README web version of /home/usg/OPS/MTS/readme_xml/readme_76045000

Principal Investigator Email Address

• gdemarchi@rssd.esa.int

Estimated Total Execution Time (hours, including overheads)

• 8

General Description

• The purpose of this programme is to obtain accurate near-infrared magnitudes
   of pre main sequence (PMS) stars in the young star forming cluster R136 (30 Dor)
   in the LMC in order to determine their mass and age.
  
  The target coordinates identify a region located about 6 arcsec WNW of the centre
   of R136 where the S13 NACO field of view will be located (see finding chart). This
   region has been observed with the HST in the visible and near infrared and is known
   to contain several PMS stars that we intend to study. 
  
  The AO reference star (marked R1 in the finding charts) is Melnick 42 (aka Brey
   77), a O3 star of Wolf Rayet type WN with magnitudes: B=10.98, V=10.96, R=10.85,
   J=10.77, H=10.70, K=10.69. The reference star is located 5 arcsec away from the
   centre of the target field and is contained within the FOV of NACO for most of the
   planned jitter offsets. The reference star is also the brightest object within the
   FOV of NACO.
   
  All OBs are identical and can be executed in any order. Each OB contains of an acquisition
   template to acquire the R1 star. Since R1 is not too bright (V=10.96), it is not
   necessary to use a neutral density filter and the star will not saturate with the
   planned exposures with DIT=2 sec. For sky subtraction (if needed) a field devoid
   of bright stars has been identified as indicated 58 E of R1.
  
  Please note that the position angle of NACO throughout the entire OB is not zero,
   rather -37.8, as clearly indicated in the OB and finding chart. The S13 FOV of NACO
   is used throughout the entire run.
  
  Following acquisition, the telescope is slewed to the target field and two auto-jitter
   sequences are executed, one in J and one in H. The sequences use a four point jitter
   random pattern within a box of 5 arcsec on a side, in order to facilitate sky determination
   and subtraction from the images themselves. The values of DIT are kept small for
   both bands (~25-30 sec), in order to avoid the effects of saturation of the brightest
   stars. We have verified that, as indicated in the NACO manual, none of the objects
   will saturate more than a factor of four (i.e. the number of electrons per pixel
   does not exceed four times the full well).

Waiver Requests

• No Waiver Request was submitted

Critical Observing Condition Constraints

• None

Time-Critical Aspects

• None

Special Execution Requirements

• None

Special Calibration Information

• None

ToO Information

• None

ToO Activators List

• None

Is this a Pre-imaging run ?

• false

Pre-imaging Requirements

• None

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

If you have PSF reference star OBs, do the names of those OBs begin with
 PSF_ ?

• N/A

If there are Finding Charts attached to your OBs, is the field-of-view
 of at least one of these charts 2' x 2' (with clearly labelled field orientation)
 ?

• YES

Have you clearly marked and labelled your wavefront reference objects
 R1, R2, R3, ... (as specified in the NAOS Preparation Software) on your Finding
 Charts ?

• YES

Have you specified the magnitude of the brightest object in the field-of-view
 for each OB ?

• YES

Are there objects in any of your fields (including standard stars) which
 are brighter than the limits specified in the User Manual and on NACO web Pages
 ?

• NO

If the previous answer is yes, have you given a list of OBs and a justification
 for the brightness limit violation in the general description field ?

• N/A