Central Bureau for Astronomical Telegrams
IAUC 4597: 1988K; 1988L
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Read IAUC 4598
Circular No. 4597
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
TWX 710-320-6842 ASTROGRAM CAM Telephone 617-495-7244/7440/7444
MARSDEN or GREEN@CFA.BITNET MARSDEN or GREEN@CFAPS2.SPAN
SUPERNOVA 1988K IN UGC 08179
A. V. Filippenko, University of California, Berkeley, writes:
"The spectrum of SN 1988K described on IAUC 4580 has been fully
calibrated by D. P. Schneider, Institute for Advanced Study. Contrary
to the earlier report, there is no narrow emission line at 558 nm,
and the 610-nm absorption trough is not excessively strong. The object
appears to be a normal type Ia supernova, near maximum brightness when
the spectrum was obtained on Apr. 14. H-alpha emission at a redshift
of 0.053 was detected in the host galaxy."
SUPERNOVA 1988L IN NGC 5850
J. R. Graham, Palomar Observatory, reports: "T. Boroson and B.
Oke used the double spectrograph on the Hale 0.5-m telescope on May 9
to observe SN 1988L. My reduction of the data over 430-600 nm
confirms that the object is indeed a type I supernova. It is
apparently a type Ia supernova 20-50 days after maximum. However, the
infrared colours (IAUC 4590) are much too blue for a type Ia SN of
this age. Given that the current data do not cover the characteristic
610-nm absorption the classification should therefore be tentative.
This supernova bears some similarity to the peculiar type I SNe 1983I
and 1983V (which might have been helium-poor supernovae of type Ib)."
Filippenko also reports: "A spectrum (range 393-823 nm,
resolution 1.5-2 nm) obtained with the 3-m Shane reflector (+ CCD
spectrograph) at the Lick Observatory on May 11 by H. Spinrad and P. J.
McCarthy shows that SN 1988L (IAUC 4590) is a relatively helium-rich
type Ib supernova within a month past maximum brightness. The He I
587.6-nm absorption line is strong, but O I 777.4 nm is also
prominent. SN 1988L may therefore represent a transition between the
helium-rich and oxygen-rich extreme cases discussed by Wheeler et al.
(1987, Ap.J.Lett. 313, L69). As in the type Ib SN 1987K (IAUC 4587)
weak, broad H-alpha emission is detected. The spectroscopic
resemblance to a hydrogen-poor type II supernova suggests that type II
and type Ib supernovae form a continuous sequence in which the mass of
the hydrogen envelope is the main variable. SN 1988L is superposed
on, and surrounded by, H II regions, but it is not in one of the two
main spiral arms of NGC 5850."
1988 May 14 (4597) Brian G. Marsden
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