Logbook of MUSE changes

This page documents the changes to the instrument since it started operations. Some of these changes have an impact on the posterior data reduction and the associated calibrations. We attempt to give a guideline about which calibration products are affected by each of the changes. To understand what is writen in the table you might need to know the meaning of a few terms:

BB: Basic Board (one of the NGC cards)

DCS: Detector Control System. System that control the detector elctronics. We use it here in a more generic way to refer to the detectors harware and software.

FEB: Front End Board

ICS: Instrument Control System. The system that controls the instrument itself, such as mode selection, filter insertions, etc.

NGC: New Generation Controller

PPRS: Paranal Problem Reporting System, the ticketing ystem used to keep track of problems at the Paranal observatory

MB: Mother Board

SN: Stock Number


When Subsystem What Comment
01 May 2017 DCS

Readout noise reduction in some channels due to the following actions:

  • 2017-05-01: CHAN09 pre-amp board was replaced
  • 2017-05-02: CHAN02, 06, 09, 10, 11, 15, and 17 clock, bias, and video cable bundles from cryostats to controller were separated and re-routed significantly reducing the RON in several of those channels.
Note that this affects bias and darks so new science taken after May 2nd should be reduced with newly taken biases and darks.
26 April 2017 ICS

An intervention to move the adapter/rotator system where GALACSI is mounted was succesfully carried out. MUSE was not touched but the intervention had the following effects:

  • the axis of ADA/ROT, which was misaligned with respect to the MUSE center of rotation after an intervention to replace motor segments prior to GALACSI installation, was brought back to proper alignment.
  • A small vignetting from the GALACSI annular mirror in one corner of the MUSE field of view, for some relative rotator positions, was eliminated.
The quality of the tracking near zenith has improved. We recommend to use new sky flats taken post intervention for the post inetrvention science data.
22 April 2017 ICS

Channel realignment as follow:

  • 2017-04-19: channels 02, 03, 07, 09, 21 aligned
  • 2017-04-21: channels 10
  • 2017-04-22: channel 3, 18
  • 2017-05-02: intervened channels were glued
The channel realignment is done to correct for the drift in relative illumination between the top and bottom slices of a single channel. Data taken after the realignment should be reduced using newly taken lamp flats, skyflats, and illumination frames.
06 March 2017 All GALACSI has been installed in the optical PATH to MUSE.
The SGS patrol feld has been reduced in size. The calibration files have not changed much after the installation, but we nevertheless recommend that data taken after 6 March be reduced with calibration files taken after that date.
09 December 2016
DCS Back to proper detector configuration files. All calibrations are affected.
25 Nov 2016 DCS Improper detector configuration file installed until 8 December 2016. All calibrations are affected. Only science target affected is the one observed for the MUSE recommissioing.
09 Oct 2016 All MUSE out due to installation of adaptive secondary mirror  
21 June 2016 ICS Realignment of channels 01, 06, 09, 12, 13, and 19. All calibrations are affected excet bias and darks.
27 Nov 2015 All At 2015-11-27T21:06:57 UT a medium size earthquake affected Paranal. The instrument was checked fine after the eartquake. Nevertheless, we recommend to use post-eartquake calibrations for post-eartquake data. Bias, darks, flats, arcs, geometries, astrometries, etc.
26 Nov 2015
DCS Changed pre-amp cables (better grounded) for channels CHAN01, 03, 04, 09, 20. Reduced RON and better stability is expected in those channels. This should affect all frames taken in those channels.
19 July 2015 DCS CHAN01 and CHAN09: The detector voltage configuration files for were changed. The first file with the new voltages is MUSE.2015-07-19T19:09:04.193.fits. This change affects BIAS, DARKS, FLATS, ARCS, and GEOMETRIES. Science taken after 2015-07-19 must be reduced with the calibration data taken after this date. Bias, Darks, Flats, Arcs, Geometry
7 May 2015 DCS Change of amplifiers and cables in multiple channels. Clocking mode of detectors. New DCS software. Bias, Darks, Screen flats, Arcs, Geometry, Twilight flats, Astrometry
31 Mar 2015 DCS Detector Vessel 1 (CHAN01) has been exchanged. New detector does not show evidence of amplifier glow. Bias, Darks, Screen flats, Arcs, Geometry, Twilight flats, Astrometry
19 Feb 2015 DCS CHAN09: PPRS-060043 BB SN#115 was replaced by BB SN#92 and bias level adjusted to 1200 Bias, darks
1 Dec 2014 DCS CHAN16 warmed up to exchange vacuum gauge Bias, darks
29 Nov 2014 ICS Realignment of CHAN 02, 03, 07 and 08. See PPRS-59180 Flats, Waves, LSFs
11 Nov 2014 DCS CHAN13: FEB#80 removed and FEB#113 installed Bias, darks
1 Nov 2014 DCS


  • FEB board #80 removed from NGC3 channel13
  • FEB board #113 installed.
Bias, darks, flats, linearity
9 Oct 2014 DCS


  • Removed PreAmp MB Rev 3.1 #43, AddOn Rev 2.0 #27
  • Installed PreAmp MB Rev 3.1 #85, AddOn #69
Bias, darks, flats, linearity
9 Oct 2014 DCS


  • Removed PreAmp MB Rev 3.1 #50, AddOn Rev 2.0 #34
  • Installed PreAmp MB Rev 3.1 #83, AddOn #67
Bias, darks, flats, linearity
9 Oct 2014 DCS


  • Removed PreAmp MB Rev 3.1 #29, AddOn Rev 2.0 #11 (<=== Not sure if AddOn is #11 to #17 as the label is partially gone, pls check on Twiki)
  • Installed PreAmp MB Rev 3.1 #50, AddOn #34
Bias, darks, flats, linearity
11 Sep 2014 DCS NGC#3 switched off and FEB boards removed and reseated Bias, Darks. This NGC controls CHANs: 01, 07, 09, 13, 19, and 21.
26 Jul 2014 DCS CH09: Basic Board reseated (RON unstable) Bias, Darks
25 Jul - 3 Aug 2014   Commissioing 2b  
20-29 June   Science Verification observations  
30 April 2014 ICS CHAN02, CHAN20 and CHAN22 Light tightness improved by: Aluminium tape used to cover focus screws Darks, Flats
27 Apr - 6 May 2014   Commissioning 2A  
7-22 Feb 2014   Commissioning 1  
30 Jan - 4 Feb 2014   MUSE Alignment  
31 Jan 2014   FIRS LIGHT  
10 Sep 2013   Preliminary acceptance Europe