Central Bureau for Astronomical Telegrams
IAUC 4679: 1987A; Sct X-1; NSV 6708
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Circular No. 4679
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
J. D. Bregman, F. C. Witteborn, and D. H. Wooden, NASA Ames
Research Center; D. M. Rank, Lick Observatory; and M. Cohen, University
of California at Berkeley, write: "We have obtained 1.7-13-micron
spectra of SN 1987A using the Kuiper Airborne Observatory on the nights
of Oct. 24, 28, 31, Nov. 2, and 4 UT. The 1-0 band of CO is present,
but is about 5 times weaker than in 1988 April. The relative
intensities and shapes of the P and R branches have shanged in a manner
that indicates a substantially lower vibration-rotation temperature
than the 3000 K measured in April. Forbidden lines of Ni and Ar have
also decreased in strength, with the [Ni II] 6.64-micron line
decreasing by 3.3 times and the [Ar II] 6.98-micron line decreasing by
11 times. The line fluxes are (in units of W/cm2): [Ni II] (6.64
microns) = 2.0 x 10E-17, [Ar II] (6.98 microns) = 1.9 x 10E-18, [Ni I]
(7.51 microns) = 1.2 x 10E-18. The redshift of the [Ni II] line, which
we attributed to electron scattering in the April data, has decreased
from 770 to 400 km/s. The width of the [Ni II] line (about 3000 km/s)
has not changed since April. No H lines were detected including all
lines between Paschen-alpha (1.87 microns) and Humphreys-alpha (12.4
microns). The brightness of the continuum from 6-7 microns has not
changed since April, and has a flux of 3.2 x 10E-17 W/cm2/micron.
There is a broad feature about 1 micron wide and peaking near 8.8 microns."
Visual magnitude estimates by P. Williams, Heathcote, N.S.W.:
Oct. 10.55 UT, 9.5; 15.51, 9.6; Nov. 4.43, 10.2; 12.43, 10.2; 13.43, 10.3.
SCUTUM X-1
F. Makino and the Ginga Team telex: "A pulsating x-ray emission
from Sct X-1 was discovered with the Large Area Counters aboard Ginga
on Nov. 14. The pulse period was 110.99 +/- 0.02 s on Nov. 14.6 UT.
The x-ray intensity was 1-2 mCrab and exhibited erratic variation. The
spectrum showed a sharp cutoff below about 4 keV, suggesting heavy
absorption (Hill et al. 1974, Ap.J. 189, L69)."
NSV 6708
Visual magnitude estimates (cf. IAUC 4661) by R. H. McNaught,
Siding Spring Observatory: Oct. 2.41 UT, 13.8; 4.41, 14.0;
9.42, 13.9; 11.40, 14.1; 18.41, 14.0; Nov. 20.74, 12.8.
1988 November 23 (4679) Daniel W. E. Green
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