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IAUC 7895: XTE J0929-314; V2116 Oph

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                                                  Circular No. 7895
Central Bureau for Astronomical Telegrams
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
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XTE J0929-314
     A. J. Castro-Tirado, Instituto de Astrofisica de Andalucia,
Consejo Superior de Investigaciones Cientificas (IAA-CSIC),
Granada; A. Caccianiga, Osservatorio Astronomico di Brera, Milano;
J. Gorosabel, IAA-CSIC; P. Kilmartin, University of Canterbury; P.
Tristram and P. Yock, University of Auckland; C. Sanchez-Fernandez,
Laboratorio de Astrofisica Espacial y Fisica Fundamental, Instituto
Nacional de Tecnica Aeroespacial, Madrid; and M. E. Alcoholado-
Feltstrom, Sociedad Malaguena de Astronomia, Malaga, communicate:
"We have observed the optical counterpart of the x-ray transient
XTE J0929-314 (IAUC 7888, 7889, 7893) with the European Southern
Observatory 3.6-m telescope at La Silla.  Two 1200-s spectra (350-
800 nm) were obtained on May 6.96 and 7.96 UT.  The combined
spectrum shows emission lines from the C III-N III (464.0-465.0 nm)
blend (EW = 0.14 nm for N III) and H-alpha (656.3 nm, EW = 0.14
nm).  These lines are superposed on a blue continuum and are
typical of soft-x-ray transients in outburst.  Monitoring with the
0.6-m telescope (+ MOA camera) at Mt. John Observatory reveals that
the counterpart has not changed in brightness by more than 0.1 mag
since May 1.6.  Additional spectroscopy and photometry during the
outburst will be highly valuable."

     F. Jablonski, D. Cieslinski, and J. Braga, Instituto Nacional
de Pesquisas Espaciais, Sao Jose dos Campos; and M. G. Pereira,
Universidade Estadual Feira de Santana, report that they have
detected optical pulsations from V2116 Oph, the visible/infrared
counterpart to GX 1+4, in CCD Cousins-R observations obtained on
Mar. 29.21-29.35 (1.6-m telescope) and on Apr. 4.28-4.34 and 5.20-
5.34 UT (0.6-m telescope) at Laboratorio Nacional de Astrofisica in
southern Brazil (cf. Jablonski et al. 1996, Ap.J. 482, L171).  The
heliocentric period of the pulsations was 137.67 +/- 0.07 s on Mar.
29 and 137.3 +/- 0.3 s on Apr. 4 and 5, with pulsed semiamplitudes
of 2.5, 2.0, and 0.6 percent, respectively.  These are the longest
values for the rotational period in this pulsar since its discovery
in 1970, and the period derivative calculated with respect to the
BATSE measurement on 2000 May 26 (cf.
is +1.63 s/yr (significantly less than the trend of +2 s/yr
observed since the beginning of the BATSE era).  The optical
brightness of V2116 Oph was R = 15.83-16.22, close to the median
value for this object.

                      (C) Copyright 2002 CBAT
2002 May 9                     (7895)            Daniel W. E. Green

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