Overheads
Telescope/ Combined focus |
Instrument | Action | Time (seconds) |
|---|---|---|---|
| UT1 | Preset + GS acquisition + active optics |
360 | |
| UT1 | Preset + GS acquisition + active optics (2nd OB and following in a concatenation) |
(40+target separation in deg)+60 | |
| FORS2 | Acquisition IMG/IPOL/LSS (1 loop) |
90 |
|
| FORS2 | Acquisition MOS/MXU/PMOS (1 loop) | 120 | |
| FORS2 | Through Slit Image (2 loops w/o exp. times)[1] | 240 | |
| FORS2 | Instrument Setup | 30 |
|
| FORS2 |
Collimator exchange |
270 |
|
| FORS2 | Retarder Plate Setup per PMOS/IPOL OB | 60 | |
| FORS2 | E2V Read-out 100kHz binned (spectroscopy) | 39 | |
| FORS2 | E2V Read-out 200kHz binned (imaging) | 28 | |
| FORS2 |
E2V Read-out 200kHz unbinned (imaging) |
78 |
|
| FORS2 | MIT Read-out 100kHz binned (spectroscopy) | 41 | |
| FORS2 | MIT Read-out 200kHz binned (imaging) | 31 | |
| FORS2 | MIT Read-out 200kHz unbinned (imaging) | 62 | |
| KMOS | Acquisition, MOSAIC setup | 0 | |
| KMOS | Acquisition, non-MOSAIC setup, without exposure time, per cycle (2 cycles usually necessary): | ||
| KMOS | - : interaction + image reconstruction | 35 | |
| KMOS | Acquisition (2nd OB in a concatenation, MOSAIC and non-MOSAIC setups): arms parking and deployment | 240 | |
| KMOS | Read-out + writing image to disk | 6 | |
| KMOS | Image reconstruction | 20 | |
| KMOS | Offset (dither, i.e. within individual IFUs) | 9 | |
| KMOS | Offset to sky | 45 | |
| UT2 | Preset + GS acquisition + active optics |
360 | |
| UT2 | Preset + GS acquisition + active optics (2nd OB and following in a concatenation) |
(40+target separation in deg)+60 | |
| FLAMES | Acquisition[2] | 420 | |
| FLAMES | Instr. Setup GIRAFFE | 60 | |
| FLAMES | Instr. Setup UVES | 60 | |
| FLAMES | CCD read-out GIRAFFE | 60 | |
| FLAMES | CCD read-out UVES | 60 | |
| FLAMES | Screen Flatfields | 420 | |
| FLAMES | Plate Configuration[3] | 0-1200 | |
| VISIR | Target acquisition: normal and burst-mode imaging, blind | 120 | |
| VISIR | Target acquisition: normal and burst-mode imaging, and coronagraphy, 1 loop, incl. exposure | 420 | |
| VISIR | Target acquisition: SAM and coronagraphy, 1 loop, incl. exposure | 900 | |
| VISIR | Target acquisition: spectroscopy (>1 Jy source) | 900 | |
| VISIR | Target acquisition: spectroscopy (0.2 to 1 Jy source), incl. exposure | 1200 | |
| VISIR | Chopping and nodding duty cycle losses | 50% of exposure time | |
| UVES | Instrument Setup | 60 | |
| UVES | Acquisition. Bright Point Source | 120 | |
| UVES | Acquisition. Faint, Extended or Crowded Field | 300 | |
| UVES | Duty cycle Red arm[5], 1x1, Fast | 47 | |
| UVES | Duty cycle Red arm[5], 1x2, Fast (VM only) | 28 | |
| UVES | Duty cycle Red arm[5], 2x2, Slow | 52 |
|
| UVES | Duty cycle Red arm[5], 2x3, Slow (VM only) | 39 |
|
| UVES | Duty cycle Red arm[5], 1x1, Ultra-fast (VM only) |
19 |
|
| UVES | Duty cycle Blue arm[5], 1x1, Fast | 46 |
|
| UVES | Duty cycle Blue arm[5], 1x2, Fast (VM only) | 32 |
|
| UVES | Duty cycle Blue arm[5], 2x2, Slow | 48 | |
| UVES | Duty cycle Blue arm[5], 2x3, Slow (VM only) | 37 | |
| UVES | Duty cycle Blue arm[5], 1x1, Ultra-fast (VM only) |
22 |
|
