News for P111 (Apr 01, 2023)

  • August, 2023: During the night of August 17th, there was a failure with one of the detector cold heads of VISIR and it was necessary to start a controlled warmup of the instrument. The cold head maintenance as well as an adapter intervention, both originally planned for later in the year, will now be carried out in September. The plan is to have VISIR back in operations early October 2023 for P112 observations.
  • July, 2023: VISIR had to undergo a further thermal cycle between June 17th and July 11th due to technical activities on the UT2 M1 cell, which required VISIR to be disconnected from the power. The instrument was successfully verified on sky during the night of July 10th and is back in operations since then.
  • May, 2023: VISIR has been successfully recommissioned after the UT2 M1 recoating and is back in operations since May 17th. It seems that with the freshly coated telescope, mid-infrared background levels measured by VISIR have decreased.
  • Apr, 2023: VISIR has been detached from UT2 due to the recoating of M1 of UT2. The cool-down and recommissioning is planned for mid May 2023.
  • Mar, 2023: Due to the very low demand of observations with VISIR, it has been proposed to decommission VISIR in the near future. The decommissioning may take place as early as the end of P115 (Sept. 2025), i.e. significantly before the arrival of CUBES, which will occupy the Cassegrain focus of UT2 currently used by VISIR.

News for P108 (Sept 16, 2021)

  • Feb, 2022: Since VISIR has been attached to UT2, the background levels for various filters have changed w.r.t. the values on UT3. Most negatively affected are the background levels of the B10.7 and J7.9 filters. For the B10.7 filter, count rates due to the background have increased to above the linearity range (<40000 counts), essentially making observations with this filter impossible; for J7.9, count rates are very close to this limit. As an immediate solution, the DIT for the often requested B10.7 filter will be reduced to 0.0066s, which in turns implies a windowing of the detector to 512 pixels in y-direction. As a result of the increased background, also the sensitivity has deteriorated slightly, such that – for the time being – the offered sensitivity for the B10.7 filter will be increased slightly to 5mJy 10σ/h. Based on the still limited number of sensitivity measurements with VISIR at UT2, no other filter shows a clear advantage over the B10.7 filter in terms of sensitivity.
    A more detailed investigation is still ongoing. An update of the sensitivities for VISIR at UT2 is being carried out by accumulating sufficient statistics of standard star measurements.
  • Oct, 2021: Observations with VISIR in Service Mode have resumed.
  • Aug-Sept, 2021: VISIR has successfully been installed on UT2 at the beginning of August. The commissioning is on going and we hope to have the instrument ready by the beginning of P108.

News for P107 (Apr 01, 2021)

  • Mar 02, 2021: VISIR is foreseen to be mounted in UT2 during P107 and it is expected to have the instrument available by the end of July.

News for P106 (Oct 01, 2020)

News for P105 (Apr 01, 2020)

  • Dec 20, 2019: It has been decided that VISIR will be moved to UT2 starting P105.
  • Sep 01, 2019: The call for proposal for P105 is out. VISIR is offered in all its capabilities.

News for P104 (Oct 01, 2019)

  • Jan 18, 2020: VISIR is removed from UT4 and is unavailable for the rest of P104. It will become available again on UT2 starting P105
  • NEAR Science Demonstration deadline for proposal submission is 7 August 2019. Details are given here.
  • Joint VISIR & ALMA observations reveal Uranus' glowing rings. Press release from ALMA observatory.
  • ESO press release on the progress of the NEAR experiment. The data from the NEAR experiment are publicly available from the ESO archive under programme ID 2102.C-5011.
  • Regular (non-AO) VISIR will be offered for regular operations at the cassegrain focus of UT4, albeit  limited in its capabilities compared to regular UT3 operations:
    • Observations can be done in M-band and N-band, but not in Q-band as a result of the NEAR dichroic that picks up the light for the AO module
    • A fixed chop throw of 6” which is due to the Deformable Secondary Mirror of UT4
  • The use of VISIR in its NEAR configuration is not offered for regular operations, but the possibility of further scientific exploitation of this experimental mode in a limited, dedicated campaign is under consideration. Such campaign would be open to the community through a special call amd will be announced in the ESO Science Announcements and the Science Newsletter as well as on the VISIR public pages.
  • M-band news: The necessary intervention to modify VISIR for NEAR has allowed to correct the red light leak of the M-band filter by means of a blocker.
  • During P104 VISIR is foreseen to move back to UT3. The exact date depends on various factors and is not settled upon yet.
  • Large programs on VISIR can be requested, starting in P104, albeit with the restrictions imposed by UT4 operations as mentioned above

