SUMMARY OF PROPOSAL 41017
DR. SHUNJI KITAMOTO
FACULTY OF SCIENCE, OSAKA UNIVERSITY
OSAKA JAPAN 560
TOYONAKA
1-1, MACHIKANEYAMA-CHO

  E-mail: KITAMOTO@ESS.SCI.OSAKA-U.AC.JP	Tel: 06-850-5478	Fax: 06-850-5539
  Medium: 2.5GB8MM

Subject: STARS                                                       
  Title: STUDY OF X-RAY EMISSION MECHANISM OF O-STARS FORM TIME VARIATION                


Abstract:
 The X-ray emission mechanism of early type star is still unresolved problem. ROSAT
 observed an flare-up of zeta Ori, and they concluded that the X-rays are emitted by
 an expanding hot wind heated by a ploughing wind shock, from observed light curve.
 This conclusion might have some room for doubt. We propose to observe a time
 variation of zeta Ori and to study the temporal evolution of the plasma temperature
 and ionization parameters. This observation will provide rigid conclusion of the
 X-ray emission mechanism of early type stars.

 Co-Is:
   1  KEN'ICHI TORII      	OSAKA UNIVERSITY              JAPAN     
      TORII@ESS.SCI.OSAKA-U.AC.JP	06-850-5478
   2  TAKASHI TONERI      	OSAKA UNIVERSITY              JAPAN     
   3  HAJIME FUJIWARA     	OSAKA UNIVERSITY              JAPAN     
   4  YUKIO MATSUMOTO     	OSAKA UNIVERSITY              JAPAN     


Target Name           PRI RA        Dec        Time TC  Off GIS SIS_Cts  Obs
-------------------   --- --------  --------   ---- --  --- --- -------  ---
ZATA ORI               3   85.1900   -1.9400    40   N   Y   P  0.10000   4 

REMARKS:  IF POSSIBLE, 4 TIMES 20 KSEC OBSERVATIONS IS REQUIRED, DURING 4 SUCCESSIVE
          DAYS.
Monitored Oservation:
          Min. Int: 20.000  Max. Int: 80.000