Timeline of instrument status

The following table describes the events affecting the quality or the measurement of data obtained with VIRCAM. Its content can be downloaded as a Comma Separated Values file. It is complete as of September 13th, 2020.

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 indicates which quality control parameters identified as Key Performance Indicators (i.e., parameters following the most critical quantities) are affected; the column non-KPI indicates which other critical Quality Control parameters are affected. 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. The History column allows one to see possible past information on the entry.

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

Announcements

• 2021-10-01 - 2021-10-10: Maintenance on VIRCAM/VISTA, so no operations will happen during those days.
• 2021-08-14: VISTA/VIRCAM have started operations again on August 13th, and data are delievered once again.
• 2021-03-25: Due to rising COVID-19 infections in Chile, Paranal is running with further reduced staff. As a consequence, VIRCAM/VISTA is not in operations until the staffing situation relaxes again.
• 2020-12-17: VIRCAM@VISTA has started regular science operations on December 15th. We're keeping an eye on the data, but have not yet found any significant issues.

VIRCAM history

 this section, we list the main changes that affected the instrument and this web site in the past, previous to the events log presented above (Sept 13th, 2020).
We also point at science results with the instrument

• 2023-02-03: VISTA is currently undergoing an intervention for the preparation of 4MOST. It is scheduled to be back in operations on Feb 27th and will operate until March 6, when VISTA will once again go out of opeartions for a mirror coating. VIRCAM is not scheduled to come back into science operations after this, so effectively is decommisioned on March 6, 2023.
• 2020-12-17: VIRCAM@VISTA has started regular science operations on December 15th. We're keeping an eye on the data, but have not yet found any significant issues.
  
• 2020-03-23: Due to the closure of Paranal Observatory due to the Coronavirus Pandemic, there will be no VISTA/VIRCAM observations for the forseeable future. VISTA has been closed since March 17 already.
• 2020-02-10: Since Jan 21st, no new affected images have been detected, we are confident that this means that the issue has been solved.
  For completeness, this table gives the IDs of all installed board at any given time. Boards marked in dark blue were/are spare boards, the board marked in red is the Sync Board Slae#2, which had 2 contacts re-soldered on Jan 21st. Unless we encounter further issues, we will leave the configuration as it currently is.
  

