README web version of /home/usg/OPS/MTS/readme_xml/readme_80507700

Principal Investigator Email Address

• csnodgra@eso.org

Estimated Total Execution Time (hours, including overheads)

• 4 hours

General Description

• We want to take deep images of a faint comet at aphelion to search for
   activity, and to measure the nucleus properties if we find no activity. There are
   3 long OBs (waiver requested to have OBs of 1.3 hours duration), one for each of
   VRI. Total time 4 hours.
  
  Other than the fact that the target is moving and the exposure times need to be
   adjusted based on the ephemeris file (see execution requirements section below)
   this is simple VRI imaging. Standard calibrations please.
  
  Note that the ephemeris file has positions, exposure times, total number of exposures,
   and an estimate of the expected nucleus magnitude assuming that the comet is inactive.
   It has one line every 10 minutes whenever the comet is above the airmass cut off
   and the moon is down, but it doesn't move so fast that the position needs to be
   updated every 10 minutes. One position at about the midtime of the OB execution
   will keep the comet in the FOV.

Waiver Requests

• Waiver ID 280.C-5077A.01 submitted to have OBs longer than 1 hour in duration.
   Decision pending, but OBs & this readme submitted now anyway to have a chance
   of getting the OBs into the queue before this weekend (ie during the dark time in
   April). NB the total time on the OBs currently is under 1 hour to allow the p2pp
   submission process to work, but each will take 1.3 hours using the exposure times
   and number of exposures listed in the ephemeris file.

Critical Observing Condition Constraints

• Dark time required as target is faint. reasonable seeing needed to look
   for faint activity. NB if seeing is considerably better than 0.5", exposure times
   will need to be reduced proportionally to the seeing (and the total number of integrations
   increased).

Time-Critical Aspects

• ASAP please!
  
  It would be best to do all 3 OBs together, if possible, although obviously that
   may be tricky from an operations point of view, and should be seen as a weak constraint.
   The OBs should be executed as early in P81 as possible, both from the visibility
   of the target and to get the comet as close to aphelion as possible.

Special Execution Requirements

• Although this is a moving target, we want to track at the sidereal rate
   - do NOT add an additional velocity! This is so we can use the stars to measure
   the image PSF and compare the comet PSF to look for faint activity. To do this we
   have to keep the exposures short, and these depend on the rate of motion (exposure
   times = time for the target to move 0.5"). The ephemeris file lists the position
   at each possible time in P81 along with the exposure time and the number of exposures
   that will give a total OB of 1.3 hours at that epoch. PLEASE UPDATE THE EXPOSURE
   TIME AND NUMBER OF TELESCOPE OFFSETS as well as the RA & DEC position to the
   values listed in the ephemeris file at execution time. Note that the OB is set up
   to continue looping around 4 jitter positions for the total number of exposures
   (= number of offset positions), so there is no need to update the list of offset
   positions - p2pp will automatically repeat from the start of the list.
  
  Please also check the first few images to make sure that the comet is not too close
   to any bright stars.

Special Calibration Information

• ---(Empty)---

ToO Information

• ---(Empty)---

ToO Activators List

• ---(Empty)---

Is this a Pre-imaging run ?

• false

Pre-imaging Requirements

• ---(Empty)---

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 ?

• YES

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

• N/A

If you have prepared your finding charts with tools other than FIMS,
 do they comply with the specifications on the FORS1 Phase 2 web page ?

• N/A