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IAUC 5474: GALACTIC CENTER REGION; 1992 AC

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                                                  Circular No. 5474
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 or GREEN@CFA.BITNET    MARSDEN or GREEN@CFAPS2.SPAN


GALACTIC CENTER REGION
     M. Gilfanov, E. Churazov, A. Claret and J. P. Dezalay, on
behalf of the Granat team (Space Research Institute, Moscow; Centre
d'Etude Spatiale des Rayonnements, Toulouse; Service d'Astrophysique
du CEA, Saclay), communicate:  "The Granat observatory performed a
set of 6 observations of the galactic center region between Feb. 17
and Mar. 2.  Five sources have been significantly detected on the
combined 40- to 100-keV image:  GX 354-0 [flux increased gradually
from < 22 mCrab (3-sigma upper limit) on Feb. 17-19 up to about 75
mCrab on Mar. 1-5]; 1E 1740.7-2942 (IAUC 5472); GX 1+4 (about 35
mCrab on average; apparently variable); Terzan 2 (about 20 mCrab
average flux); SLX 1735-269 (about 20 mCrab average flux).  The
average 40- to 100-keV flux from GRS 1758-258 was restricted to < 20
mCrab (3-sigma upper limit) --- i.e., < 25 percent of the flux
observed by SIGMA in 1990.  4U 1700-37 was detected at the level of
110 mCrab during Feb. 17-18 observations (in all other observations
it was out of SIGMA's field-of-view).  1E 1740.7-2942 was significantly
detected in each individual observation.  The upper limit on
the averaged flux of the narrow 511-keV line is 1.5 x 10E-3 photon
sE-1 cmE-2 (3-sigma).  The Granat observatory will continue the
survey of the galactic center region on Mar. 17."


1992 AC
     Extension to the ephemeris on IAUC 5442:

1992 TT     R. A. (2000) Decl.     Delta      r    Elong. Phase      V
Mar. 19    11 48.58    +53 47.2    0.377    1.258  126.7   39.4     13.5
     29    12 03.87    +51 59.8    0.424    1.286  124.3   39.9     13.9
Apr.  8    12 16.11    +48 56.2    0.476    1.321  122.6   39.7     14.2
     18    12 26.91    +44 59.1    0.534    1.361  121.4   39.0     14.5
     28    12 37.25    +40 27.5    0.597    1.405  120.1   38.3     14.8
May   8    12 47.77    +35 36.2    0.668    1.452  118.5   37.6     15.1
     18    12 58.83    +30 37.9    0.748    1.503  116.5   37.0     15.4
     28    13 10.50    +25 43.0    0.837    1.555  114.0   36.5     15.7
June  7    13 22.83    +20 57.8    0.936    1.609  111.0   36.1     16.0
     17    13 35.84    +16 27.1    1.045    1.663  107.6   35.6     16.3
     27    13 49.43    +12 13.6    1.163    1.718  103.9   35.0     16.5
July  7    14 03.60    + 8 18.0    1.290    1.774   99.9   34.4     16.8
     17    14 18.30    + 4 40.8    1.424    1.828   95.6   33.6     17.1


1992 March 13                  (5474)             Daniel W. E. Green

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