README web version of /home/usg/OPS/MTS/readme_xml/readme_77002000

Principal Investigator Email Address

• sana@astro.ulg.ac.be

Estimated Total Execution Time (hours, including overheads)

• 8 hours

General Description

• We propose to acquire follow-up high S/N (>250) FEROS spectra of two
   relatively bright (V=7.2-7.9) early type SB2 binaries. The aim is to constrain the
   period and to derive the orbital parameters. To do so, we need to reach a sufficiant
   phase coverage. One of the critical points of this program is that the two periods
   are not constrained yet, but are most probably larger than a few months.
  
  We thus require about 10 spectra of each target spread over the entire P77. These
   should typically be separated by 2 weeks in order to probe the different probable
   periods. No scientific gain could be reached if the time separation between two
   obtained spectra is too small. The absolute minimal separation is 12 days.
  
  The S/N is another crucial aspect as the brightness ratio between the binary components
   is probably larger than 10. A S/N ratio > 250 is thus critical to unambiguously
   disentangle the component spectrum.

Waiver Requests

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Critical Observing Condition Constraints

• The present sources are reasonably bright, this program can thus be performed
   under about all seeing and cloud coverage conditions as long as a S/N > 250 is
   reached.
  
  Target can be observed during twilight.
  
  Exposure times were computed for thin cirrus coverage and seeing below 2". If this
   program is adopted as a backup program in the case of bad weather conditions (thick
   cirrus, awful seeing, large airmass) which prevent other observations, please increase
   the exposure time accordingly. Summing up several successive exposures to achieve
   the requested S/N is a valid option. 
  In any case, whatever the observing conditions, we will be able to extract useful
   information from our spectra only if the quested S/N > 250 is reached.

Time-Critical Aspects

• Please acquire one spectrum of each target on average once every 2-3 weeks.
   No scientific gain will be reached if the time separation between two obtained spectra
   is too small. The absolute minimal separation is 12 days.

Special Execution Requirements

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Special Calibration Information

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ToO Information

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ToO Activators List

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Is this a Pre-imaging run ?

• false

Pre-imaging Requirements

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Source(s) of Pre-imaging

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Pre-imaging sources not listed above

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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 ?

• 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?

• N/A

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 ?

• N/A

Did you set 'New Preset' flag in all acquisition templates to 'True'?

• YES

If you use any lamp, did you check that it should never be left on at
 the end of any OB?

• N/A