Paranal Telescopes and Instruments Overview

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

(valid for Period 81, April 1st, 2008 - Sept 30th, 2008).

Telescope Focus
  Nasmyth A Cassegrain Nasmyth B Interferometric



UT3 (Melipal) Visitor VISIR VIMOS




For details pls. refer to the Call for Proposal for Period 81

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 P81).

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
CRIRES Nodding cycle 0.4
CRIRES Change of wavelength setting 3.5
CRIRES Attached wavelength calibration 2.5
CRIRES Attached wavelength calibration and lamp flat 2
FORS2 Acquisition (1 cycle w/o exp. time)[1] 1.5 or 2
FORS2 Through Slit Image (2 cycles w/o exp. times)[2] 4
FORS2 Instrument Setup 1
FORS2 Read-out 100kHz binned (spectroscopy) 0.7
FORS2 Read-out 200kHz binned (imaging) 0.5
ISAAC[3] Instrument Setup, Imaging 0.5
ISAAC Instrument Setup, Spectroscopy (incl. slit check) 4-7
ISAAC Telescope Offsetting 0.25
ISAAC Target Acquisition 1-4
ISAACHw Read-out (per DIT, imaging) 0.07
ISAACAl Read-out (per DIT, imaging without chopping)[5] negligible
ISAACHw Read-out (per DIT, spectroscopy) 0.13
ISAACAl Read-out (per DIT, spectroscopy without chopping)[6] negligible
ISAACAl Imaging with chopping 40%[4]
ISAACAl Spectroscopy with chopping 30%[4]
ISAAC Night time flat[7] (one on-off pair) 4
ISAAC Night time arc[7] (one on-off pair) 3
ISAACAl Burst and FastJitter Modes See the Burst web page
FLAMES Acquisition[11] 9
FLAMES Instr. Setup UVES 1
FLAMES CCD read-out UVES 1
FLAMES Screen Flatfields 7
FLAMES Plate Configuration[12] 0-20
FORS1 Acquisition (1 cycle w/o exp. time)[1] 1.5 or 2
FORS1 Through Slit Image (2 cycles w/o exp. times)[2] 4
FORS1 Instrument Setup 1
FORS1 Retarder Plate Setup per PMOS/IPOL OB 1
FORS1 Read-out 100kHz binned (spectroscopy) 0.7
FORS1 Read-out 200kHz binned (imaging) 0.5
UVES Instrument Setup 1
UVES Acquisition. Bright Point Source 2
UVES Acquisition. Faint, Extended or Crowded Field 5
UVES Read-out[8], 1x1, Fast 0.75
UVES Read-out[8], 2x2, Slow 0.75
UVES Attached ThAr, Night time 1.5
UVES Attached Flat, Night time 2
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
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)[9] 5-8
VIMOS Attached arc (MOS)[10] 4
SINFONI Acquisition no AO 3
SINFONI Acquisition AO (NGS) 2 + 4*(DIT*NDIT)[13]
SINFONI Acquisition AO (LGS) 15 + 4*(DIT*NDIT)[13]
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
HAWK-I Target acquisition 3
HAWK-I Telescope offset 0.15
HAWK-I Read Out (per DIT) 0.03
HAWK-I Filter Change 0.35
NACO see User's Manual ---
MIDI One calibrated Visibility[14] 60
AMBER One calibrated Visibility (LR-HK mode)[14] 90+30*(number of bands)[15]
AMBER One calibrated Visibility (MR-K mode)[14] 90+30*(number of bands)[15]
AMBER One calibrated Visibility (HR-K mode)[14] 90+30*(number of bands)[15]

[1] 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.

[2] 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.

[3] ISAAC refers to both Aladdin and Hawaii, ISAACHw only to Hawaii detector, ISAACAl only to Aladdin detector.

[4] Global overheads in % are used for the LW imaging and spectroscopic chopping templates.

[5] For the Aladdin SW J+Block,H,K and LW low background NB_3.21 and NB_3.28 filters only.

[6] In Medium Resolution (MR) only.

[7] When required, see ISAAC P2PP page and the ISAAC user manual.

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

[9] Flat and arcs are mandatory for IFU.

[10] Arcs are mandatory for MOS blue settings and strongly recommended for the MOS red settings.

[11] 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.

[12] 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.

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

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

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