ESPaDOnS
instrument status


Official status

Quoting the Memorandum Of Understanding (MOU) signed between CFHT and OMP, ESPaDOnS was developped to become a guest instrument, ie an instrument developped by an institution other than CFHT and operated/maintained by the CFHT staff during the time the instrument is available to observers at CFHT. The status of guest instrument is only awarded once: If any of these conditions were not met (or at least agreed upon by both CFHT and OMP), the MOU specifies that ESPaDOnS will have the status of a visitor instrument (ie operated and maintained by the owners without significant CFHT support) until all problematic issues are settled.

Acceptance tests

Initially planned for January 2004 then postponed to the end of March 2004 (due to problems in fabricating the specific fibre bundles), acceptance tests were again postponed to an unspecified date by the CFHT staff on the argument that the control software of ESPaDOnS was still very unreliable and contained a large number of major bugs. Given the fact that the OMP team did not agree with this diagnosis, it was proposed that ESPaDOnS was used as a visitor instrument (following the suggestion explicitely included in the MOU), to allow the community benefit from the unique capabilities of ESPaDOnS as early as semester 2004B.
A total of 16 different proposals were submitted along these lines to both French and Canadian TACs, asking for a total of about 60 observing nights for carrying out scientific programs focussed on various issues (from stellar magnetic fields and activity phenomena to extrasolar planets, from stellar pulsations to circumstellar environments and interstellar media). All these proposals were simply rejected by CFHT authorities on the argument that ESPaDOnS had not been tested on the sky and could thus not pretend to the 'visitor instrument' status. The OMP team deeply regrets this decision, that was taken without even attempting to evaluate quantitatively both the risk and the scientific impact associated with proposing ESPaDOnS to the community as a visitor instrument as early as semester 2004B.

Acceptance tests were finally carried out between May 24 and June 4 2004, ie almost immediately after the 7th CFHT Users' Meeting and the associated meeting of the CFHT Scientific Advisory Committee (SAC). During this 2 week period, ESPaDOnS was thoroughly tested, not only for the reliability of its harware and software control system, but also for its capacity at matching the instrument specifications initially aimed for. A number of issues were reported and/or evidenced during these tests, to be fixed by either CFHT (for problems concerning material provided by CFHT such as the dewar, CCD detector and associated software detector control) or by OMP (for all other problems). Given the fact that all these issues were mostly minor, the CFHT staff in charge of the acceptance tests decided that ESPaDOnS successfully passed the acceptance tests at OMP and could be shipped to CFHT.

Shipping and installation at CFHT

Once all minor issues evidenced during the acceptance tests were fixed, ESPaDOnS was dismounted and securely packed on June 24-30, then brought to Amsterdam on an antivibration truck with airconditionning on July 1st, to be shipped to Hawaii by airplane cargo on July 2. It arrived in Honolulu (custom cleared) on July 8 and was brought up to the big island, then to CFHT by truck, where it arrived on July 12 in perfect condition.

Installation at CFHT took place between Aug 2 and Aug 20 2004, and was achieved by 4 members of the OMP team with help from the local CFHT staff. Once remounted, the instrument performances were identical as those obtained at OMP.

Technical nights and science verification time

A total of 6 technical nights were scheduled for testing ESPaDOnS on the sky. The first engineering run took place on Sep. 2/3, 2004. The nights were very clear with a bit of cirrus. ESPaDOnS behaved very well; after only about an hour for setting up guiding issues, we could start stellar observations so that first light occured at about 8:00 UT on Sept. 3. Apart from a few minor issues, everything was found to match expectations. As a result, it was decided that ESPaDOnS could be offered to the general community as a guest instrument starting semester 2005A. The second and third engineering run (respectively scheduled on Sep 22-23 and Nov 28-29) confirmed these results.

A total of 5 science verification nights were allocated on 2 scientific programs, and were scheduled on Nov 30-Dec 2 2004, and Dec 21-22 2004. The first chunk of time (first program) was about half cloudy, while the second chunk (second program) was almost completely clouded out. A magnetic map of a star was derived from these ESPaDOnS data, demonstrating that the instrument can reach the typical goals for which it has been designed.

Availability to the general community

ESPaDOnS is open to the general community since semester 2005A.



© Jean-François Donati, last update Nov 16 2005