1.Status of the preparation toward the Open-Use operation at the Subaru Telescope:

The focal units of the telescope have been set up and calibrated using experimental observational instruments since Subaru's First Light last January. As you know, the Subaru Telescope has already released to the public some significant scientific data, which were acquired earlier.

Recently, as observational instruments for the first generation become ready for testing, the Subaru Telescope conducted joint observations with the observational instrument development groups to test the performance of these instruments. Based on these situations, and with the approvals of the Optical and Infrared Astronomy User's Meeting and the Advisory Committee for Subaru Telescope, we have been preparing to start sharing telescope time with other researchers for the Open-Use operation as from October 2000. As of today, test observations have been conducted with six observational instruments, COMICS, IRCS, CIAO, FOCAS, Suprime-Cam, and OHS. Although these observational instruments are still in their initial set-up stage, we were able to confirm their high performance in observational quality with the telescope. HDS and AO are currently being prepared for their functional tests.

After assessing the current status of preparation and also considering the scientific merits for the Subaru Telescope, we are planning to start the Open-Use operation with only two observational instruments, IRCS and Suprime-Cam, in the latter half of this year.

2. Starting date for the Open-Use operation:

Because the Subaru Telescope is a large and complex system integrating the optics, mechanical units, and computer controls, it is very difficult to foresee all possible situations and set a firm schedule for operations. As for example, a trouble arose at the end of March of this year with the fixed point of the primary mirror. Analysis of the trouble, finding a solution and implementing preventative measures to the system took more time than expected: While this trouble did not affect the accuracy of the mirror surface and its observational performance, it occurred to a critical component of the telescope, which required prudent recovery measures. So at this time, it is very difficult to stay with the original schedule for the Open-Use operation planned for October 2000. Consequently, we would like to postpone the starting date for the Open-Use operation to December 2000 at the latest. We ask for your understanding regarding this matter. However, mailing of the request forms for the Open-Use will start immediately.

We apologize for the inconvenience to all of you who have been preparing for the Open-Use observation Again, we would like to ask for your understanding regarding the situation during the commissioning phase of the Subaru Telescope, which strives to provide the highest telescope performance in the world.

Technical reports providing details on the initial defects of the telescope including the trouble with the fixed point will be presented at the Advisory Committee for Subaru Telescope on June 30.