Central Bureau for Astronomical Telegrams
IAUC 6514: SATURN, URANUS AND NEPTUNE; GRO J2058+42
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 6515
.dvi or
.ps format.
Circular No. 6514
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
BMARSDEN@CFA.HARVARD.EDU or DGREEN@CFA.HARVARD.EDU (science)
Phone 617-495-7244/7440/7444 (for emergency use only)
SATURN, URANUS AND NEPTUNE
H. Feuchtgruber, Infrared Space Observatory (ISO) Science
Operations Center and Max-Planck-Institut fur Extraterrestrische
Physik; T. de Graauw, Space Research Organization of the Netherlands
and Kapteyn Astronomical Institute; E. Lellouch, B. Bezard and
T. Encrenaz, Departement de Recherche Spatiale, Observatoire de Paris;
and M. J. Griffin, Queen Mary and Westfield College, report: "During
October and November we observed Saturn, Uranus and Neptune in the
14-45-micron range with the ISO Short Wavelength Spectrometer in
grating mode at a spectral resolution of 1000-1500. On Uranus, eight
H2O emission features were detected (28.43, 28.59, 33.00, 35.91, 39.38,
40.34, 43.89 and 44.19 microns); a very preliminary analysis suggests
that these lines are formed at temperatures of 200-300 K in the microbar
region of the planet's upper atmosphere. Six H2O lines were also
detected on Neptune, and three were found on Saturn. In addition, the
Q branch of the CO2 nu2 band at 14.98 microns was observed in
emission in the spectra of Saturn and Neptune.
GRO J2058+42
C. A. Wilson, NASA Marshall Space Flight Center; T. Strohmayer,
NASA Goddard Space Flight Center and Universities Space Research
Association; and D. Chakrabarty, Massachusetts Institute of
Technology, report: "The Compton Observatory/BATSE instrument has
observed a series of five outbursts from the 195.6-s accreting x-ray
pulsar GRO J2058+42, with a bright initial outburst in Sept. 1995 (IAUC
6238) followed by four weaker (15-20-mCrab pulsed flux in the 20-50-keV
band) outbursts, all spaced by about 110 days. The weak outbursts
have each lasted about two weeks, with a marginal decline in peak
intensity over consecutive outbursts. The most recent outburst peaked
on 1996 Nov. 25 +/- 2 with a 20-50-keV pulsed flux of 14 +/- 1 mCrab. The
barycentric pulse frequency on Nov. 25.0 UT was 5.1125 +/- 0.0001 mHz.
A target-of-opportunity scan of the Compton/OSSE/BATSE error box (IAUC
6239) on Nov. 28 with the Proportional Counter Array (PCA) on the Rossi
X-ray Timing Explorer (RXTE) constrained the 90-percent-confidence
region for the source position to a circle with 4' radius and centered
at R.A. = 20h59m.0, Decl. = +41d43' (equinox 2000.0). RXTE/PCA
observed a peak flux of 11 +/- 1 mCrab (2-30 keV) and a pulse frequency
consistent with the BATSE measurement. Optical observations of the
new error circle are strongly encouraged in order to identify the
optical companion, most likely a Be star."
(C) Copyright 1996 CBAT
1996 December 6 (6514) Brian G. Marsden
Read IAUC 6515
.dvi or
.ps format.
Our Web policy. Index to the CBAT/MPC/ICQ pages.
