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                                                  Circular No. 3347
Central Bureau for Astronomical Telegrams
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
TWX 710-320-6842 ASTROGRAM CAM     Telephone 617-864-5758

     O. P. N. Calla, S. M. Bhandari, M. R. Deshpande and O. M. Vats
Hari, Space Applications Centre and Physical Research Laboratory,
Ahmedabad, communicate: "We report the discovery of microwave
bursts from the Rapid Burster MXB1730-335 (cf. IAUC 3344) on Apr.
15.0 and 16.0 UT.  The broad characteristics of the bursts are:

     1979 UT                         d(b)    R     A   d(s)
     Apr. 14d23h14m50s-14d23h16m55s  17s   12s5    3    45s
          16 00 13 00 -16 00 15 05    7.5   4.25   6    70

Here d(b) is the duration of an individual burst, R the risetime, A
the peak amplitude (in db) and d(s) the silent duration.  The observations
were made during Apr. 14d22h50m-15d00h12m and Apr. 15d22h25m-16d00h35m
UT at 4.1 GHz with the 14-m parabolic antenna located at
the Space Applications Centre and associated electronics including
the parametric amplifier and total power receiver having an overall
system temperature of 130 K.  The activity on Apr. 15.0 started
with one burst of ~ 17-s duration and was followed 45 s later by a
series of six very narrow spikes.  On the other hand, the initial
burst on Apr. 16.0 was followed ~ 70 s later by a pair of relatively
weaker bursts.  We feel that observations of microwave bursts
from x-ray bursters would provide additional clues toward a better
understanding of the mass-accretion processes involving x-ray
emission from compact stellar objects.  The present observations
indicate that MXB1730-335 is currently active at near infrared
wavelengths.  Observations in the far infrared and continued x-ray
monitoring from satellites will be of high scientific value."

     B. Takase, Tokyo Astronomical Observatory, reports that T.
Noguchi, M. Kondo and H. Maehara have detected a variable
ultraviolet-excess object on UGR three-image plates taken with the Kiso
105-cm Schmidt telescope.  On Mar. 25.7 UT (observers Takase and S.
Okamura), U = 16.6 +/- 0.3, G = 17.3 +/- 0.5, R = 15.8 +/- 0.3.  On Mar.
31.6 UT (observers Kondo and Noguchi), U > 18.0, G >~ 17.0, R = 16.3
+/- 0.3.  The position is R.A. = 14h23m19s.91, Decl. = +25o53'34".9 (equinox
1950.0).  On the Palomar Sky Survey prints the object appears to
have blue and red magnitudes of ~ 17.5-18 and 16-16.5, respectively.

1979 April 18                  (3347)              Brian G. Marsden

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