On this page, we list the main news/changes that affect the instrument and telescope and point at science results with the instrument

Timeline of instrument status

The following table describes the events affecting the quality or the measurement of data obtained with OMEGACAM. 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 OMEGACAM can be accessed through the QC overview page
Announcements
2021-05-06. VST back in operations.

2021-04-29. Vacuum problem with OmegaCAM. The instrument had to be warmed up as is currently not in operations.

2021-04-21. OmegaCAM is back in operations.

2021-04-21. OmegaCAM bas been undergoing annual maintenance since 2021-04-14. News pages will be updated when it is it back in operations.

2021-12-17. OmegaCAM will remain in operations until 30th September 2022, completing programmes carried-over from earlier periods. The only new proposals to be accepted will be for Director's Discretionary Time (DDTs).

2021-09-08. OmegaCAM will be out of operations from 10th to 20th September 2021.
2021-09-08. The pointing of OmegCAM in azimuth was degraded from 2021-Jan-06 to 2021-Sept-07 with differences between the actual pointing and WCS up to around 40 arcseconds over the 1 degree field of view.

2021-08-31. The operations agreement for VST terminates on 31st March 2022.

2021-08-14. OmegaCAM is back in operations, still with the problems with CCD numbers 69 and 77.

2021-07-29. The problem with CCD#77 (and likely #69) has been determined to be located inside the cryostat. It is not clear if and over what timescale an intervention could occur to fix these issues.

2021-07-29. OmegaCAM is still out of operations.

2021-07-02. Recall that from 05-Jul-2021 the contact point for questions concerning service mode observations has changed from usd-help@eso.org to https://support.eso.org

2021-07-02. OmegaCAM is still out of operations. More news when there is any. CCDs 69 and 77 still have problems.

2021-06-02. OmegaCAM is still out of operations. More news when there is any.

2021-05-19. OmegaCAM user manual updated.

2021-05-13. OmegaCAM is still out of operations

2021-04-15. Attempts to fix problems with CCDs-69 (very high dark level and bright spot) and 77 (CCD unresponsive) have so far not been succesful. More news when available.

2021-04-15. Since 24-March-2021 OmegaCAM has been out of operations due to Paranal observatory reducing staff because of Covid-19. Change of period night time tasks are thus still pending.

2021-02-12. User manual updated.

2020-12-09. User manual updated.

2020-11-26: The operation agreement for VST has now been extended by 6 months until 31st March 2022 to compensate for the loss of some 6 months of survey time because of COVID-19.

2020-11-19: OmegaCAM is back in operations, but currently without CCD 77 which is one of the CCDs close to the centre of the mosaic. Service mode users will be contacted to determine the effect of this on their science.  Observations will be graded "B" instead of "A" until the problem is fixed. The news page will be updaed in the event that the detector is recovered.

2020-09-02: OmegaCAM operations still halted. For general news please see www.eso.org/sci

2020-05-11: OmegaCAM operations still halted. Manual for P106 phase 2 released with no changes compared with P105 phase 2.

2020-03-23: OmegaCAM operations have temporarily halted along with operations for all other Paranal instruments. News will be posted when OmegaCAM is again operational.

2020-02-28: No changes for the call for proposals for phase 1 of P106.

2019-12-13: The OmegaCAM manual has been release for phase2 of P105. Minor changes.

2019-11-14: The OmegaCAM tools page was updated to clarify how PIs of programmes can have their data reduced by CASU.

2019-04-27: OmegaCAM back in operations.

2019-04-24: OmegaCAM out of operations due to an issue with the VST. News will be updated when OmegCAM is back again.

2019-04-23: OmegaCAM back in normal operations.

2019-04-15: OmegaCAM annual maintenance takes place between 14th-23rd April 2019.

2019-03-11. Starting 1st April 2019, the polar standard field will only be taken once a night and only when the sky conditions are clear or photometric.

