README web version of /home/usg/OPS/MTS/readme_xml/readme_83087101

Principal Investigator Email Address

• jorge@astro.up.pt

Estimated Total Execution Time (hours, including overheads)

• 10.5555

General Description

• This CRIRES observing run is dedicated to solar twin stars (stars very
   similar to the Sun). Under good conditions (seeing around 0.8-0.9arcsec, airmass
   <= 1.2-1.3 -except for some extremes cases where due to the coordinates a higher
   airmass was accounted for in the S/N calculations) the spectra should have S/N >=
   400 (typically about 400-460), but our targets can be observed even under worst
   conditions (seeing > 1 arcsec) because even spectra with S/N = 300 are still
   useful. Spectra with S/N < 200 are not very useful (they may only be useful to
   complete about 25% of the CRIRES science), and spectra with 200 < S/N < 300
   can still be used for about 50% of the goals of the proposal. 
  
  In short, ideally spectra should have S/N >= 400; spectra with S/N >= 300
   are still useful for most of the aims (although at a slightly lower precision) and
   spectra with S/N >= 200 can be partially useful (to carry out at least 50% of
   the proposed CRIRES science).
  
  There are two observing setups: 1047nm (54/0/n) and 1066.8nm (53/0/n). Since these
   regions are relatively clean of telluric lines, only 2 telluric calibration stars
   have been selected (specially to correct for small telluric absorption in the 1066.8nm
   setup). Indeed, even observation of only 1 telluric standard should be useful, and
   this is why we have not associated a telluric OB to each science OB, because the
   same telluric OB will be used for all science OBs.

Waiver Requests

• 083.D-0871B.01.WAV

Critical Observing Condition Constraints

• N/A.

Time-Critical Aspects

• Ideally the asteroid Ceres (OBs: MOV_Ceres-1047, MOV_Ceres-1066) should
   be observed as early as possible (i.e. April or May). It is brighter in April, but
   still observable until June. The asteroid will provide an standard reflected solar
   spectrum, and so it is of great importance to the present program. The exposure
   time for this object was computed assuming the worst conditions, i.e. that it may
   only be observed in June, but if it is observed in April (J = 6.4) or May (J = 6.8)
   it will allow us to obtain a better spectra (higher S/N) than if observed in late
   June (J = 7.5).

Special Execution Requirements

• Preference should be given to complete all OBs on a given target. If time
   for only one setup is available, the 1066.8nm (53/0/n) should be executed first.

Special Calibration Information

• The magnitudes and spectral type of the 2 telluric calibration stars (targets
   HD 105850 and HD 74706) are provided in the OBs. These are A-type stars with high
   rotation velocities (vsini), and will be useful to check and correct for small telluric
   features, specially in the 1066.8nm setup. 
  At least one of these calibration stars (either HD 105850 or HD 74706) should be
   observed, specially for the 1066.8nm setup. No more than two telluric calibration
   stars are needed, and this is why we have not associated a telluric OB to each science
   OB, because the same telluric OB could be used for all science OBs.

ToO Information

• N/A

ToO Activators List

• N/A

Do the README file and the instrument comments of the telluric stars
 OBs include the required S/N/pixel of the spectrum of the telluric star, its spectral
 type and allowed spectral range?

• YES

Do any OBs include wavelength or flatfield calibrations?

• NO

If you are observing Moving Targets, have you attached suitable ephemeris
 files to your OBs?

• YES

If the slit viewer guide star is different from the target, are the RA
 and DEC offsets accurate to within 0.05 arcsec and do they take into account the
 relative proper motion between the two objects?

• N/A

If you have preferences which OBs should be executed first for objects
 at similar RA, did you make use of the User Priority field in the OBs?

• YES