| UVES | Attached ThAr, Night time; set-up dependent, see User Manual Table 4.2 |
41 to 89 | |
| UVES | Attached Flat, Night time; set-up dependent, see User Manual Table 4.2 |
44 to 190 | |
| UT3 | Preset + GS acquisition + active optics |
360 | |
| UT3 | Preset + GS acquisition + active optics (2nd OB and following in a concatenation) |
(40+target separation in deg)+60 | |
| SPHERE | Acquisition with GoTo template (2nd OB and following in a concatenation) |
180 |
|
| SPHERE | Acquisition with Hopback template (2nd OB and following in a concatenation) |
60 |
|
| SPHERE | Acquisition without coronagraph centering |
600 |
|
| SPHERE | Acquisition with coronagraph centering |
900 |
|
| SPHERE | Flux measurement (incl. exposure) |
210 | |
| SPHERE | Centering measurement (incl. exposure) |
210 | |
| SPHERE | IFS observations, per exposure |
NDIT*1.7+10 |
|
| SPHERE | IFS observations, per dithering position |
4 |
|
| SPHERE | IRDIS observations, per exposure |
NDIT*0.85+10 |
|
| SPHERE | IRDIS observations, per dithering position |
4 |
|
| SPHERE | IRDIS_LSS observations, attached wavelength calibration |
210 | |
| SPHERE | ZIMPOL observations, per exposure, StandardImaging readout mode |
NDIT*0.1+3 |
|
| SPHERE | ZIMPO observations, per exposure, FastPolarimetry readout mode |
NDIT*0.1+3 |
|
| SPHERE | ZIMPOL observations, per exposure, SlowPolarimetry readout mode | NDIT*0.1+13 | |
| SPHERE | ZIMPOL observations, per polarimetric cycle | 2*5 | |
| SPHERE | ZIMPOL observations, per dithering position | 5 | |
| SPHERE | ZIMPOL observations, per number of field angle values | 5 | |
| XSHOOTER | Target acquisition (3 loops, incl. telescope offset and AG readout time; excl. AG integration time): direct/blind | 49/65 | |
| XSHOOTER | Telescope offsetting | 15 | |
| XSHOOTER | Instrument setup Slit | 30 | |
| XSHOOTER | Instrument setup IFU | 60 | |
| XSHOOTER | Delay before start of exposure: UVB | 0 |
|
| XSHOOTER | Delay before start of exposure: VIS | 5 |
|
| XSHOOTER | Delay before start of exposure: NIR | 10 |
|
| XSHOOTER | UVB Read-out[4], 1x1, Slow/Fast | 68/16 |
|
| XSHOOTER | UVB Read-out[4], 1x2, Slow/Fast | 34/8 |
|
| XSHOOTER | UVB Read-out[4], 2x2, Slow/Fast | 17/4 |
|
| XSHOOTER | VIS Read-out[4], 1x1, Slow/Fast | 89/21 |
|
| XSHOOTER | VIS Read-out[4], 1x2, Slow/Fast | 45/11 |
|
| XSHOOTER | VIS Read-out[4], 2x2, Slow/Fast | 22/5 |
|
| XSHOOTER | NIR Read-out (per DIT) | 1.46 |
|
| XSHOOTER | AG camera detector Read-out | 1 |
|
| CRIRES | Acquisition with AO |
300 |
|
| CRIRES | Acquisition without AO |
180 |
|
| CRIRES | Read-out |
2.4 + 1.43 x (NDIT-1) |
|
| CRIRES | Nodding cycle (AB or BA) |
24 |
|
| CRIRES | Change of wavelength setting |
80 |
|
| CRIRES | Metrology in YJ[9] |
110 |
|
| CRIRES | Metrology in HK[9] |
180 |
|
| CRIRES | Attached wavelength calibration |
150 |
|
| CRIRES | Attached lamp flat |
120 |
|
| CRIRES | Change of position angle |
60 |
|
| UT4 | Preset + GS acquisition + active optics |
360 | |
| UT4 | Preset + GS acquisition + active optics (2nd OB and following in a concatenation) |
(40+target separation in deg)+60 | |
| HAWK-I | Blind acquisition in No AO mode and Instrument Setup | 60 | |