2019-02-27. OmegaCam manual released for phase1 of P104. No changes with repect to P103.

2018-08-30. Normal, Monitoring and Large Programme proposals will be accepted for OmegaCAM for Period 103 without restrictions on atmospheric conditions, lunar phase or RA range.

2018-08-30. OmegaCam manual has only minor changes for phase1 of P103

2018-06-28. OmegaCam manual updated for phase2 of P102.
2018-06-28. PIs of approved Target of Opportunity observations will be contacted and informed about a new mode of ToO triggering using  p2.

2018-04-01. VST will now operate using a zenith avoidance distance of 7 degrees. This reduces the probability of suffering from images affected by ellipticity.

2018-02-26. OmegaCam manual updated for phase1 of P102.

2017-12-26. For P101 please check the following page concerning the creation of SM OBs for OmegaCam: https://www.eso.org/sci/observing/phase2/p2intro.html

2017-12-17. OmegaCam manual updated for phase2 of P101.

2017-11-01. Further checks showed that before the intervention the offset between UCAC2 and the OmegaCAM WCS was from 6-26 arcseconds (N=10), median value of 12 arcseconds and after the intervention from 9-26 arcseconds (median value 16 arcseconds). Hence no action was taken.

2017-10-24. Since the intervention there has been an issue with the coordinate system of OmegaCam which is offset by approximately one arcminute compared with the pre-intervention valus. Coordinates in the FITS headers are incorrect. The problem will be fixed as soon as possible. See above.

2017-09-28. OmegaCam is back in normal operations. Standard stars taken in the SDSS filters u,g,r,i,z and ugri indicate that the zero points are unchanged compared to before the intervention. Service mode operations resumed on the night of 2017-09-27 with most observations classified as "A".

2017-09-24. Intervention ongoing with OMEGAM to fix filter exchange issue. Intervention started 2017-09-16. Likely first night on sky for testing will be on 2017-09-27. See here for some images of OmegaCam dismounted from the telescope.

2017-08-30. Phase 1 Manual release. Minor change only. See ESOs call for proposals https://www.eso.org/sci/observing/phase1.html

2017-08-10. Continuing problems with the filter exchange unit of OmegaCam mean that filter exchanges can only be performed at the zenith. This will impact operations until a planned intervention of around 2 weeks is performed in the middle of September 2017.

2017-07-02 Phase 2 Manual released. Only change concerns minimum exposure time of OmegaCam. Still pending analysis are the full results of the comparison of the u-band flux with the exposure time calculator as indications are that the ETC over-estimates the flux in this band. This news page will be updated at the end of August with the final results.

2017-02-27 Technical data have recently been taken to measure the possible impact of the 4 laser guide star facility on Paranal upon OmegaCam observations. More news for Phase 2 of P100. Tests in January were also performed to investigate ellipticity of OmegaCam depends on distance to the zenith, length of tracking with no guiding etc. Results should also be made available for phase 1 of P101.

2016-12-10 Manual updated for P99 Phase 2. Minor changes.

2016-07-04 Manual updated for P98 Phase 2. Minor changes.

2016-05-18 OmegaCAM was out of operations for maintenance during five nights, until 2016-05-22.

