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ETC Imaging of GRB 941014

On 14 October 1994, both BATSE and Ulysses detected a bright GRB: its fluence (57-318 keV) was measured to be erg cm and its duration was roughly 90 seconds[7] The localization of this burst was ultimately reduced to an arc 80'' wide (3) and 5 degrees long (1). During the course of normal operations, the ETC collected and stored a full image of the error region of GRB941014 to the 2.5 level along its length 90 seconds after the end of the burst. Examination of the image (Figure 2) revealed no new optical source in or near the error region to a limiting magnitude of 10.2. The calculated upper limit on the ratio of optical to -ray fluence is .

  
Figure 2: ETC image of the error region of GRB941014: the image measures 20 x 15 degrees, with a pixel size of 3.1'. Stars as faint as V=10.5 are visible on this image. The thin arc encloses the error region of GRB941014: the dimensions of the arc are 10 long (2 error, as defined by BATSE) by 80" wide (3 error, as defined by the Interplanetary Network). In this image, the thickness of the arc is exaggerated for clarity: the actual 3 arc thickness is only 0.4 pixels.