• 2020-01-21: The Sync Board Slave#1 and Slave#2 was replaced. These boards collect and combine the signals from 2 sets of IRACE readout boards (Chips 1-8 and Chips 9-16, respectively). 2 pins/connections were re-soldered on Sync Board from Slave2. After this change, all the boards in slave#2 except one associated with chips 13-16 are not the original ones.
• 2020-01-17: All 8 boards connected to Chips 9-16 where replaced with spares that use the same firmware.
• 2020-01-14: We have implemented a new, improved script to detect affected images and are confident that we have a high rate of detecting this issue now (but can not guarantee complete detection, PIs are adviced to check their data). We have further implemented a system to re-classify OBs shoudl these issues occur. The complete classification scheme can be found here (please notice especially the last VIRCAM bullet "Electronic readout failure classification rule"):
  • http://www.eso.org/sci/observing/phase2/SMGuidelines/ConstraintsSet.VIRCAM.html#InsSpec .
• 2020-01-13: IRACE boards connected to chips #9, #10, #11 and #12 have been replaced with spares, all with recent, and consistent firmware (but different to chips 13-16).
• 2019-12-15: Gigalink board on slave#2 rack that transmit the images from chips 9 to 12 was replaced by a spare. 
• 2019-12-15: Checking older data, we have noticed that the eletronic readout issue has existed since at least Jan 2018, although it happened much less often. PIs are adviced to check their data. CASU would catch most of the affected files, but especially PIs who do not received their data through CASU should have to check the data carefully.
• 2019-11-30: On Nov 30, the IRACE readout boards have been swapped back to their original configuration such that each board read out the same chip as before Nov16. We're further investigating and trying to find out which board is faulty.
• 2019-11-27: Further Update. With the swap of the boards ~10 days ago, it seems the issue has now also changed to Chips 1-8 (we detected several occurences on Chips 1-4, no further on Chips 9-16). We are in the process of running more tests and swapping out boards, hoping to remove the faulty item. Unfortunately, this approach is somewhat trial and error, so it might take us a while to fix the issue. We will monitor the situation closely and take appropriate actions when we see further occurences. On Saturday, Nov 30, we will also swap the readout boards BACK to their original positions, e.g. that the faulty board once again is situated at Chips 9 to 16, as this is the situation that most PIs will be more used to. 
• 2019-11-17 Update on this situation with swapped Chips. In September, we started monitoring this issue, which is surprisingly tricky to detect, especially given the sporadic nature of the issue. We have not detected many affected images for a while, but had individual nights where the images are affected by this or other IRACE readout issues. We have since improved the scripts to detect other effects than swapped chips (horizontal and vertical lines, for example), and am now routinely visually checking the images flagged up both by night and day. We have started re-classifying affected OBs, if users detect some of these issues, they are adviced to inform us. We also run an attempt to find these affected images in the past, e.g. to figure out when exactly this started and how many images are affected. In parallel, we have started working on the troubleshooting of the actual problem. On Nov 16th, we have swapped the IRACE readout boards in VIRCAM, such that the one that previously read out chips 1-8 now reads out 9-16 and vice versa. This will allow us to conclusively detect whether the board or another component is the culprit for these issues, and we will then take the appropriate measures to make sure that all data are usable. I will post an update when I have any news.
• 2019-08-30 We have recently discovered a eletronic issue on VIRCAM in which it occasionally happens that chips in individual VIRCAM images are swapped (e.g. chip15 is in place of chip16 and vice versa, can happen for other chips, too). This seems to come with other issues (e.g. areas of larger noise, stripy images along columns), but it seems possible that those issues can happen independently. Users are adviced to take care with the data at the moment, please check them carefully. We are investigating the issue and try to develop a way to at least detect the issue during operations. This has so far only been detected from dates after the recent VISTA intervention, but this also needs to be investigated further.
• 2019-08-04 After some further delay due to the weather situation and some issues during re-commissioning, VISTA/VIRCAM are back in operations as of Augst 4th 2019. Operations are basically back to normal, with the odd hickup after the major drive update, which is now routinely handled by the night crew. Sorry for the late notice.
• 2019-07-09 An Error on one of the VISTA M1 pads was encountered during the re-coating of M1. This needs to be fixed first, leading to delays in the re-mounting of the M1 mirror. We expect VISTA to be back in operations towards the end of July (2019).
• VIRCAM will be out of operations from May 5th to June 14th (drives update) and June 22th to July 12th (M1 re-coating), as is currently scheduled. 1 week of data will be taken in between, further/more detailed information will be made available here.
• 2018-11-24 VISTA is back in Operations.
• 2018-11-17 to 2018-11-23 - VISTA was undergoing an intervention on the secondary hexapod (and a drive test for the planned VISTA upgrade).
• 2018-08-07 - The VISTA primary mirror and the VIRCAM entrance window has been cleaned. This has lead to a significant improvement of the zeropoints (>0.1mag in all filters).
• 2018-06-28 - VIRCAM was out of operations on June  28 for Software tests.
• 2018-06-21 - VIRCAM was be out of operations from June 17 to June 25 (including) for a planned mainteance of the Closed Cycle Cooler.
  
• 2017-03-27 - The VIRCAM interventions went smooth and quicker than expected, so we got VIRCAM back into science operation a few days early. Data is checked carefully for artefacts in the first few days.
• 2017-03-21 - VIRCAM is currently down due to a (scheduled and regular!) maintenance of the Closed Cycle Cooler (~10 days). After this, there is a (again: scheduled) intervention for installation and testing of new drives for the telescope for an upcoming telescope upgrade (~8 days). After a night of verification and change of period, VIRCAM/VISTA is scheduled to be back in operations on April 1st. 
• 2016-02-05 - The response in the upper half of chip #16 has decreased after the intervention in Nov 2015. The effect is more pronounced in the Z band, and to a lesser extent in Y, J and the narrowband filters. Before the intervention, the fractional response in the upper half was ~50%-70% in Z. After the intervention it has decreased to ~40%. This issue is under investigation.
  
