Paranal Instrumentation - Period 91

The following table identifies the offered Paranal telescopes and instruments and their location for P87. The links to the different instruments provide an overview of the respective instrument capabilites and the offered instrument modes

(valid for Period 90, October1st, 2012 - March 31st, 2013).

Telescope Focus
  Nasmyth A Cassegrain Nasmyth B Interferometric



VLTI Visitor Instrument




VLTI Visitor Instrument


For details please refer to the Call for Proposals for Period 91.
Information on Paranal decommissioned instruments is available on a separate page.

Telescope and Instrument Overheads

Service and Visitor Mode observers must include in their proposals the overhead times associated with their science target observations. In service mode, time for night-time calibrations and associated overheads should only be included in cases where the accuracy of the calibration plan is not deemed sufficient for the science goals. The following tables provides typical times to estimate the overheads associated with their observations.More details can be found in the instrument manuals.

(valid for P91).

Telescope/Instrument Action Time (minutes)
Unit Telescope Preset 6
CRIRES Acquisition without AO 3
CRIRES Acquisition with AO 5
CRIRES Read-out 10%-60% of exp. time[1]
CRIRES Nodding cycle 0.4
CRIRES Change of wavelength setting 1.5 - 2.5 [1]
CRIRES Change of derotator position angle 1
CRIRES Attached wavelength calibration 2.5
CRIRES Attached lamp flat 2
FORS2 Acquisition (1 cycle w/o exp. time)[2] 1.5 or 2
FORS2 Through Slit Image (2 cycles w/o exp. times)[3] 4
FORS2 Instrument Setup 1
FORS2 Retarder Plate Setup per PMOS/IPOL OB 1
FORS2 Read-out 100kHz binned (spectroscopy) 0.7
FORS2 Read-out 200kHz binned (imaging) 0.5
FLAMES Acquisition[4] 9
FLAMES Instr. Setup UVES 1
FLAMES CCD read-out UVES 1
FLAMES Screen Flatfields 7
FLAMES Plate Configuration[5] 0-20
UVES Instrument Setup 1
UVES Acquisition. Bright Point Source 2
UVES Acquisition. Faint, Extended or Crowded Field 5
UVES Read-out[6], 1x1, Fast 0.75
UVES Read-out[6], 2x2, Slow 0.75
UVES Attached ThAr, Night time 1.5
UVES Attached Flat, Night time 2
XSHOOTER Target acquisition 3-5
XSHOOTER Telescope offsetting 0.25
XSHOOTER Instrument setup Slit 0.5
XSHOOTER Instrument setup IFU 1
XSHOOTER UVB Read-out[7], 1x1, Slow/Fast 70/19 sec
XSHOOTER UVB Read-out[7], 1x2, Slow/Fast 38/12 sec
XSHOOTER UVB Read-out[7], 2x2, Slow/Fast 22/8 sec
XSHOOTER VIS Read-out[7], 1x1, Slow/Fast 92/14 sec
XSHOOTER VIS Read-out[7], 1x1, Slow/Fast 48/14 sec
XSHOOTER VIS Read-out[7], 1x1, Slow/Fast 27/9 sec
XSHOOTER NIR Read-out (per DIT) 0.88 sec
VIMOS IMG acquisition + Instrument setup 3
VIMOS MOS acquisition + Instrument setup 15
VIMOS IFU acquisition + Instrument setup 10
VIMOS Read-out IMG,MOS,IFU (4 quadrants) 1
VIMOS Change of Filter (IMG) 3
VIMOS Attached screen flat+arc (IFU, MOS)[8] 5-8
VISIR Imaging target acquisition (incl. instrument setup):  
VISIR fine acquisition (>1 Jy source) 5
VISIR blind preset (<1 Jy source) 2
VISIR Imaging read-out/chopping 50% of int.time
VISIR Burst read-out/nod-chopping 80% of int.time
VISIR Spectroscopy target acquisition (incl. instrument setup):  
VISIR >1 Jy source 15
VISIR 0.2 - 1 Jy source 30
VISIR Spectroscopy read-out/chopping 50% of int.time
HAWK-I Acquisition and Instrument Setup 1
HAWK-I Acquisition (Move to Pixel) and Instrument Setup 3
HAWK-I Telescope offset (large) 0.75
HAWK-I Telescope offset (small) 0.15
HAWK-I Read Out (per DIT) 0.03
HAWK-I Filter Change 0.35
NACO see User's Manual ---
SINFONI Acquisition no AO 3
SINFONI Acquisition AO (NGS) 2 + 4*(DIT*NDIT)[9]
SINFONI Acquisition AO (LGS) 9 + 4*(DIT*NDIT)[9]
SINFONI Acquisition target (AO and no AO) 4 + 4*(DIT*NDIT)
SINFONI Instrument setup (per grating change) 2.5
SINFONI Science exposure read-out (per DIT) 0.07
SINFONI Detector setup (per DIT x NDIT) 0.3
AMBER One calibrated Visibility CAL-SCI-CAL  
AMBER LR [10] 15+45*(number of bands)[11]
AMBER MR, HR [10] 30+45*(number of bands)[11]
AMBER One calibrated Visibility SCI-CAL  
AMBER LR [10] 10+30*(number of bands)[11]
AMBER MR, HR [10] 20+30*(number of bands)[11]
MIDI One calibrated Visibility SCI-CAL [10] 50
MIDI One calibrated Visibility CAL-SCI-CAL [10] 75
VISTA Preset 2
VISTA Preset (2nd OB and following in concatenation) 0.33+ (target separation in deg)/60
VIRCAM Guide star handling 0.05
VIRCAM Autoguiding start 0.083
VIRCAM Active Optics start 0.75
VIRCAM Filter change 0.35-0.67
VIRCAM Detector readout 0.03 per DIT
VIRCAM Writing FITS to disk 0.067
VIRCAM Pawpring change 0.17
VIRCAM Jitter offset 0.067
VIRCAM Micro step 0.067
VST Preset 2
VST Offset at template start 0.25
VST Set rotator position angle (PA) (abs(PA) < 180) PA/120
VST 2nd OB and following in concatenation  
VST - Preset 0.5+(target separation in deg)/90
VST - Set Rotator PA (abs(PA_n)+abs(PA_n+1))/120 [13]
OmegaCAM Guide Star (GS) aquisition 1
OmegaCAM Acquisition of new Guide Star after offset 1
OmegaCAM Re-acquisition of same Guide Star after offset [14] 0.08
OmegaCAM Pick object 0.75
OmegaCAM Filter exchange :  
OmegaCAM - different magazine 1.08
OmegaCAM - same magazine 1.92
OmegaCAM Detector readout and data writing to disk 0.67
OmegaCAM Start Active Optics/Image Analysis 3

