NRO Heliograph Tohban's Report for Week 22 (25 May 1998 - 31 May 1998)

                                    Tohbans : H. Nakajima and K. Shibasaki

1. Solar Activity

   The Sun became active from May 27 when AR NOAA 8226 moved towards 
   the west limb. On May 27, a new active region (AR X) appeared in 
   the southern hemisphere on the west limb. Most of activities occurred 
   in AR NOAA 8226, and some activities occurred in the newly-appeared 
   active region, AR X.
   The most intense flare is a M-class flare which occurred on May 29. 
   We observed two jet-like eruption on May 28, and one prominence 
   eruption on May 31.
   We also observed a large quicent prominence near the south polar region.
   We probably had a chance to observe a large-scale magnetic field 
   structure of the prominence.

2.  Remarkable Events found by NRH

   2.1 M-class flare on May 29 (00:55 UT - 01:15 UT)
        
      This flare occurred in AR NOAA 8226 on the northern west limb. Almost 
      simultaneously the weaker microwave emission was observed in the active 
      region, AR X.

  2.2 Two jet-like eruptions on May 28

      Two jet-like eruptions were observed, one in AR NOAA 8226 from 00:56 UT
      to 01:15 UT and the other during 04:45 UT and 05:06 UT in AR X. 
      Brightness temperatures of both events were more than 15000 K, and 
      therefore these were not prominence eruptions.
 
   2.2 Prominence eruption on May 31 (23:15 UT - 23:18 UT)
      A promunence eruption were observed in AR X.