README web version of /home/usg/OPS/MTS/readme_xml/readme_76080402

Principal Investigator Email Address

• Boris.Gaensicke@warwick.ac.uk

Estimated Total Execution Time (hours, including overheads)

• 6h

General Description

• The aim of this program is to measure the radial velocity variation of
   the main-sequence
  donor star and the temperature of the white dwarf in a cataclysmic variable of the
   SW Sextantis type. These systems are typically in a state of high mass transfer,
   where the accretion disc dominates the optical light. However, during occasional
   low state, the mass transfer ceases, and both stellar components can be observed.
  
  The observations have therefore to be carried out as a TOO. This program consists
   of 6h FORS2 spectroscopy, that has to be carried out in a contiguous fashion in
   order to sample the
  entire orbital period of the system (which is around 4h for all targets).
  
  The observations are fairly straight-forward. Observe a flux standard with a blue
   and a red grating. Then observe the science target with the red grating, accumulating
   as many 600s exposures as fit into the allocated time. Interrupt this sequence three
   times to interleave a blue 600s spectrum of the target.

Waiver Requests

• A waiver request was submitted to execute the allocated 6h in a contiguous
   way, i.e. all OBs in this program should be observed consecutively. A second waiver
   request to assemble all the
  observations in a single 6h-long OB was rejected, and it was suggested to submit
   the program in individual OBs.
  
  As a consequence, each OB contains a target acquisition. Obviously if the OBs are
   carried out
  in a sequence, no acquistion is necessary, and the time should be filled with additional
   red spectra.

Critical Observing Condition Constraints

• It is essential that the observations are executed consecutively in a
   single night so to cover the orbital period of the target.

Time-Critical Aspects

• None

Special Execution Requirements

• Please execute the OBs in the following sequence:
  
  Blue-0
  Red-0
  Red-1
  Blue-1
  Red-2
  Red-3
  Red-4
  
  
  The blue spectra are necessary to measure the white dwarf temperature. As the system
   is eclipsing, the interleaving of three blue spectra in between the red ones assures
   that at maximum 1 blue spectrum is taken during the eclipse (when the white dwarf
   is invisible). This
  frees the observation from additional orbital phase constraints.

Special Calibration Information

• A spectrophotometric standard should be observed directly before or after
   the science target

ToO Information

• This TOO does not need a fast turn-around time. The low states in SW Sex
   stars last typically
  up to a few months, and an activation within 2-3 weeks is sufficient.
  
  The target stars are photometrically monitored regularly using the SMARTS telescopes.
   Should a low state be detected in one of the targets (and it is visible for sufficiently
   long) we will activate the TOO.

ToO Activators List

• BT Gaensicke

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 ?

• 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 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