Central Bureau for Astronomical Telegrams
IAUC 6711: 1997da; 1997db; Cep X-4
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Circular No. 6711
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
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SUPERNOVA 1997da IN IC 1216
M. Schwartz reports his discovery of an apparent supernova
(mag about 17) on a CCD image taken with the 0.35-m Tenagra
Observatory patrol telescope on July 31.399 UT. SN 1997da is
located 3" west and 6" south of the nucleus of IC 1216. G. V.
Williams, Smithsonian Astrophysical Observatory, provides the
following measurement for SN 1997da from a GIF image supplied by
Schwartz: R.A. = 16h15m54s.96, Decl. = +68o20'53".3 (equinox
2000.0; uncertainty about 1"). A. V. Filippenko, D. C. Leonard,
and A. M. Gilbert, University of California at Berkeley, report
that CCD spectra (range 330-1000 nm) obtained with the Lick 3-m
Shane reflector on Aug. 4 show this to be a supernova of type II,
probably within 1.5 months after outburst; H-alpha has a P-Cyg
profile, and there are some Fe II lines.
SUPERNOVA 1997db IN UGC 11861
Schwartz also reports his discovery of an apparent supernova
on a CCD image taken on Aug. 2.30 UT. The following position and
magnitude were measured by W. Offutt (Cloudcroft, NM) from an image
supplied by Schwartz: R.A. = 21h56m20s.53, Decl. = +73o14'49".4
(equinox 2000.0), V = 16.9. Note that SN 1995ag was in the same
galaxy (IAUC 6244).
Filippenko et al. report that CCD spectra (range 330-1000 nm)
obtained with the 3-m Shane reflector on Aug. 4 show that SN 1997db
is a supernova of type II, many months past outburst and entering
the nebular phase. There are prominent emission lines of [Ca II]
730-nm and the Ca II near-infrared triplet, as well as very strong
H-alpha. SN 1997db is located about 14" west and 50" south from
the ill-defined host-galaxy nucleus.
CEPHEUS X-4
R. W. Argyle, Royal Greenwich Observatory, reports an accurate
optical position for the suggested counterpart to Cepheus X-4 (IAUC
6698) obtained with the Carlsberg Automatic Meridian Circle on La
Palma. The position from 8 observations for the International
Celestial Reference Frame is: R.A. = 21h39m30s.630 +/- 0s.012,
Decl. = +56o59'09".99 +/- 0".12 (equinox J2000.0; epoch 1997.55).
Photometry is unreliable, but the object certainly shows signs of
variability.
(C) Copyright 1997 CBAT
1997 August 4 (6711) Daniel W. E. Green
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