2015-04-30 A set of baffle with a complete redesign of the inner ribs to reduce oblique reflections have been installed. All data taken starting this night has much reduced reflections and scattered light.
2015-04-28 Due to an improperly seated connection, CCD#73 had the images inverted throughout the night. Data taken within constraint were classified as B.
2014-12-05 to 2014-12-08 VST was out of operations for a technical intervention: technical inspection of the M2 Hexapod.
2014-10-25 a preliminary catalogue of secondary standard stars is available for download from the tools web page.
2014-09-08 to 2014-09-13 VST was out of operations for 6 nights to allow ESO staff at Paranal to work on the M2 unit whose correct functioning has been compromised in recent weeks.
2014-08-26 to 2014-08-30 a techimncal intervention was needed in order to remove a loose part inside the
the cryostat vessel of OmegaCAM. The observing constraints from 2014-07-07 can be now removed and VST operates normally. 
2014-08-16 VST is back to normal service.
2014-08-08 Stating from the night of 2014-08-07/08 VST is out of operation for a technical intervantion aimed at repairing the adaptor rotator and TCCDs. VST is expected to be back on operation on the 15th of August. 
2014-07-07 On the 04th of July during daily inspection of the telescope, an anomalous noise was heard coming from inside the OMEGACAM's cryostat. For precaution VST was kept out of service on the nights of 04-05 and 05-06. Operations are now resumed with contraint to not observe at zenith distances above 60 deg (allowed exception: polar field for calibrations). An inspection of the cryostat will be perfromed on mid of July.    
2014-05-30 to 2014-06-08 VST was out of service (9.5 nights) due to a damage to the co-rotator driver. After technical intervention the VST is back to normal operations. 
2014-04-26 VST is back to normal service.
2014-04-23 VST out of service due to a problem with M2 Leg#1: the actuator 1 reached the Hardware Lower Limit HLL. Technical intervention to solve the problem is ongoing.
2014-04-06 The installation of the baffle is completed. Unfortunately the science data taken on the first night after the baffle installation were affected by reflections due to the inner plug of the M1 baffle modifications. On the 7th a non reflecting adhesive tissue was installed and the problem was solved.
2014-03-27 The M1 was washed. This resulted in an improvement of ~3.8% in the mirror's reflectivity.
2014-02-02 VST was out of service due to abnormal torque distribution on the azimuth axis range. After technical intervention the telescope was back to normal operations on the night of the 7th.
2014-01-08     Change of flat field morphology due to installation of improved baffling on the VST. The new baffling reduces the effect of stray/scattered light in sky flats and from the moon. A final additional piece of baffling is planned to be installed in February, which will again lead to a change in flat field morphology.
2013-12-05     System throughput drop by about 0.6% within a few days early December, due to dust. Stable since then.
2013-11-20     Small bias level changes in chips 73-76 due to a video board exchange. (Chip 73 was showing occasional strong read out stripes).
2013-11-13 to 2013-11-17 Early technical tests of an enhanced image analysis algorithm, which would use aberrations measured on the science array to complement the intra- and extra-focal measurements on the auxiliary CCDs.
2013-07-21 to 2013-07-25 OmegaCAM was out of operation for 4 nights due to a intervention on VST technical CCD, adapter, and ADC. Not all planned work could be completed and another intervention is foreseen in the next months. Meanwhile VST and OmegaCAM are back to normal operations.
2013-05-07 to 2013-05-13 OmegaCAM was out of operations for six nights due to a cooling leak, which is now recovered and the instrument back on sky as of the night of May 13th.
2013-03-29 to 2013-04-01 OmegaCAM was out of operations for four nights due to a failure of the corotator-rotator alignment which required several days of repair work, both on VST and OmegaCAM side. The system is fully back in operations since 2013-04-02.
2013-03-24 to 2013-03-28 Temporary change in sky flat morphologies due to technical tests with improved baffling. The nights March 24/25 and March 25/26 had one set of additional baffling, the nights March 26/27 and March 27/28 had a different kind of additional baffling. Sky flats taken in the twilights of March 24/25 and March 25/26 are to be used only for science taken on those two nights, analogously skyflats taken in the twilights of 26/27 and March 27/28 are to be used only for science taken in these two nights. As of March 28/29, the baffling was removed and sky flats can be used again to calibrate data taken also before March 24/25. The same applies to dome-flats.