Older news

  • Sept 28, 2018: It has been brought to our attention and it has been verified that the VISIR M-band filter suffers from a red leak which peaks at 11.9 micron and reaches about 25% transmission. This leak will contribute significantly for targets with rising spectra towards the red; M-band transmission curve. For more information please contact
  • Sept 1, 2018: VISIR is not offered in P103. It will be modified and installed on UT4 for the NEAR experiment (New Earths in the Proxima centauri Region) during the first semester of 2019. It is foreseen that VISIR will be back for operation on UT3 in Period 104.
  • July 1, 2018: As announced in the Call for Proposals, during P102 VISIR will be moved to UT4 to serve in the Breakthrough Initiative.
  • April 26, 2017: The entrance window of VISIR was replaced by a new anti-reflection coated KRS5 window in order to remove the fringing pattern observed in HR spectroscopy since the intervention in June 2015. Preliminary measurements show an increase in sensitivity for several imaging filters and LR spectroscopy, while in the Q band the sensitivity appears to have reduced. More measurements under different atmospheric conditions are necessary to confirm these trends. The generally higher transmission of the new window made an adjustment of the detector readout times (and windowing) necessary.
  • September 01, 2016: Updated sensitivities for the P99 Call for Proposals. VISIR User Manual updated.
  • March 15, 2016: In addition to the currently offered modes (regular imaging, coronagraphy as well as LR, HR and HRX spectroscopy), also the burst mode and sparse aperture masking are offered for P98. More information can be found in the Call for Proposals and the VISIR User Manual.
  • December 21, 2015: The sensitivities in imaging and low resolution spectroscopy have been updated for phase 2 of P97. Due to strong demand, the M-band filter has been partially commissioned and will be available for P97. Because the filter has not yet been fully characterised, there is only limited support. The expected sensitivity is about 6 mJy/10σ/1h.
  • December 18, 2015: A new version of the VISIR data reduction pipeline is available for download at the VLT Instrument Pipelines web page.
  • November 16, 2015: The Call for Proposals for the VISIR Upgrade Science Verification has been issued. The deadline for the receipt of proposals is December 15, 2015. More details can be found on the VISIR Science Verification Webpage.
  • August 26, 2015: Operations with VISIR have been resumed after it has been verfied that the conversion factors are stable in an acceptable way (< 10% variation for the imager, < 18% for the spectrometer). An inspection of the instrument adressing the temperature instabilities is foreseen for mid-September.
  • August 14, 2015: Operations with VISIR have been suspended because the temperatures of the two detectors are unstable and this has an effect on the sensitivities and conversion factors. The problem is currently under investigation.
  • July 02, 2015: VISIR is back on the telescope after a successful intervention: on sky tests have shown the flexure problem has been solved. The spectrograph focussing mechanism is also working again. Further (re-)commissioning activities are planned for the next days.
  • May 23, 2015: VISIR has been taken off the telescope in order to correct an internal flexure of the instrument which prevented longer inegrations. The intervention will be carried out in June and allow for other minor improvements. The instrument is anticipated to be back on sky in early July and no significant impact on P95 science is expected.
  • March, 2015: Tests with the coronograph AGPM were carried out successfully, so that this observing mode can be offered for P96. The following rejection rates can be guaranteed, provided seeing conditions better than 0.9 arcsec: 3 in the 11_3_4QP, 4 in the 12_4_AGP and 3 in the NeII filters.
