Central Bureau for Astronomical Telegrams
IAUC 5878: X-RAY NOVAE; BINARY Millisec PULSAR IN GRO J0752+17
The following International Astronomical Union Circular may be linked-to from your own Web pages, but must not otherwise be redistributed (see these notes on the conditions under which circulars are made available on our WWW site).
Read IAUC 5879
.dvi or
.ps format.
Circular No. 5878
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
Telephone 617-495-7244/7440/7444 (for emergency use only)
TWX 710-320-6842 ASTROGRAM CAM EASYLINK 62794505
MARSDEN@CFA or GREEN@CFA (.SPAN, .BITNET or .HARVARD.EDU)
X-RAY NOVAE
A. Kaniovsky, K. Borozdin, and R. Sunyaev, on behalf of the
Mir-Kvant team, report: "The soft x-ray transient GRS 1009-45,
discovered by Granat/WATCH and more precisely localized by BATSE (IAUC
5864), was observed by the TTM and HEXE instruments of Mir-Kvant on
Sept. 30. Preliminary analysis shows that the source spectrum in
the band 2-200 keV is similar to the spectra of the x-ray novae QZ
Vul = GS 2000+25 and GU Mus (= Nova Mus 1991) = GRS 1124-684. A
bright, soft component can be approximated by a black-body spectrum
with a temperature of 0.52 +/- 0.03 keV. The source spectrum at
the higher energies 10-100 keV is well approximated by a power law
with spectral index -2.53 +/- 0.05. The flux from the source at 3
and 20 keV was equal to 1 and 0.1 Crab unit, respectively."
K. Borozdin, V. Arefiev, and R. Sunyaev, on behalf of the Mir-
Kvant-TTM team, report: "Mir-Kvant observed the hard x-ray transient
GRS 1716-249 = GRO J1719-24 and found that the source spectrum
in the band 2-27 keV is approximated by a single power law with
spectral index -1.57 +/- 0.13. No trails of the soft component
were detected in the spectrum; it is reminiscent of the spectra of
V1357 Cyg = Cygnus X-1, 1E 1740.7-2942, and the x-ray novae V404
Cyg = GS 2023+338 and GRO J0422+32. The flux was continuously
growing, from 200 mCrab on Sept. 26 and 550 mCrab on Sept. 27 up to
750 mCrab on Oct. 3 in the band 12-17 keV."
BINARY MILLISECOND PULSAR IN GRO J0752+17
S. C. Lundgren, A. F. Zepka, and J. M. Cordes, Cornell University,
report: "We announce the discovery of a binary millisecond
pulsar in the EGRET source error box for GRO J0752+17. The discovery
was made in a pulsar search conducted at Arecibo Observatory
targeted at unidentified EGRET high-energy gamma-ray source error
boxes. The pulsar has a 3.5-ms spin period, an 8.5-hr orbital
period, a 430-MHz flux density of 10 mJy, and a dispersion measure of
30 pc cmE-3. Based on an estimated success rate of one pulsar per
150 degE2 above 3 mJy in past high-latitude surveys, the probability
of chance association of a pulsar with one of the observed error
boxes is 2 percent. X-ray and gamma-ray studies will be necessary
to confirm the association of the high-energy source with the radio
pulsar."
1993 October 12 (5878) Daniel W. E. Green
Read IAUC 5879
.dvi or
.ps format.
Our Web policy. Index to the CBAT/MPC/ICQ pages.