2012-12-05     System throughput increased by 5% due to washing of M1. For science data taken as of December 5/6, 2012, please use flat and standard calibrations taken as of Dec. 6.
2012-11-25     A software update was installed that gets rid of the previously occuring interference noise patterns on science images.
2012-09-12     The BIAS level of Chip 96 was increased from 380 to 650 ADU, to avoid that negative crosstalk from very bright stars in Chip 95 'inversely saturates' the detector at 0 ADU.
2012-09-06     See note in the ESO Call for Proposals for Period 91, Sect. 6.14: filler proposals asking for relaxed observing conditions are especially encouraged (Full Moon, Thin Clouds, Seeing). Possible science cases include proper motion studies, photometric monitoring in single fields, and generally accumulating photons in pre-calibrated fields.
2012-09-01     About 2 nights technical time used by INAF for porting the VST Telescope Control System to the most up-to-date VLT Software version.
2012-07-05     The Illumination Correction Report of the OmegaCAM consortium is available at the bottom of the Manuals section of this webpage.
2012-06-07     Update on Chip 82. On June 2, 2012, the video board connected to Chip 82 was exchanged. Preliminary results show that this has fixed the gain variations. Furthermore, the average gain in terms of ADU/e- has increased by 5 percent (i.e. five percent more flux in flat fields). The video board settings were adopted to not affect the gains of chips 81,83,84 which are controlled by the same board. Note to users : for calibrating chip 82 data taken as of night June 2/3, use only calibrations taken as of June 3 onwards. To be on the safe side, this should also apply for chips 81,83,84, although as mentioned above their gain has remained constant, to within better than 1 percent.
2012-05-09     Note on Chip 82. As mentioned in the OmegaCAM user manual, CCD#82 shows day-to-day gain variations of a few percent, since start of operations. Please be aware of this instability, which occasionally manifests itself in the form of pronounced horizontal step patterns.
2012-03-22 to 2012-03-31 There was an increased occurence of image quality degradation, likely due to a focal plane tilt. About 15 hours of science observations have had to be repeated. The situation has improved after changing M2 positioning parameters, but the root cause is still under investigation.
2012-02-03 to 2012-02-08 Six nights downtime due to OmegaCAM vacuum problem. No significant changes of detector performance have been spotted within the two weeks after recovery. Nevertheless, it is advised that calibrations from after Feb. 8 are not applied blindly to data from before Feb. 3. Please contact usd-help@eso.org in case of doubts.
2012-01-27 to 2012-02-03 A total of 2 nights technical time to work with consortium on OmegaCAM Software action items remaining from PAC.
2012-01-17 The measured seeing distribution on OmegaCAM images from August to December 2011 is linked under the Tools section.
2012-01-06 to 2012-01-10 Successful VST intervention by Paranal engineering for repair and maintenance of rotator brakes, encoders and cooling system.
2011-12-22    Updated version of User Manual and Template Manual for P89 Phase II. See Manuals Page
2011-12-15    Press Release on Science Verification imaging of the spiral galaxy NGC 253.
2011-12-05 to 2011-12-12 VST intervention by INAF to work on remaining Action Items after PAC.
2011-11-05 Preliminary Acceptance Chile is officially granted to VST, retroactively for October 15.
2011-10-15 Official Start of Science Operations, P88
2011-09-14: Updated versions of User Manual and Template Manual, to be used for P88 Phase 2 and for P89 Phase 1. See Manuals Page
2011-08-29 to 2011-09-04: Science Verification, targetting NGC 253 in u+g+r+i and Halpha (NB659).
2011-08-13: Start of Public Surveys with Early Science and Dry Runs in parallel to technical activities
2011-07-28 to 2011-08-12: OmegaCAM commissioning 3
2011-07-13: First Version of Template Manual available from the Manuals Page. Name of User Manual document changed to be in line with ESO standards (no change in contents).
2011-06-29: First version of User Manual available from the Manuals Page.
2011-06-08: Press Release 'First Images from the VLT Survey Telescope'
2011-06-06 to 2011-06-22: OmegaCAM commissioning 2

2011-04-29 to 2011-05-09: OmegaCAM commissioning 1b

2011-03-21 to 2011-03-31: OmegaCAM commissioning 1a