Central Bureau for Astronomical Telegrams

Central Bureau for Astronomical Telegrams -- Image credits

IAUC 5890: HARD X-RAY TRANSIENT; X-RAY N IN Vel; 1993a

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 5889 SEARCH Read IAUC 5891

View IAUC 5890 in .dvi or .ps format.
IAUC number 

                                                  Circular No. 5890
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)


HARD X-RAY TRANSIENT
     B. A. Harmon, S. N. Zhang, G. J. Fishman, and C. A. Wilson,
Marshall Space Flight Center, NASA, report for the COMPTON Observatory
BATSE Team:  "An increase in hard x-ray flux in the band 20-
230 keV has been observed since Nov. 10 in the Aquila-Scutum region
using Earth-occultation monitoring.  Maximum intensity from preliminary
data was on Nov. 13 at about 100-150 mCrab, with a hard spectrum
extending above 200 keV.  Its location is not well-determined
at this time; the error box is +/- 0o.5 degrees along a line
between the locations R.A. = 18h28m, Decl. = +8o and 18h52m, -4o.
Assuming that the source remains bright for several more days, the
location accuracy should improve."


X-RAY NOVA IN VELA
     M. Della Valle, European Southern Observatory; and S. Benetti,
Department of Astronomy, University of Texas at Austin, report: "We
have found the probable optical counterpart of the x-ray source in
Vela (cf. IAUC 5864, 5886) at V = 14.6, B-V = +0.3, V-R = +0.1,
near the edge of the ASCA error box (IAUC 5888), on a CCD frame
obtained on Nov. 17.3 UT with the ESO/MPI 2.2-m telescope (+ EFOSC2)
at La Silla.  A preliminary position measured on the CCD frames is
R.A. = 10h11m32s, Decl. = -44o49'41" (equinox 1950.0).  Analysis of
a spectrogram (range 470-690 nm, resolution about 0.7 nm) secured
with the same equipment shows a relatively blue continuum, with a
broad H-alpha emission line (FWHM about 3 nm) clearly separated
into two components measured at 655.6 and 657.3 nm.  The emission
line due to H-beta is also visible.  Inspection of the ESO B
Schmidt plate shows the probable progenitor at B about 19."


COMET MUELLER (1993a)
     Total visual magnitude estimates:  Sept. 18.23 UT, 10.3 (C. S.
Morris, Pine Mountain Club, CA, 0.26-m reflector); Oct. 10.19, 9.3
(G. W. Kronk, Troy, IL, 20x80 binoculars); 25.38, 9.1 (J. E. Bortle,
Stormville, NY, 0.32-m reflector); Nov. 4.75, 9.1 (A. Diepvens,
Balen, Belgium, 0.15-m refractor); 16.11, 9.2 (C. E. Spratt,
Victoria, BC, 0.20-m reflector).


1993 November 17               (5890)            Daniel W. E. Green

Read IAUC 5889 SEARCH Read IAUC 5891

View IAUC 5890 in .dvi or .ps format.

Our Web policy. Index to the CBAT/MPC/ICQ pages.

Valid HTML 4.01!