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IAUC 6976: 1998cx; XTE J2123-058; N Oph 1998

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                                                 Circular No. 6976
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
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SUPERNOVA 1998cx IN NGC 6209
     A. Piemonte, Pontificia Universidad Catolica; and F. Patat,
European Southern Observatory (ESO), report that they obtained a
CCD spectrogram (60-min exposure, range 315-970 nm, resolution 1.5
nm) of SN 1998cx (cf. IAUC 6970) with the ESO 1.5-m telescope (+
Boller & Chivens spectrograph) on July 22.08 UT at La Silla.  A
full reduction of the spectrum shows that this supernova is typical
of type-Ia events at intermediate phases; it is dominated by Fe II
lines, although some features arising from intermediate elements
(Ca II and Si II) are still present.  This and the expansion
velocity deduced from Ca H and K and the Ca II infrared triplet
(10 800 km/s) suggest that SN 1998cx has been observed around 5-6
weeks after maximum light.  The spectrum is very similar to that
shown by SN 1994D at similar phases (Patat et al. 1995, MNRAS 278,
111).  The recession velocity of the parent galaxy is 5865 km/s
(Mathewson et al. 1992, Ap.J. Suppl. 81, 413).


XTE J2123-058
     R. I. Hynes, University of Sussex; P. A. Charles, University
of Oxford; C. A. Haswell, University of Sussex; and J. Casares, M.
Serra-Ricart, and C. Zurita, Instituto de Astrofisica de Canarias,
report: "Time-resolved spectroscopy (range 350-685 nm) of the x-ray
transient XTE J2123-058 was obtained with the 4.2-m William
Herschel Telescope at La Palma on July 19-20.  The spectra reveal a
nearly featureless continuum with only C III/N III 464.0-nm
(average equivalent width 0.20 nm) and He II 468.6-nm (equivalent
width 0.23 nm) emission being prominent.  He II 468.6-nm shows a
radial-velocity modulation with a period of 6.05 +/- 0.10 hr,
consistent with the photometric periods of Tomsick et al. (IAUC
6972) and Ilovaisky and Chevalier (IAUC 6975) and confirming that
the photometric period is indeed the orbital period of the system.
The velocity semi-amplitude is about 180 km/s, with maximum radial
velocity close to photometric phase 0.75, suggesting an association
with the compact object or disk.  Further monitoring of this system
is encouraged."


NOVA OPHIUCHI 1998
     Additional CCD photometry by D. Hanzl, Brno, Czech Republic
(cf. IAUC 6943, 6955):  June 29.891 UT, V = 13.57 +/- 0.06, B-V =
+0.68 +/- 0.1; July 3.905, V = 13.85 +/- 0.03, -; 18.874, V = 14.41
+/- 0.06, -; 20.886, V = 14.76 +/- 0.06, -.

                      (C) Copyright 1998 CBAT
1998 July 23                   (6976)            Daniel W. E. Green

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