README web version of /home/usg/OPS/MTS/readme_xml/readme_77503800

Principal Investigator Email Address

• boehnhardt@mps.mpg.de

Estimated Total Execution Time (hours, including overheads)

• 02h32m

General Description

• Science
  =======
  R filter imaging of the ROSETTA target comet 67P/Churyumov-Gerasimenko in parallel
   with Spitzer. 
  
  The main goal of this combined observations is to measure the reflected light (VLT)
   and the thermal emission (Spitzer) of the nucleus in order to determine its size
   and surface albedo. For this reason, it is important that the FORS2 imaging of the
   comet is performed as much as possible simultaneously with the Spitzer observations
   that happen on 
  
  16 Aug 02:15UT, 
  23 Aug 02:15UT, 
  31 Aug 01:30UT.
  
  In order to determine the rotation phase of the nucleus at the time of Spitzer observations,
   it is required that VLT observes the comet twice around the time of the Spitzer
   observations, i.e. ideally once simultaneously with Spitzer and another time AT
   LEAST about 3h and NOT MORE THAN 3 days before or after Spitzer. 
  
  Otherwise, this is a simple point-and-shoot program on a MOVING target! Note the
   offsetting amplitudes (change of guidestar is possible, also guide probe vignetting
   of the lower CCD).
  
  
  IMPORTANT NOTES
  ===============
  
  - If possible, one OB to be performed simultaneously with Spitzer (on 16 Aug 02:15UT,
   23 Aug 02:15UT and 31 Aug 01:30UT). If this is not possible, try to execute one
   OB as close in time to the Spitzer observing epoch as possible.
  
  - 2 OBs (extension _A and _B) to be observed per Spitzer observing epoch: minimum
   time difference between OBs must be more than about 3h (earlier or later) and less
   than 3 days (earlier or later)!
  
  - Blind acquisition, i.e. object identification is not necessary, though easily
   possible (by blinking). Please check telescope pointing through DSS image!
  
  - The OB names contain the reference epoch of the Spitzer observations.
  
  - Ephemeris provides in 10min time steps for the daily visiblity window of the comet
   at Paranal
  * RADEC positions (hh mm ss.ss, sdd mm ss.s)
  * RADEC velocities (arcsec/s)
  * Airmass
  * Vis. Brightness (mag)
  * distance comet-moon TOM (deg)
  * moon phase (%)
  
  
  Cook instructions for OB execution:
  ===================================
  - perform at least one OB per epoch (as mentioned in the OB name) in parallel to
   Spitzer observations
  - second OB per epoch to be performed at least about 3h and no more than 3 days
   apart the first one (before or after)
  - select OB for execution
  - check requirement for environmental conditions (CLR, moon phase/distance)
  - in OB enter RA and DEC from target ephemeris (fields RA and DEC) that are closest
   in time to the expected start time of the OB
  - in OB enter differential velocity in RA and DEC (fields VEL_RA and VEL_DEC) from
   target ephemeris that are closest in time to the expected start time of the OB
  - perform preset and start R filter offset exposures

Waiver Requests

• no applicable

Critical Observing Condition Constraints

• CLR conditions are required!

Time-Critical Aspects

• In total 6 OBs are provided: 2 each for 3 Spitzer observing epochs (on
   16 Aug 02:15UT, 23 Aug 02:15UT  and 31 Aug 01:30UT).
  
  One FORS OB at each Spitzer epoch should be executed in parallel (within about 0.5h)
   to the Spitzer obs., i.e. one on 16 Aug 02:15UT, one on 23 Aug 02:15UT, one on 31
   Aug 01:30UT. 
  
  The second FORS OB for the respective Spitzer observing epoch should be executed
   in the minimum 3h before/after and at most 3 days before/after the first one.

Special Execution Requirements

• See time-critical aspects!

Special Calibration Information

• According to FORS calibration plan

ToO Information

• Not a ToO program.

ToO Activators List

• Not applicable.

Is this a Pre-imaging run ?

• false

Pre-imaging Requirements

• Not aplicable.

Source(s) of Pre-imaging

• ---(Empty)---

Pre-imaging sources not listed above

• ---(Empty)---

Do all your OBs comply with the instrument-specific requirements listed
 on the instrument-specific Phase 2 web page ?

• YES

If this is a pre-imaging run, did you select PRE-IMAGING for the Observing
 Category for each Observing Template ?

• N/A

Do all your finding charts comply with both the general and instrument-specific
 Phase 2 Web Pages ?

• N/A

If you submitted OBs for standard stars, did you specify the magnitude
 and spectral type of all standard stars in the OBs ?

• N/A

Have you included OBs for any calibrations that you need but which are
 not part of the Calibration Plan ?

• N/A

If you are observing Moving Targets, have you attached suitable ephemeris
 files to your OBs?

• YES

If you have preferences which OBs should be executed first, did you make
 use of the User Priority field in the OBs ?

• N/A

If this is a run that requires coordinated observations with other facilities,
 did you give proper instructions in the Time-Critical Aspects Section ?

• YES

If you have prepared your finding charts with tools other than FIMS,
 do they comply with the specifications on the FORS2 Phase 2 web page ?

• N/A