README web version of /home/usg/OPS/MTS/readme_xml/readme_78002200

Principal Investigator Email Address

• eric.lagadec@manchester.ac.uk

Estimated Total Execution Time (hours, including overheads)

• 4h

General Description

• This programs aims to study the dusty structure at the center of the bipolar
   post-AGB star OH231.8. We observed this star previously with UT3-UT4 baseline, which
   orientation is roughly perpendicular to the bipolar lobes seen in the optical. We
   detected a dusty structure. To know if this strutcture is a disc or a shell, we
   need observations with baselines having different orientations. We thus want to
   observe it with 4 different  UT2-UT3 baselines.

Waiver Requests

• Our waiver request:078.D-0022A.01.WAV was accepted.
  We wanted to change from SCI_PHOT to HIGH_SENS mode in order to optimize the flux.

Critical Observing Condition Constraints

• We need a seeing smaller than 1.2 arcsec. The target is extended and fringe
   might not be detected in bad seeing conditions.

Time-Critical Aspects

• We want to obtain fringes in 4 different hour angles.
  The ideal observations would be to execute the 4 science OBs in the same night.
  If the continuous observations are not guaranteed,
   each OB should be executed in specified sidereal time.
   In this case, it is desirable that the entire observations will be
   completed in reasonable time (within 2 months) since the target
   is variable. (practically, this 2 month variable constrain is almost
   same time as observable time of the target.)

Special Execution Requirements

• ---(Empty)---

Special Calibration Information

• HD61935 is the primary calibration star and HD50778 the second

ToO Information

• ---(Empty)---

ToO Activators List

• ---(Empty)---

Is this a Pre-imaging run ?

• false

Pre-imaging Requirements

• The target has a different morphology in the optical and the infrared.
  Thus the image in the guide and MIDI aquisition images will be different.
  In the optical we see the bipolar lobes of the object.
  In the mid-infrared, the central region is the brightest.
  This is what we want to observe with MIDI.

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 ?

• N/A

Did you indicate for each science star OB the corresponding calibrator
 star OB (and vice versa) in the 'Instrument Comments' field ?

• YES

Did you check that your chosen calibrator is bright enough for the instrument
 mode used ?

• YES

If you use calibrator stars which are not in the CalVin database, did
 you specify their characteristics in the README file and in the OBs ?

• N/A