Circular No. 3347 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION 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 MXB1730-335 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." VARIABLE ULTRAVIOLET-EXCESS OBJECT 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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