Central Bureau for Astronomical Telegrams
IAUC 5930: PSR 0329+54; Cyg X-1
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Circular No. 5930
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)
PSR 0329+54
R. D. Dagkesamansky, Pushchino Radio Astronomy Observatory;
and Y. P. Shitov, Pulsar Laboratory, Lebedev Physical Institute,
report: "Using the pulsar timing technique, T. V. Shabanova has
detected a probable planetary system around PSR 0329+54, one of the
brightest pulsars. The total data set analyzed by Shabanova extends
over 25 yr and consists of Pushchino timing measurements during
1979-Jan. 1994 and some previously published data concerning pulse
arrival times (Downs and Reichley 1983, Ap.J. Suppl. 53, 169; Downs
and Krause-Polstorff 1986, Ap.J. Suppl. 62, 81). The analysis
suggests that PSR 0329+54 is orbited by a planet-like body with an
orbital period of about 6140 days. The projected semimajor axis of
the pulsar orbit is 17.8 light-ms, and the orbital eccentricity is
quite large (0.23). The mass function of the binary system is 1.4
x 10E-16 solar mass; i.e., assuming that the pulsar mass is 1.4
solar masses, then the companion mass is 2.0 Me/sin i [Me = earth
mass] and has orbital radius about 7.3 AU. Another sinusoidal
modulation of the timing residuals with a period about 1110 days
and amplitude 1 ms is observed. Assuming the existence of a second
planet, the corresponding mass function is 4.5 x 10E-19 solar mass;
i.e., the second planet's mass is 0.3 Me/sin i and its orbital
radius is about 2.3 AU."
CYGNUS X-1
B. F. Phlips, Universities Space Research Association and Naval
Research Laboratory (NRL); M. D. Leising, Clemson University; K.
McNaron-Brown, George Mason University; and J. E. Grove, W. N.
Johnson, J. D. Kurfess, and M. S. Strickman, NRL, report for the
Compton Observatory OSSE Team: "OSSE is observing Cygnus X-1
between Feb. 1 and 8, based on information from BATSE that the
source is in a low state. We measured the integrated 45- to 140-keV
flux to be 1.5 and 1.1 (+/- 0.1) x 10E-2 photon cmE-2 sE-1 for the
first two days of the observation, respectively. This is one-fifth
of the flux in the low, or gamma1, state observed by HEAO-3 (Ling
et al. 1987, Ap.J. 321, L117). Optically-thin thermal bremsstrahlung
models fit the spectra well and produced temperatures of 56 +/- 8 and
62 +/- 8 keV for Feb. 1 and 2, respectively. These temperatures are
half of the values typically measured by OSSE for Cygnus X-1. We
find no evidence for the enhanced 1-MeV emission associated with low
states as reported by Ling et al. Observations at other wavelengths
are encouraged."
1994 February 7 (5930) Daniel W. E. Green
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