations reported on IAUC 4736. The magnitude in K,
10.72 +/- 0.06, agrees fairly closely with earlier observations on Jan.
9 (K = 10.60 +/- 0.02, H = 11.43 +/- 0.03, J = 12.63 +/- 0.06). This
suggests a fade of only about 50 percent since similar measures last
April (cf. IAUC 4595)."
1989 February 16 (4739) Daniel W. E. Green
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