On this page, we list the main changes that affected ERIS and this web site.

Observatory News

General news concerning the status of the obervatory and UT4 can be found here

Timeline of instrument status

The following table describes the events affecting the quality or the measurement of data obtained with ERIS. Its content can be downloaded as a Comma Separated Values file.

This timeline is complete as of August 22nd, 2022.

For each event, the Start Date column indicates when the event took place. Some events cannot be defined by a single instant, but extend over sometimes several days, weeks or months. Operation with the instrument may continue while the event occurs, in which case the Ongoing flag is set. If the event had ended, the Ongoing flag is lowered and End Date is given. The Type column indicates the characteristic(s) of the event: Earthquake, Maintenance, Upgrade, Element failure, Intervention, Pipeline installation at QC, Change of nominal values or thresholds, Modification of configuration file of this database, or Other. The Instrument Modes column indicates the affected mode. The column KPI lists the affected quality control parameters identified as Key Performance Indicators (i.e., parameters following the most critical quantities); the column non-KPI lists the other affected Quality Control parameters. The Calibration Raw Types column indicates the raw types of the affected calibrations. The Calibration Breakpoint flag indicates if calibrations obtained before the event cannot be used for science data obtained after the event or if calibration data obtained after the event cannot be used with science data obtained before the event. The Comment column provides more details on the event. The History column allows one to see possible past information on the entry.

The Quality Control pages for ERIS can be accessed through the QC overview page.


  • 05 Apr 2024: ERIS is again available for both service and visitor mode observations.
  • 30 Mar 2024: ERIS is unavailable for either service or visitor mode observations as it is being dismounted to investigate a leak discovered coming from above the instrument.
  • 30 Jan 2024: ERIS is again available for service mode observations.
  • 17 Jan 2024: ERIS is unavailable until the end of the month as it is being dismounted to investigate persistent problems with the AO periscope.
  • 11 Sep 2023: SPIFFIER is again available for service mode observations.
  • 15 Aug 2023: SPIFFIER is unavailable for service mode observations due to a technical issue with the grating wheel.
  • 13 Aug 2023: New modes/functionalities offered for P113:
    • NIX focal plane coronagraphy (FPC)
    • NIX long-slit spectroscpy (LSS)
  • 10 Mar 2023: An updated version of the ERIS ETC has been released (changelog).
  • 01 Mar 2023: New modes/functionalities offered for P112 (limits for approved P111 programs are not changed):
    • NGS AO limit changed from RP=1-11 to RP<11
    • LGS AO limit changed from RP=7-17 to RP=7-18, the BP<19 limit remains the same
    • Sparse aperture mask (SAM) interferometry
    • Non-sidereal and differential tracking
    • Seeing enhancer mode for targets without suitable tip-tilt stars
    • NIX windowing with four preset subarray sizes
  • 02 Dec 2022: ERIS science verification