README web version of /home/usg/OPS/MTS/readme_xml/readme_81010900

Principal Investigator Email Address

• pierre.kervella@obspm.fr

Estimated Total Execution Time (hours, including overheads)

• 3.0

General Description

• These HARPS observations of the eclipsing binary system Delta Velorum
   do not present any particular difficulty for HARPS. These are very bright stars
   (combined mV ~ 2.0), easy to find. There will actually be three stars in the HARPS
   field: the two main eclipsing components (Aa+Ab) and the fainter B component (about
   5% of the flux from the main pair in V) located ~1" away from the pair. The HARPS
   fiber should be centered on the main component Aa+Ab (do not care about the B star).
  
  Four of the OBs should be executed during the primary eclipse of 18 May 2008, and
   therefore they have strict time constraints (see also the "Time-critical aspects"
   section of the present README file). The annularity phase lasts about 2-3 h, i.e.
   +/- 1.5 hours around the central time. As the period of the system is 45 days, the
   eclipses do not happen very often during P81, but it would be really nice to have
   these data. We will need to disentangle the spectra of the three stars in the HARPS
   spectra and the dataa obtained during this eclipse will simplify this work.

Waiver Requests

• No Waiver Request.

Critical Observing Condition Constraints

• No critical observing conditions constraint.

Time-Critical Aspects

• Eclipses of Delta Vel Aa+Ab:
  
  Two of the OBs we submitted have to be executed during the primary eclipse of the
   Del Vel Aa+Ab system occuring on 18 May 2008. The corresponding time constraints
   have been specified in the OBs themselves. For reference, the dates of the eclipse
   center is 18 May 2008 at UTC 01:27.
  
  The annularity phase of the eclipse last about 2-3 h, i.e. +/- 1.5 hours around
   the given UT time. The complete duration of the eclipse (from ingress to egress)
   is approximately 12 h for the primary eclipse.
  
  Remark: The primary eclipse (the deeper in photometry) is when the smaller, cooler
   star (Ab, A5V) passes in front of the bigger, hotter star (Aa, A1V), causing an
   annular eclipse. The secondary eclipse (shallower in photometry) is when the cooler
   star is totally eclipsed by the hotter one.

Special Execution Requirements

• No special requirements.

Special Calibration Information

• No special calibrations.

ToO Information

• NA

ToO Activators List

• NA

Is this a Pre-imaging run ?

• false

Pre-imaging Requirements

• NA

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 ?

• 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 ?

• YES