• 2015-12-04 - VIRCAM fully back in operations.
  
• 2015-12-02 - VIRCAM finishing cool down process. Some technical time at the beginning of the night to check dark current, then service observations. In the following 3 nights at least part of the night time will be used for a software upgrade.
  
• 2015-11-20 - Start of VIRCAM cooling system maintenance, to be followed by a software upgrade. VIRCAM will be back into operations on Dec 5.
  
• 2015-08-27 - The VISTA User Manual for P97 was uploaded.
• 2015-08-01 - A Call for Letters of Intent for new public surveys with VISTA was released.
• 2015-06-26 - VIRCAM back to normal operations. Detector temperatures are normalised and stable.
  
• 2015-06-23/26 - VIRCAM back in operations. Detector temperatures are 1.5 deg higher from nominal 72K, causing changes in flat-fielding fluxes to a <5% level. Calibrations taken between nights 2015-06-23/26 should NOT be used to calibrate data taken outside this time window.
• 2015-06-12/23 - VIRCAM out of operations due to warmup-cooling cycle after Paranal power cut
• 2014-08-25 - The VISTA User Manual for P95 was uploaded.
• 2014-07-15/24 - 10 nights of Close-Cycle-Cooler maintenance
• 2014-06-09/14 - 6 nights of software upgrade and testing
• 2014-03-06/09 - 4 nights of technical time loss due to M2 problems.
• 2014-03-01 - The VISTA User Manual for P94 was uploaded.
• 2013-10-01 - Start of P92 (including various carry-over observations).
• 2013-09-12 - Press release: The Peanut at the Heart of our Galaxy
• 2013-04-01 - Start of P91 (including various carry-over observations).
• 2013-02-20 - Press release: Sweeping the Dust from a Cosmic Lobster. New infrared VISTA image of NGC 6357
• 2012-12-20 - First night of nominal observations after the end of the Cryo-Cooler maintenance.
• 2012-12-08 - Start of the Cryo-Cooler maintenance, no observations
• 2012-10-24 - Press release: 84 Million Stars and Counting. VISTA creates largest ever catalogue of centre of our galaxy
• 2012-10-01 - Start of P90 (including various carry-over observations).
• 2012-11-20 - Start of the VISTA building extension works.
• 2012-05-09 - Press release: VISTA Views a Vast Ball of Stars
• 2012-05-05 - VISTA underwent an intervention M2 unit from May 1 to 5, 2012, to exchange a hexapod leg. The telescope is back in normal operation.
• 2012-04-01 - Anticipated start of P89 (including various carry-over observations).
• 2012-03-21 - Press release: VISTA Stares Deep into the Cosmos
• 2012-01-19 - Press release: The Helix in New Colours
• 2011-12-20 - VIRCAM underwent an intervention for routine Closed-cycle Coolers' maintenance from 2011-19-10 to 2011-19-20. The instrument is back in operation.
• 2011-10-19 - Press release: VISTA Finds New Globular Star Clusters
• 2011-09-10 - The VIRCAM entrance window was cleaned. The effect to the users is somewhat lowered background.
• 2010-09-01 - Messenger article by Petr-Gotzens et al: Science Results from the VISTA Survey of the Orion Star-forming Region
• 2011-08-04 - Messenger article by Cioni et al: The VISTA Near-infrared YJKs Public Survey of the Magellanic Clouds System (VMC)
• 2011-08-03 - Press release: VISTA Finds 96 Star Clusters Hidden Behind Dust
• 2011-05-05 - VISTA has been taking data for a few days already, andas of 2011-05-04 the telescope is back in normal operation. The image quality is excellent, and the sensitivities are as expected for aluminum covered mirrors. More details will be provided on the VIRCAM@VISTA web page shortly.
• 2011-03-14/2011-05-04 - Extended VISTA recovery period. A seriousmechanical problem detected during the re-coating intervention requiresan extended repair and preventive maintenance period. The VISTA telescope is expected to undergo on-sky tests by May 3/4, 2011.
