A GIGANTIC CORONAL JET EJECTED FROM A COMPACT ACTIVE-REGION IN A CORONAL HOLE

A gigantic coronal jet greater than 3 x 10(5) km long (nearly half the solar radius) has been found with the soft X-ray telescope (SXT) on b oard the solar X-ray satellite, Yohkoh. The jet was ejected on 1992 Ja nuary 11 from an ''anemone-type'' active region (AR) appearing in a co ronal hole and is one of the largest coronal X-ray jets observed so fa r by SXT. This gigantic jet is the best observed example of many other smaller X-ray jets, because the spatial structures of both the jet an d the AR located at its base are more easily resolved. The range of ap parent translational velocities of the bulk of the jet was between 90 and 240 km s-1, with the corresponding kinetic energy estimated to be of order of 10(28) ergs. A detailed analysis reveals that the jet was associated with a loop brightening (a small flare) that occurred in th e active region. Several features of this observation suggest and are consistent with a magnetic reconnection mechanism for the production o f such a ''jet-loop-brightening'' event.