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IAUC 5836: GRO J1008-57; N Oph 1993

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                                                  Circular No. 5836
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)


GRO J1008-57
     M. T. Stollberg, M. H. Finger, R. B. Wilson, B. A. Harmon, B.
C. Rubin, N. S. Zhang, and G. J. Fishman report for the Compton
Gamma Ray Observatory BATSE team:  "Hard x-ray pulsations in the
energy range 20-120 keV are being detected from a previously
uncatalogued source in the Carina-Vela region.  The source location,
determined from the observed times of Earth occultation, is centered
at R.A. = 10h08m, Decl. = -57.5 deg (equinox 2000.0).  The estimated
1-sigma errors are bounded by a box with the following corners:
R.A. = 10h09m.5, Decl. = -57 24'; 10h03m.5, -56 24'; 10h07m.0,
-57 30'; 10h12m.5, -58 42'.  The pulse period on July 19 was 93.587
+/- 0.005 s, corrected to the solar system barycenter.  The present
outburst was first detected on July 14.  The pulsed flux in the
range 20-50 keV increased from a detection threshold of about 50
mCrab to about 1.1 Crab (pulsed) on July 18, and this flux has
continued to increase slightly since that time.  The spectrum of the
phase-averaged pulsed flux between E = 20 and 100 keV on July 23-24
has been fitted by an optically thin thermal bremsstrahlung model
of the form A/E exp(-E/kT), with A = 0.21 +/- 0.02 photon cmE-2
sE-1 and kT = 18.9 +/- 0.9 keV."


NOVA OPHIUCHI 1993
     C. E. Woodward, University of Wyoming; M. A. Greenhouse,
National Air and Space Museum; and D. Van Buren, California Institute
of Technology, write:  "Spectroscopy of N Oph 1993 obtained on June
2.3 UT (62 days after outburst; cf. IAUC 5765) with the Kitt Peak
National Observatory 2.1-m telescope (+ CRSP) reveals the following
infrared coronal lines (wavelengths listed are observed values,
with uncertainty in the last digit given in parentheses): [Ca VIII]
2.322(2)-microns (2P1/2-2P3/2) and [Si VII] 2.470(2)-microns (3P2-
3P1).  Emission from hydrogen (Brackett-gamma 2.169(1)-microns) and
helium (He I 2.060(2)-microns) also were present in the spectra.
The observed integrated intensities were (in units of 10E-19 W/cm2):
Brackett-gamma, 1.06 +/- 0.01; [Ca VIII], 0.26 +/- 0.05; [Si VII],
0.65 +/- 0.13.  The lines were velocity-resolved at about 3600 km/s
FWHM.  The rapid onset of coronal line emission in N Oph 1993 is
similar to that observed in V1500 Cyg and V446 Her.  Further
spectroscopy is encouraged."


1993 July 27                   (5836)            Daniel W. E. Green

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