README web version of /home/usg/OPS/MTS/readme_xml/readme_77003501

Principal Investigator Email Address

• nchristlieb@hs.uni-hamburg.de

Estimated Total Execution Time (hours, including overheads)

• 2:59:45

General Description

• Our program aims at measuring the abundances of Fe, and a few other important
   elements, of metal-poor stars that appear to have [Fe/H] < -3.5 from moderate-resolution
   (R=2000) spectroscopy. These estimates of [Fe/H] are indirect, since they are based
   on calibrations of the strength of Ca K. The history of the discovery of the two
   known stars with [Fe/H] < -5.0 has shown that the [Fe/H] of these stars can be
   overestimated by more than a factor of 10, due to e.g. blending of the Ca K line
   with interstellar absorption, or CH lines.
  
  Therefore we now want to obtain "snapshot" spectra (i.e., typically R=20,000 and
   S/N=50 per pixel) of stars with [Fe/H] < -3.5 for which high-resolution spectroscopy
   does not yet exists, in order to identify any stars with [Fe/H] < -5.0 among
   them.
  
  We have created three OBs for observations of HE1218-1828, which was estimated from
   moderate-resolution spectroscopy to have [Fe/H] = -3.8. We want to use the B390+R580
   standard setting, which covers a number of crucial absorption lines of Li, Na, Mg,
   Fe, Sr, Ba, and Eu. For this relatively faint star (B = 16.8), we aim at S/N = 35
   per rebinned pixel in the coadded spectrum at 400nm. The slit widths shall be 0.8''
   and 0.7'' arcsec in the blue and red arm, respectively.
  
  The constraint set corresponds to the observing conditions at the time when our
   Visitor Mode program was interrupted by 3 hours for Rapid Response Mode observations
   of a GRB, i.e., seeing 0.8'', and moon illumination 80%.

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 need secondary guiding, are there suitable objects within 30 arcsec
 from your target ?

• N/A