Central Bureau for Astronomical Telegrams

Central Bureau for Astronomical Telegrams -- Image credits

IAUC 6339: GRO J1744-28; 1993J

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 6338 SEARCH Read IAUC 6340

View IAUC 6339 in .dvi or .ps format.
IAUC number 

                                                  Circular No. 6339
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)


GRO J1744-28
     A. J. Castro-Tirado, Laboratorio de Astrofisica Espacial y
Fisica Fundamental, Madrid; R. Gonzalez-Delgado, Space Telescope
Science Institute; E. Perez, Instituto de Astrofisica de Andalucia,
Granada; and J. M. Rodriguez-Espinosa, Instituto de Astrofisica de
Canarias, report:  "On Mar. 3 and 5, we observed the entire XTE
error box of GRO J1744-28 (IAUC 6309) with the 3.5-m telescope (+
MAGIC in high-resolution mode, 0".31 per pixel) at the German-
Spanish Calar Alto Observatory.  Images were taken using two
narrow-band filters centered at 2.166 microns (Brackett-gamma,
width 0.022 microns) and 2.26 microns (continuum K, width 0.060
microns).  Co-added images (total exposures 1560 s at 2.166 microns
and 250 s at 2.26 microns) were obtained in order to search for Br-
gamma emission-line objects within the XTE error box.  No such
objects brighter than K = 14 were found within the XTE error box or
at the position of the variable radio source (IAUC 6307, 6323) that
has been recently confirmed by ASCA (IAUC 6337) as the radio
counterpart of GRO J1744-28.  Taking into account the optical/
infrared astrometry (IAUC 6315, 6318) and the large N(H) value
derived by ASCA, it seems that 'star C' (K = 13.3, IAUC 6318, 6321)
is a foreground star about 0".5 away from GRO J1744-28 (similar to
GX 17+2, whose optical counterpart is almost coincident with the
position of a foreground G star; Naylor et al. 1991, MNRAS 252,
203).  For a source distance of 7 kpc, we estimate 13.5 < K < 17.5.
Therefore, only deep, high-resolution, and preferably thermal
imaging of GRO J1744-28 while in outburst may reveal the infrared
counterpart."


SUPERNOVA 1993J IN NGC 3031
     H.-U. Zimmermann and B. Aschenbach, Max-Planck-Institut fur
Extraterrestrische Physik; and W. H. G. Lewin, Massachusetts
Institute of Technology, report:  "SN 1993J in M81 has been
monitored twice a year with the HRI detector onboard the x-ray
satellite ROSAT.  The latest measurements from Oct. 1995 confirm
that, after the strong initial decrease of the soft x-ray flux
during the first year, the soft x-ray flux has been continuously
rising since early 1994.  Assuming a temperature of kT = 1.25 keV
and foreground absorption of N(H) = 5.4 x 10E20 cmE-2 as deduced
from a Raymond-Smith fit to PSPC data taken at the end of 1993, the
absorption-corrected luminosity in the ROSAT band (0.1-2.4 keV) in
Oct. 1995 is 5.4 x 10E38 erg/s, which is about 70 percent higher
than in Apr. 1994."

                      (C) Copyright 1996 CBAT
1996 March 8                   (6339)            Daniel W. E. Green

Read IAUC 6338 SEARCH Read IAUC 6340

View IAUC 6339 in .dvi or .ps format.

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

Valid HTML 4.01!