README web version of /home/usg/OPS/MTS/readme_xml/readme_83076500

Principal Investigator Email Address

• elena@damir.iem.csic.es

Estimated Total Execution Time (hours, including overheads)

• 37:31:25.00

General Description

• The scope of this project is the determination of the chemical abundances
   of  hot stars in massive clusters within the Milky Way. We need to obtain high SNR
   (~200) mid-resolution spectra  of these stars in order to perform quantitative spectroscopy
   through the fit of atmospheric models. Our diagnostic lines are the hydrogen and
   helium lines (HeI and HeII), together with other fainter lines (FeII, MgII..etc).
  Although we proposed to observe a total of 10 clusters, the constraints imposed
   by the maximum of 2 settings per OB have increased our overheads substantially.
   Therefore, we have left out two clusters from our sample that do not show strong
   Paschen alpha emission (our tracer of hot stars). In this way, the study we attemp
   to do will not be compromised.
  Settings:
  The OBs named with a *_slit?_K have TWO settings in the same OB (centred at 2.09
   and 2.21 microns).
  OBs with name ending with _slitn_KL have only one setting (2.31 micron). 
  
  Slit widths:
  We are using the 0.3" slit (length 120") and the 0.8" (effective 90" length)
   
  Finding Charts:
  Our finding charts depict the alignment of the slit on the sky. They are centered
   on one star (labeled in red) and oriented so that they also include the second star
   (labeled in blue).  
  
  Acquisition:
  Our acquisition template is conceived so that the telescope is preset to the middle
   point between the two stars, always with the star labeled in red in the FC at the
   bottom of the slit and the blue one at the top. On-site refining of the PA and position
   of the stars may be  needed to place the two stars to an equally distant positon
   from the middle of the detector.
  
  Nod Throw:
  
  Two effects have been considered when determining the positioning of our objects
   along the slit:
  -The presence of dust grains and flakes: we have discarded the central 37" of the
   FOV
  -The transmission defect in the 0.8" slit: affects the regions 13"-20" and 99"-103"
   from the bottom of the slit
  
  Since our observational strategy consists in positioning two stars along the slit,
   the separation between these two stars is a determining factor to choose both the
   nod throw  in order to prevent the stars from falling on the zones of avoidance
   (always considering the middle point between the two stars to be observed).
  Several cases are possible considering a jitter of 3":
  
  0.3" slit: A nod throw of 81" allows separations between two stars <35"
  0.8" slit: A nod throw of 61" allows separations between two stars  <12"
             A nod throw of 81" allows separations between two stars in the range
   14.6"-35"

Waiver Requests

• We submitted a request for a deadline extension on 3 Feb that was approved
   and notified on 4 Feb

Critical Observing Condition Constraints

• Our observations require nights classified as CLR with a maximum seeing
   of 0.8"

Time-Critical Aspects

• N/A

Special Execution Requirements

• Our priority for this project is to reach a high completeness per  cluster
   in order to conduct a robust abundance study for each of them. Besides, we have
   prioritized the clusters as it follows:
  
  DBSB2003T3+45 1
  MERCER30 1
  MERCER70 1
  MERCER81 1
  MERCER20 1
  MERCER23 1
  MERCER9  2
  MERCER17 2

Special Calibration Information

• Telluric standards from the calibration plan should be of spectral type
   late-B early-A dwarf stars.

ToO Information

• N/A

ToO Activators List

• N/A

Is this a Pre-imaging run ?

• false

Pre-imaging Requirements

• N/A

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 ?

• 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 submitted OBs for standard stars, did you use the provided StandardStar
 templates ?

• N/A

If you are using a specific offset pattern or position angle, did you
 check carefully the definition in the manual ?

• YES

If you are doing spectroscopy, did you draw the slit on the Finding Charts
 ?

• YES

Did you enter the magnitude of the brightest star in the field-of-view
 in the 'Instrument Comments' field of each OB ?

• YES

If you use the MoveToPixel acquisition, have you given clear instructions
 on the FC and in the OB comment section as to how the field should be centered ?

• YES