| HAWK-I | Acquisition (Move to Pixel) in No AO mode and Instrument Setup | 180 | |
| HAWK-I | Blind acquisition with GRAAL and Instrument Setup | 180 | |
| HAWK-I | Acquisition (Move to Pixel) with GRAAL and Instrument Setup | 300 | |
| HAWK-I | Telescope offset (large) | 45 | |
| HAWK-I | Telescope offset (small) | 9 | |
| HAWK-I | Read Out (per DIT), normal observation |
1.8 | |
| HAWK-I | Read Out (per DIT), FastPhot/Burst | NXxNYx1.e-06 | |
| HAWK-I | Filter Change | 21 | |
| HAWK-I | Header merging | 5 |
|
| HAWK-I | After exposure overhead | 8 | |
| MUSE | Acquisition: Slow Guiding System loop closure | 20 | |
| MUSE | Closure of AO loops (all AO modes) | 180 | |
| MUSE | Detector setup | 15 | |
| MUSE | Detector readout + file merging | 60 | |
| MUSE | Intra-exposure detector delay (for multiple exposures) | 5 | |
| MUSE | Small telescope offset < 2 arcmin | 15 | |
| MUSE | Large telescope offset > 2 arcmin | 45 | |
| MUSE | Slow Guiding System closure after offset | 10 | |
| MUSE | Derotator offset - WFM | 5 + 0.11/deg | |
| MUSE | Derotator offset - NFM | 5 + 1.1/deg | |
| MUSE | Attached calibration - WFM | 20 + 106/flatfield exposure + 112/arc lamp exposure |
|
| MUSE | Attached calibrations - NFM | 20 + 162/flat field exposure + 148/arc lamp exposure (at least 1 per lamp - 3 lamps ) | |
| MUSE | Return to origin (no offset/small offset/large offset) | 0/15/45 | |
| ICCF | Preset any UT + GS acquisition + active optics |
360 | |
| ICCF | Preset any UT + GS acquisition + active optics (2nd OB and following in a concatenation) |
(40 + target separation in deg) + 60 | |
| ICCF |
Additional overheads in 4-UT mode | 120 | |
| ESPRESSO | Target acquisition in 1-UT mode | 45 | |
| ESPRESSO | Target acquisition in 4-UT mode |
300 | |
| ESPRESSO | Instrument setup | 30 | |
| ESPRESSO | Readout, transfer, wiping; HR11, 1x1_FAST | 45 |
|
| ESPRESSO | Readout, transfer, wiping; HR21, 2x1_SLOW | 68 |
|
| ESPRESSO | Readout, transfer, wiping; HR84, 8x4_SLOW | 36 |
|
| ESPRESSO | Readout, transfer, wiping; UHR11, 1x1_FAST | 45 |
|
| ESPRESSO | Readout, transfer, wiping; MR42, 4x2_SLOW | 41 |
|
| ESPRESSO | Readout, transfer, wiping; MR84, 8x4_SLOW | 36 |
|
| VLTI | |||
| GRAVITY | One calibrated visibility, CAL-SCI [6] | 3600 | |
| GRAVITY | One calibrated visibility, CAL-SCI-CAL[6] | 5400 (requires waiver) | |
| GRAVITY | Swapping template in dual-field observation | 300 | |
| MATISSE | LM-band low and med resolution, no N-band phot CAL-SCI [6] | 2400 | |
| MATISSE | LM-band low and med resolution, no N-band phot CAL-SCI-CAL [6] | 3600 | |
| MATISSE | LM-band low and med resolution, with N-band phot CAL-SCI [6] | 3600 | |
| MATISSE | LM-band low and med resolution, with N-band phot CAL-SCI-CAL [6] | 5400 | |
| MATISSE | L-band high and high+ resolution, no N-band phot CAL-SCI [6] | 3000 | |
| MATISSE | L-band high and high+ resolution, no N-band phot CAL-SCI-CAL [6] | 4500 | |
| MATISSE | L-band high and high+ resolution, with N-band phot CAL-SCI [6] | 4200 | |
| MATISSE | L-band high and high+ resolution, with N-band phot CAL-SCI-CAL [6] | 6300 | |
| PIONIER | Hmag -1.0 to 6.0 One calibrated Visibility CAL-SCI-CAL [6] | 1800 | |
