Dear ASCA users,

Please find below the ASCA observation schedule for the period from
July 8 to July 19, 1999. I have received a report on the malfunction of the 
SIS-1 Chip-2 from the SIS Instrument team. The chip is no more usable
for  observations. Fortunately it is not  the nominal chip for 1-CCD mode
therefore we can continue the nominal 1-CCD mode observation for SIS-1. 
No problem is for SIS-0. See the report from the SIS team attached below.

F. Nagase

 -----------------------------
 We stop using chip 2 of SIS-1.  
 -----------------------------
On May 27, duty scientists at the tracking station noticed strange behavior 
in one chip of one of the SIS. We immediately started investigation of the 
sensor and found that extremely large bright defects had developed in the 
frame-store region of chip 2, sensor-1. More than 80 % of the effective area 
in the chip is filled with leaked charge. We tried various methods, but could 
not recover the chip. We went back the SIS data, and found that the chip 
functioned normally on May 14, but was already damaged on May 25. Because the 
chip was not used between May 14-25, we could not identify the exact date 
when the defects first developed, nor have we identified the cause of the 
defects. We decided to stop using chip 2 of SIS-1. All the ASCA observations 
from now on should not use chip 2, SIS-1. Other chips of SIS-1 can be used 
as before.
							== SIS Team ==

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A S C A     WEEKLY  OBSERVATION   PLAN
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#17:  JULY 8 - 19, 1999			ver-1   (99/ 6/10)
(ISAS contact scientist: 	T. DOTANI 	(dotani@astro.isas.ac.jp)
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Date	MNV	Target 		Tag. 	Exp.	Observation	PI or 
	start	name 		Cat.	(ks)	Cat.  Pri./TC	 ( PPI/Co-PI)
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7/ 8	12:00	EV Lac		Star	80	ESJ	2/n	F. Favata
									
7/10	11:30	PDCS 01		CG	100	JPN	1/n	T. Tsuru

7/13	 4:30	MS 0147.8-3941	CG	65	US	1/n	P. Henry

7/14	23:30	G296.8-0.3	SNR	25	JUS	2/n	K. Torii

7/15	18:20	RX J0152-23	AGN	30	US	1/n	K. Leighly

7/16	17:00	PG 0052+251	Gal.	60	JPN	2/n	K. Hayashida

7/18	 5:20	RX J0323-49	AGN	30	US	1/n	K. Leighly

(7/19	 0:10  MNV to next target)
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(Note) Obs. Cat. JPN: Japan time, US: US time, JUS: Japan-US Collaboration, 
USJ: US-Japan Collaboration,  MJU: Merged Japan-US (PPI=Japan), 
MUJ: Merged US-Japan (PPI=US),  ESJ: ESA-Japan Program, 
MOT: Observatory Time (Calibration, maintenance), 
and TOO: Target of Opportunity