Central Bureau for Astronomical Telegrams
IAUC 7138: V2134 Oph = MXB 1659-29; 1999bh
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Circular No. 7138
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
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V2134 OPHIUCHI = MXB 1659-29
J. in 't Zand and J. Heise, Space Research Organization of the
Netherlands (SRON), Utrecht; M. J. S. Smith, BeppoSAX Science
Operations Center (SOC), Rome, and SRON; M. Cocchi and L. Natalucci,
Istituto di Astrofisica Spaziale, CNR, Rome; and G. Celidonio, SOC,
communicate: "During Apr. 2.06-3.47 UT, a transient x-ray source
was detected through an observation of the Galactic-center field
with Wide Field Camera (WFC) unit 1 on BeppoSAX. The location is
R.A. = 17h02m06s, Decl. = -29o56'.7 (equinox 2000.0; 99-percent
confidence error radius 2'). This coincides with the position of
MXB 1659-29, a transient x-ray burster last seen active 21 years
ago. The average WFC-measured flux is 18 mCrab (2-9 keV). There
is variability of a factor of 2 on a 5-hr timescale. Since its
launch in 1996, WFC did not detect any other bursts from this
position."
T. Augusteijn, European Southern Observatory; L. Freyhammmer,
Vrije Universiteit, Brussels; and J. in 't Zand, Space Research
Organization of the Netherlands, Utrecht; report: "Optical
observations of V2134 Oph (the optical counterpart of the x-ray
transient MXB 1659-29, detected by BeppoSAX), were made on Apr.
3.41 UT with the Dutch 0.90-m telescope at La Silla, showing the
source to be bright at V = 18.3 +/- 0.1. A spectrum (range 390-680
nm, resolution 0.6 nm) taken with the Danish 1.54-m telescope (+
DFOSC) on Apr. 4.39 showed the typical spectrum of a low-mass x-ray
binary in an x-ray-bright phase, exhibiting emission lines of He II
468.6-nm, the C III/N III 464-/465-nm blend, and the Balmer series
(H-alpha, with EW about 0.5 nm and FWHM about 700 km/s). Our
observations confirm that the source is undergoing an outburst
similar to the one detected in 1978 (Doxsey et al. 1979, Ap.J. 228,
L67)."
SUPERNOVA 1999bh IN NGC 3435
G. Aldering and P. Nugent, Lawrence Berkeley National
Laboratory (LBNL); R. Ellis, Institute of Astronomy, University of
Cambridge; and S. Perlmutter, LBNL, have obtained a spectrum
(400-700 nm) of SN 1999bh (IAUC 7135) through service observations
by D. Folha at the Issac Newton Telescope, La Palma, on Apr. 2 UT.
The spectrum is that of a type-Ia supernova within one week after
maximum light. The redshift of the supernova is about 8400 km/s.
(C) Copyright 1999 CBAT
1999 April 5 (7138) Daniel W. E. Green
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