README web version of /home/usg/OPS/MTS/readme_xml/readme_81502900

Principal Investigator Email Address

• D.M.Russell@uva.nl

Estimated Total Execution Time (hours, including overheads)

• 02:59:50.00

General Description

• This is a DDT to measure the linear polarisation in 4 filters of a single
   target - a black hole X-ray binary. The source is variable. We wish to perform this
   study at 6 dates to sample variations with time and flux. For 2 of the epochs we
   will also observe a polarimetric standard star.

Waiver Requests

• WaiverID:  281.D-5029A.01
  This Waiver was sent on 2008-07-21 and was approved on 2008-07-22.
  
  Two requests:
  1) The use of 4 broadband filters in each OB (it is our science goal to measure
   the linear polarisation of the target in 4 filters, not 3)
  
  2) We have unfortunately found that a few 'bright' stars (brightest is J = 9.7,
   H = 8.7, K = 8.3) lie in the field of our target. For normal SW Imaging objects
   brighter than 11 mag can leave residual images. However since we are using the polarimetric
   mode, the light is separated into 2 beams and the bright stars will be hidden behind
   the mask for most rotations. The waiver was granted given that we must split our
   observations into several exposures of DIT=2-4sec each (this is also neccessary
   in order to avoid saturation on the sky background).

Critical Observing Condition Constraints

• None

Time-Critical Aspects

• We wish to measure the polarisation of the target (GX339) on 6 separate
   dates to sample changes in polarisation with time (see proposal). We wish the 6
   dates to be spaced approximately weekly, but this is fairly flexible - any gap greater
   than 3 days is OK. For 2 of the epochs we will also observe a polarimetric standard
   star (calibration), which should be at similar airmass to the target. We prefer
   the standard star OB to be executed close in time to the target OB. This is our
   preferred sequence:
  
  Date 1:  GX339 Polarimetry 1,  Unpolarised standard WD 1620 1
  Date 2:  GX339 Polarimetry 2
  Date 3:  GX339 Polarimetry 3,  Unpolarised standard WD 1620 2
  Date 4:  GX339 Polarimetry 4
  Date 5:  GX339 Polarimetry 5
  Date 6:  GX339 Polarimetry 6
  
  Please do not execute the standard star OB on a night in which the target OB is
   not executed.

Special Execution Requirements

• None

Special Calibration Information

• We require the observations of a polarimetric standard star to be made
   on 2 dates to measure the instrumental polarisation (not included in the ISAAC Calibration
   Plan). The standard, which is taken fom the ISAAC polarimetry page, is WD 1620-391
   (a white dwarf) and has magnitudes J = 11.577, H = 11.708, K = 11.768.
  
  Please execute OBs of WD 1620 close in time to the target GX339. Please do not execute
   the standard star OB on a night in which the target OB is not executed.

ToO Information

• This is not a ToO but it is a DDT. Our target is currently in a unique
   variability state and will likely remain in this state for ~ 2 months.

ToO Activators List

• None

Is this a Pre-imaging run ?

• false

Pre-imaging Requirements

• None

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 ?

• YES

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

• YES

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

• YES

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

• N/A

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 submitted OBs for standard stars, did you use the provided StandardStar
 templates ?

• N/A

If you are using a specific offset pattern or position angle, did you
 check carefully the definition in the manual ?

• YES

If you are doing spectroscopy, did you draw the slit on the Finding Charts
 ?

• N/A

Did you enter the magnitude of the brightest star in the field-of-view
 in the 'Instrument Comments' field of each OB ?

• YES

If you use the MoveToPixel acquisition, have you given clear instructions
 on the FC and in the OB comment section as to how the field should be centered ?

• YES