NRO Heliograph Tohban's Report for Week 17 (20 Apr 1998 - 26 Apr 1998)

                                          Tohbans : J. Sato, T. Yokoyama

1. Solar Activity

     Solar activity was low. But an M1.4 flare on Apr 20 and
     an X1.2 flare on Apr 23 were observed. The latter was
     observed though the former was not because of the sunset.

2.  Remakable Events

 2.1  X1.2 flare on Apr 23

      EventID : nro_hg_19980423_0541
      Start : 1998-04-23 05:36:18
      Peak : 1998-04-23 05:41:39
      End : 1998-04-23 06:44:56#
      Peak Intensity (17GHz): 6976
      50mmsec Data Duration : 05:34:18 - 05:42:09, 05:55:06 - 05:58:05
      Position : S13E91 or S18E91(SXT PFI center)
      GOES : X1.2
      AR NOAA Number : 8210

    A limb event. LDE more than 4 hours.