[1] See CRIRES User's manual for more details

[2] Typically one cycle for the target acquisition (exposure time of the acquisition image not included). MXU, MOS, and PMOS: 2 min. LSS,IPOL,ECH: 1.5 min (per cycle). IMG none.

[3] Through-slit exposures are mandatory for all spectroscopic OBs. Two cycles are typically enough to center the target on the slit (exposure time of the through slit image not included). MXU,MOS,PMOS,LSS,ECH 2.0 min (per cycle), IMG and IPOL none.

[4] Includes configuration of UVES fibres, homing the rotator to zero degrees, swapping of the plates, and the acquisition of field; telescope preset, acquisition of the guide star, and start of the active optics are not included and account with additional 6 minutes. For ARGUS fast acquisition (VM only), the acquisition overhead is 2 minutes and is calculated assuming that plate 2 is already attached to the telescope.

[5] Plate configuration takes 20 minutes at most (Medusa fibres). This does not translate into additional overheads if the running exposure on the other plate is at least 20 minutes long. Plate configuration overheads have to be added if the exposure time is shorter than 20 minutes.

[6] In a dichroic exposure the CCDs are read out in parallel.

[7] Detectors are read sequentially.

[8] Flat and arcs are mandatory for IFU.

[9] Here: DIT and NDIT as required for the AO natural guide star (NGS).

[10] This time includes all telescope and instrument overheads as well as the integration times on the science target and the calibrator.

[11] With a maximum number of 3 bands per wavelength setting. For each new wavelength setting, a new calibrated visibility has to be obtained.

[12] When switching from OBn to OBn+1 in a concatenation, the overhead for repositioning the rotator is (abs(PA(OBn)) + abs(PA(OBn+1)))/(2 deg/s). I.e. for an OB sequence with PA=90 degrees, the overhead per OB is 90s. PAs > 180 or < -180 are interpreted as modulu 360. E.g. PA=270 implies motion to PA=-90.

[13] The default dither sequence 'diagonal' with N=5 exposures will not require to change the guide star. A larger offset sequence increases the overhead due to the reaquisition of a new guide star. For exposures shorter than 1-2 minutes, observations can be performed without guiding.