| PIONIER | Hmag -1.0 to 6.0 One calibrated Visibility CAL-SCI-CAL-SCI-CAL [6] | 2700 |
|
| PIONIER | Hmag 6.1 to 7.5 One calibrated Visibility CAL-SCI-CAL [6] | 2400 | |
| PIONIER | Hmag 6.1 to 7.5 One calibrated Visibility CAL-SCI-CAL-SCI-CAL [6] | 3600 | |
| PIONIER | Hmag 7.6 to 9.0 One calibrated Visibility CAL-SCI-CAL [6] | 2700 | |
| PIONIER | Hmag 7.6 to 9.0 One calibrated Visibility CAL-SCI-CAL-SCI-CAL [6] | 4500 | |
| VISTA | Preset | 120 | |
| VISTA | Preset (2nd OB and following in concatenation) | 20+ target separation in deg | |
| VIRCAM | Guide star handling | 3 | |
| VIRCAM | Autoguiding start | 5 | |
| VIRCAM | Active Optics start | 45 | |
| VIRCAM | Filter change | 21-40 | |
| VIRCAM | Detector readout | 2 per DIT | |
| VIRCAM | Writing FITS to disk | 4 | |
| VIRCAM | Pawprint change | 15 | |
| VIRCAM | Jitter offset | 8 | |
| VIRCAM | Micro step | 4 | |
| VST | Preset | 120 | |
| VST | Offset at template start | 15 | |
| VST | Set rotator position angle (PA) (abs(PA) < 180) | PA/2 | |
| VST | 2nd OB and following in concatenation | ||
| VST | - Preset | 30+(target separation in deg)/1.5 | |
| VST | - Set Rotator PA | (abs(PA_n)+abs(PA_n+1))/2 [7] | |
| OmegaCAM | Guide Star (GS) aquisition | 60 | |
| OmegaCAM | Acquisition of new Guide Star after offset | 60 | |
| OmegaCAM | Re-acquisition of same Guide Star after offset [8] | 5 | |
| OmegaCAM | Pick object for Move to Gap acquisition | 45 | |
| OmegaCAM | Filter exchange between acquisition and 1st science templates: | ||
| OmegaCAM | - different magazine | 65 | |
| OmegaCAM | - same magazine | 115 | |
| OmegaCAM | Filter exchange between science templates: | ||
| OmegaCAM | - different magazine | 35 | |
| OmegaCAM | - same magazine | 85 | |
| OmegaCAM | Detector readout and data writing to disk, last exposure of an OB | 0 | |
| OmegaCAM | Detector readout and data writing to disk, other exposures | 40 | |
| OmegaCAM | Start Active Optics/Image Analysis | 180 |
Direct links to instruments on UT1, UT2, UT3, UT4, ICCF, VLTI, VISTA, VST.
[1] 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.
[2] Includes configuration of UVES fibres, homing the rotator to zero degrees, swapping of the plates, and the acquisition of field. 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.
[3] 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.
[4] Detectors are read sequentially.
[5] Duty cycle includes readout, writing image to disk, and detector wiping. In a dichroic exposure the CCDs are read out in parallel: only the longest duty cycle must be taken into account.
[6] This time includes all telescope and instrument overheads as well as the integration times on the science target and the calibrator. In p1, set the time from this table in the total "Telescope Time" field (in the blue box), and leave the details of the observations unused; cf. this example in p1demo.
[7] 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.
[8] 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.
[9] In science templates only. Metrology is done in parallel to the telescope preset during acquisition and does not require additional overhead to the acquisition templates.