• 2011-04-07 - Start of P87 (and restart of P86 carry over observations)
• 2011-03-04/2011-04-06 - Technical Time: Recoating of M1 and M2 with aluminium. The reflectivity of the silver coatings of M1 and M2 hasdegraded very quickly. Based on sample mirrors placed in various placesof the observatory it was decided to select this time an aluminum coating, rather then the more quickly degrading protected silver coatings.
• 2010-11-25 - Messenger article by Saito et al: VISTA Variables in the Vía Lactea (VVV): Current Status and First Results
• 2010-10-06 - Press release: VISTA Reveals the Secret of the Unicorn
• 2010-10-01 - Start of P86
• 2010-08-31 -  1st call for regular ESO proposals at VISTA  for period 87 (April to September 2011). In period 87 at least 75% of the time will be reserved for public surveys.
• 2010-08-21 - Technical time: Horizontal re-centering of VIRCAM
• 2010-07-16 - Press release: VISTA Views the Sculptor Galaxy
• 2010-07-01 - The VISTA User Manual was updated for the phase 2 preparations of the P86 service mode observation projects
• 2010-06-16/2010-06-20 - Technical time: M2 improvements,replacement of the defect altitude gyro, which has since May causedlarger image elipticity.
• 2010-04-24/2010-05-06 - Technical time: Instrument warm-up, camera shim replacement, helium line cleaning, and other activities
• 2010-04-21 - Press release: VISTA Captures Celestial Cat’s Hidden Secrets
• 2010-03-31 - Messenger article by Arnaboldi et al: VISTA Science Verification - The Galactic and Extragalactic Mini-surveys
• 2010-03-31 - Messenger article by Emerson and Sutherland: The Visible and Infrared Survey Telescope for Astronomy (VISTA): Looking Back at Commissioning
• 2010-03-31 - updated Links with the VISTA Surveys Progress and QC as provided by CASU
• 2010-02-10 - Press release: Orion in a New Light
• 2009-12-21 - Updated VISTA Science Verfication page - the raw data and some reduced data were made public together with the description of the data.
• 2009-12-18 - The VISTA User Manual was updated for the phase 2 preparations of the P85 service mode observation projects
• 2009-12-11 - Press release: VISTA: Pioneering New Survey Telescope Starts Work;provisional acceptance of VISTA by ESO. Meanwhile, since November 4,2009, VISTA has started to obtain "early science" data for the public surveys.
• 2009-10-16/30 - the VISTA Science Verification took place. The weather cooperated, and the approved programs were executed nearly completely.
• 2009-09-24 - All pages were updated to include the informations,user manuals and tools required for the preparation of the upcoming Science Verification Run and the Public Survey "Dry Runs".
• 2009-09-18 - The mirrors have received a new silver coating in the past week. After reinstalling the components and recalibrating the systems we will start the Science Verification phase between October 16 an 30, 2009. A fact sheet with a preliminary summary of the performace was add to the instrument page
• 2009-06-18 - Only minor updates, The VISTA WEB pages are now linked from the ESO science WEB
• 2008-09-12 - The VISTA User Manual is now available for the public survey workshop
• 2008-09-11 - The VISTA science verification page was created
• 2008-09-11 - The public survey WEB page was updated
• 2008-09-11 - The p2pp User Manual is now available for the public survey workshop
• 2008-06-24 - ESO Public Surveys Phase 2 Workshop, Sept. 15-17, 2008
• 2008-06-21 - First night of commissioning with camera on sky
• 2008-04-16 - Paranal Receives New Mirror - Survey telescope nears completion