README web version of /home/usg/OPS/MTS/readme_xml/readme_79051700

Principal Investigator Email Address

• prguez@iac.es

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 class. These systems are typically in a state of high
   mass transfer rate, where the accretion disc dominates the optical light. However,
   during occasional low states, 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 have 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). A waiver to do that has been granted.
  
  Apart from the spectrophotometric standard star observations (whose OB's may be
   executed either before or after the science target OB's), the strategy is to be
   on the science target continuously, i.e. executing the science OB's in a row DURING
   THE SAME NIGHT following the order described in 'Special Execution Requirements'.

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 on the same night.
   The waiver was approved (contact: Magda Arnaboldi).
   
  However, each science OB contains a target pointing and acquisition sequence. Obviously,
   if all the science target OBs are carried out in a contiguous sequence, no acquisition
   is necessary for all of them as the science target will always be centred on the
   slit.

Critical Observing Condition Constraints

• It is essential that the observations are executed consecutively on a
   single night so that the entire orbital period of the target is covered.

Time-Critical Aspects

• None

Special Execution Requirements

• Please execute the Science Target OBs in the following continuous sequence:
    Blue-0 Red-0 Red-1 Blue-1 Red-2 Red-3 Blue-2 Red-4 Red-5 Red-6 Red-7  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 most
   1 blue spectrum is taken during the eclipse (when the white dwarf is invisible).
   This frees the observation from additional orbital phase constraints. 
  The CAL OB's (spectrophotometric standard star) can be executed either before or
   after the science target run depending on which standard star is observed (it will
   be decided upon triggering). The exposure time is fixed at 60s which is fine with
   typical V=15 standards. Please reduce the exposure time to 15s if a brighter (V~12)
   standard is selected.

Special Calibration Information

• A spectrophotometric standard should be observed directly before or after
   the science target run (see Special Execution Requirements for more details).

ToO Information

• This ToO does not need a rapid response. The low states in the SW Sextantis
   stars typically last for 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 (visible for sufficiently long)
   we will activate the ToO.

ToO Activators List

• P Rodriguez-Gil

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 ?

• 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