  • February 28, 2015: Start of phase 1 for P96 (Sep 2015 - Mar 2016) with dealine on March 26th, 2015; User Manual updated for P96 phase 1. NOTE: Additional information concerning the available instrument modes and sensitivities will be provided after March 15th when the ongoing commissioning run has been completed.
  • February 3, 2015: Start of Phase 2 proposal preparation for P95 (deadline: March 2nd, 2015).
  • February 2, 2015: User Manual updated for P95 phase 2.
  • January 13, 2015: Second VISIR re-commissioning run completed successfully.
  • August 26, 2014: VISIR is offered again in Period 95, pending successful recommissioning during Period 94. Only service mode is available, and a limited number of instrument modes: small-scale imaging (0.045 arcsec/px), long-slit low-res spectroscopy, and long-slit and cross-dispersion high-res spectroscopy (pixel scale for spectroscopy 0.076 arcsec/px). Burst mode, Sparse Aperture Masking, and medium-res spectroscopy are not available. The maximum chop throw is 10 arcsec. The instrument overheads remain the same. At this time the post-upgrade capabilities are not yet fully characterized, and the users should assume the same sensitivity as for the pre-upgrade VISIR. For details see the new Period 95 user manual. The astronomical community is encouraged to monitor the latest VISIR news on this page.
  • September 10, 2013: VISIR detectors are still out of specifications, as a consequence, VISIR is not offered during P93.
  • February 20, 2013: Due to problems with the new Raytheon detectors, VISIR will not be available for regular observations during P91 & P92.
  • October 25, 2012: Due to out-of-specifications properties of the new detectors, VISIR is not available for regular observations during P90. Most likely this will be the case for the entire period.
  • September 4, 2012: The P90 User manual applies also for P91 phase-I preparation.
  • August 17, 2012: An updated version of the P90 User Manual is available.
  • August 17, 2012: Problems during the first re-commissioning run did not allow to meet the sensitivity expectations. A second re-commissioning is planned for the end of October 2012. Regular science operations with VISIR are expected to resume at the begining of November 2012.
  • December 8, 2011: The VISIR upgrade is scheduled between May-September 2012. Thus, approved P89 programs will cluster either in the month of April or in the last 2 weeks of September 2012.
  • September 1, 2011: Release of P89 User Manual with first information on the new AQUARIUS detector.
  • September 1, 2011: VISIR upgrade is planned between January-March 2012.
  • June 23, 2011: Relative transmission curves for B and J filters made available.
  • March 28, 2011: Link to the forthcoming VISIR upgrade project
  • February 22, 2011: IMPORTANT: Given the forthcoming VISIRdetector upgrade, please note that VISIR P88 availability will be limited to the first part of the period. Further details will beprovided as soon as possible.
  • February 22, 2011: The J8.9 filter is confirmed to have a ghost, please avoid its use.
  • November 24, 2010: release of VISIR operating manual.
  • September 27, 2010: Emphasis (in the user manual) on the non availability of K-band science IMAGING.
  • June 28, 2010: Table.7 in the user manual is updated (i.e. the first line refering to HR-mode).
  • April 20, 2009: VISIR has been re-installed at the Cassegrain focus of UT3. Image quality was verified and the instrument is fully operational
  • January 31, 2006: first public release of the data reduction pipeline
  • December 20, 2005: user manual updated for P77 phase 2
  • December 20, 2005: guidecam tool a tool to select guide stars, adapted for VISIR
  • December 20, 2005: Cohen 81 a list of 81 standard stars, selected from Cohen et al. (see user manual )
  • December 20, 2005: Cohen 12 a list of 12 standard stars, selected from Cohen et al. (see user manual )
  • September 4, 2005: user manual updated for Call for Proposals P77
    • New low resolution, medium resolution and high-resolution, cross-dispersed modes released
    • Acquisition for spectroscopy can be done with the imager detector
    • Acquisition for imaging and spectroscopy can be done with a K-band filter